{"slug":"resistance-training","name":"Resistance training","aliases":["Strength training","Lifting"],"kind":"lever","system":"mitochondria","unit":"sessions per week","unitNote":"Guidelines count days a week; the mortality cohorts counted minutes a week. Both are quoted as the source states them.","answer":"In the cohort meta-analyses, adults who did any resistance training had 15 to 21 percent lower all-cause mortality than those who did none, with the lowest risk at about 30 to 60 minutes a week and no further benefit, by one reading a fading one, above about 130 to 140 minutes a week; the WHO and US guidelines ask for muscle-strengthening work on 2 or more days a week. In randomized trials it lowers HbA1c by about half a percentage point in diabetes, lowers blood pressure by about 2 to 3 mm Hg, and raises spine bone density when the load is heavy.","summary":"Resistance training is any exercise that makes muscles work against a load until they adapt. Guidelines from the WHO and the US Department of Health and Human Services ask for it on 2 or more days a week, the cohorts find the lowest mortality at modest weekly volumes, and the trials show measurable effects on blood sugar, blood pressure, bone and function at any age, including people in their nineties.","whatItIs":[{"text":"Resistance training, called muscle-strengthening activity in the guidelines, is exercise that loads a muscle against resistance (weights, bands, machines or body weight) hard enough that it adapts by getting stronger and, more slowly, larger. The WHO 2020 guideline places it alongside 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous aerobic activity a week, and recommends it at moderate or greater intensity, involving all major muscle groups, on 2 or more days a week, a strong recommendation it rates as resting on moderate-certainty evidence.","cites":["bull2020"],"grade":"A"},{"text":"The US Physical Activity Guidelines, second edition, make the same call: muscle-strengthening activities on 2 or more days a week for adults, with balance training added for older adults, and the same guidance for adults with chronic conditions who are able. The committee behind them answered 38 questions and 104 subquestions from a systematic review, and notes that about 80 percent of US adults and adolescents are insufficiently active.","cites":["piercy2018"],"grade":"A"},{"text":"The reason a physician cares is that strength, and to a lesser degree muscle mass, predicts survival. The 2019 European consensus defines sarcopenia as a muscle disease rooted in adverse changes that accrue across a lifetime, makes low muscle strength its key characteristic, uses low muscle quantity or quality to confirm the diagnosis, and sets the strength cut-offs at a grip below 27 kg in men and 16 kg in women, or more than 15 seconds for five chair rises. In the cohort that measured both, strength predicted survival and muscle size did not, which is why the entry treats strength as the number to watch.","cites":["cruzjentoft2019","newman2006"],"grade":"B"}],"origins":[{"text":"Skeletal muscle is the body's largest organ, and in the past two decades it has been recognized as an endocrine one. Muscle fibers produce and release several hundred peptides, named myokines, that act within the muscle and on fat, liver, pancreas, bone and brain: interleukin-6 with systemic effects on liver, fat and immune cells, the bone-building factors IGF-1 and FGF-2, FSTL-1 for the vessel lining, and irisin, which drives brown-fat-like development. Most of them are released only when the muscle contracts, so the authors of the founding review proposed that physical inactivity produces an altered myokine response, a candidate mechanism for the link between sitting and chronic disease. Muscle is also the body's amino-acid reserve: the principal store that keeps protein synthesis going in vital organs when nothing is being absorbed from the gut, and the source of the precursors the liver turns into glucose, which is why the loss of muscle in illness and age matters beyond strength.","cites":["pedersen2012","wolfe2006"],"grade":"C"},{"text":"The reason lifting has to be prescribed is evolutionary. Humans were selected for regular, moderate physical activity into late age, but because food energy was limited they were also selected to avoid unnecessary exertion, and most organ systems evolved to need the stimulus of activity to match capacity to demand; selection never had to cope with the long-term effects of chronic inactivity. That is Lieberman's exercise paradox: people avoid exercise for the same reason they need it. The modern Hadza foragers of Tanzania make the point in numbers. Forty-six adults wearing heart-rate monitors averaged about 135 minutes a day of moderate-to-vigorous activity, over 14 times the amount recorded in large US epidemiological studies, held it across the lifespan, and showed a low prevalence of hypertension among 198 adults measured. They also rest for about 9.9 hours a day, as much as office workers, but often in squatting and kneeling postures that keep the leg muscles active, which the authors call active rest and the basis of an inactivity mismatch hypothesis: human physiology expects muscles that contract through the day. A heavy load lifted two or three times a week is the modern stand-in for a life that loaded muscle continuously.","cites":["lieberman2015","raichlen2017","raichlen2020"],"grade":"C"},{"text":"On the shelf, muscle sits upstream of the metabolic markers. Under an insulin clamp, about 90 percent of infused glucose in healthy adults and 87 percent in people with type 2 diabetes was taken up by peripheral tissues, essentially muscle, and the diabetic subjects' leg glucose uptake was 45 percent lower, so muscle is both the main glucose sink and the main site of insulin resistance; that is the physiological link from a strength program to fasting insulin, HOMA-IR, HbA1c and triglycerides. Muscle also sets resting energy use: one review estimates that inactive adults lose 3 to 8 percent of muscle mass a decade with a matching fall in resting metabolic rate, and that 10 weeks of training can add about 1.4 kg of lean weight and raise resting metabolic rate by about 7 percent, estimates from a narrative review rather than a trial. Bone and blood pressure answer to the same loading, and strength predicts survival partly because it summarizes all of this at once: the grip-strength cohorts below are reading the organ, not the hand.","cites":["defronzo1985","westcott2012","pedersen2012"],"grade":"C"}],"labRange":{"typical":"Muscle-strengthening activity at moderate or greater intensity, involving all major muscle groups, on 2 or more days a week (WHO 2020; US Physical Activity Guidelines 2018)","claims":[{"text":"The WHO 2020 guideline recommends muscle-strengthening activities at moderate or greater intensity that involve all major muscle groups on 2 or more days a week, as a strong recommendation supported by moderate-certainty evidence, in addition to the aerobic target. It adds that there was no evidence to support a dose-response association with higher volumes of muscle-strengthening activity, which is why the guidance is a floor without a ceiling.","cites":["bull2020"],"grade":"A"},{"text":"The US guidelines match it at 2 or more days a week, ask older adults for multicomponent activity that includes balance as well as aerobic and strengthening work, and state the general principle that the people doing the least gain the most from a modest increase, with additional benefit from more.","cites":["piercy2018"],"grade":"A"},{"text":"Neither guideline specifies sets, repetitions or load; those come from the training literature in the levers below. In practice two sessions a week is the floor the guidelines set, and the cohort meta-analysis that mapped the dose curve concluded that the current recommendation of at least 2 days a week could be reasonable, while a higher volume may require caution.","cites":["momma2022","bull2020"],"grade":"B"}]},"evidence":{"headline":"Any resistance training beat none in every cohort, with 15 to 21 percent lower all-cause mortality; risk sat lowest at about 30 to 60 minutes a week and was no longer lower than none above about 130 to 140 minutes a week, a tail the authors call unclear. Grip strength predicted death better than systolic blood pressure in 17 countries. Trials show lower HbA1c, lower blood pressure and higher bone density; no trial has measured mortality.","scale":{"min":0,"max":7,"ticks":[0,1,2,3,4,5,6,7]},"bands":[{"label":"Guideline: muscle-strengthening activity on 2 or more days a week","low":2,"high":7,"tone":"lab","source":"WHO 2020; US Physical Activity Guidelines 2018"},{"label":"None: 15 to 21 percent higher all-cause mortality than any amount","low":0,"high":0,"tone":"caution","source":"Momma 2022; Shailendra 2022; Saeidifard 2019"},{"label":"Lowest mortality in the cohorts: about 30 to 60 minutes a week, roughly one to two sessions","low":1,"high":2,"tone":"evidence","source":"Momma 2022; Shailendra 2022"},{"label":"Risk still below none up to about 130 to 140 minutes a week; strength and mass keep rising with volume in trials","low":2,"high":4,"tone":"neutral","source":"Momma 2022; Ralston 2017; Schoenfeld 2017"},{"label":"J-curve tail: no mortality benefit over none in the cohorts above about 130 to 140 minutes a week; authors call it unclear","low":5,"high":7,"tone":"caution","source":"Momma 2022; Shailendra 2022"}],"claims":[{"text":"The largest synthesis pooled 16 prospective cohorts of adults without severe illness. Muscle-strengthening activity was associated with a 10 to 17 percent lower risk of all-cause mortality, cardiovascular disease, total cancer, diabetes and lung cancer, independent of aerobic activity. For all-cause mortality, seven studies with 42,133 deaths among 263,058 participants gave a relative risk of 0.85. The dose curve from six studies (236,331 participants) was J-shaped: the lowest risk, relative risk 0.83, sat at 40 minutes a week, the estimate stayed below 1.00 up to about 140 minutes a week, and the maximum reductions for mortality, cardiovascular disease and cancer fell at about 30 to 60 minutes a week; for diabetes the curve was L-shaped, with a large reduction up to 60 minutes a week and no rebound. Adults who did both strengthening and aerobic activity had a relative risk of 0.60 for all-cause mortality against those who did neither. The authors graded the certainty of the all-cause mortality evidence very low.","cites":["momma2022"],"grade":"B"},{"text":"Two other meta-analyses agree on the direction and the shape. Across 10 studies, any resistance training against none carried a 15 percent lower all-cause mortality (relative risk 0.85), 19 percent lower cardiovascular mortality (0.81) and 14 percent lower cancer mortality (0.86); a dose-response analysis of four studies found a maximum reduction of 27 percent at around 60 minutes a week (0.74), with the reduction diminishing at higher volumes. Across 11 studies with 370,256 participants followed a mean of 8.85 years, resistance training alone carried a hazard ratio of 0.79 for all-cause mortality and 0.60 when combined with aerobic exercise, a borderline association with cardiovascular mortality (0.83) and no significant association with cancer mortality.","cites":["shailendra2022","saeidifard2019"],"grade":"B"},{"text":"The high-volume tail of the J is the least certain part of the curve, and it should be read as association, not harm. It rests on a small number of studies; 13 of the 16 cohorts measured lifting by self-report questionnaire and three by interview, none measured load or progression, and the authors write that the influence of a higher volume on mortality, cardiovascular disease and cancer is unclear. A curve that flattens or turns up at the high end can also arise when the heaviest self-reported lifters differ from everyone else in ways the models did not capture. No randomized trial has tested resistance training against mortality at any dose.","cites":["momma2022","shailendra2022"],"grade":"B"},{"text":"Strength itself, measured as grip, predicts death across populations. In the PURE study, 139,691 adults aged 35 to 70 in 17 countries were followed a median of 4.0 years, during which 3,379 died; each 5 kg lower grip strength carried a hazard ratio of 1.16 for all-cause mortality, 1.17 for cardiovascular mortality, 1.07 for heart attack and 1.09 for stroke, consistent across country-income levels, and grip strength was a stronger predictor of all-cause and cardiovascular death than systolic blood pressure. It did not predict new diabetes, falls or fracture. The authors ask for trials to test whether improving strength reduces mortality, which is the open question that separates the marker from the lever.","cites":["leong2015"],"grade":"B"},{"text":"In UK Biobank, 502,293 adults aged 40 to 69 (54 percent women) were followed a mean of 7.1 years with 13,322 deaths. Each 5 kg lower grip carried a hazard ratio of 1.20 in women and 1.16 in men for all-cause mortality, and 1.19 and 1.22 for cardiovascular mortality, with higher hazards in the younger participants; weakness, defined as a grip below 26 kg in men and 16 kg in women, raised the hazard for nearly every outcome. Adding grip to an office risk score of age, sex, diabetes, body mass index, systolic blood pressure and smoking improved its discrimination for all-cause mortality by a C-index change of 0.013, a real but small gain.","cites":["celismorales2018"],"grade":"B"},{"text":"Strength predicts better than mass. In the Health ABC cohort of 2,292 adults aged 70 to 79, with 286 deaths over an average of 4.9 years, quadriceps strength carried a crude hazard ratio of 1.51 per standard deviation in men and 1.65 in women, muscle size by CT or DXA was not strongly related to mortality, and adjusting strength for muscle area barely moved it; grip gave similar estimates. Mass is not nothing: among 3,659 adults aged 55 and over in the US national survey, with the underweight and early deaths excluded, the top quarter of muscle mass index by bioimpedance had an adjusted mortality risk ratio of 0.81 against the bottom quarter. Both are associations in older adults.","cites":["newman2006","srikanthan2014"],"grade":"B"},{"text":"The metabolic effect has trial evidence. Across 47 randomized trials with 8,538 patients with type 2 diabetes, structured resistance training lowered HbA1c by 0.57 percentage points against control, aerobic training by 0.73 and the two combined by 0.51; programs over 150 minutes a week lowered it by 0.89 and programs of 150 minutes or less by 0.36. An earlier pooling of 13 trials in people with abnormal glucose regulation found resistance training lowered HbA1c by 0.48 points, fat mass by 2.33 kg and systolic blood pressure by 6.19 mm Hg, with no significant change in total, LDL or HDL cholesterol or triglycerides.","cites":["umpierre2011","strasser2010"],"grade":"A"},{"text":"For blood pressure, 93 randomized trials with 5,223 participants, 29 of them dynamic resistance groups, found that dynamic resistance training lowered systolic pressure by 1.8 mm Hg and diastolic by 3.2, against 3.5 and 2.5 for endurance training; the largest resistance effect was in prehypertensive participants (4.0 over 3.8). Five small isometric groups showed much larger falls (10.9 over 6.2), a signal the authors flag as resting on few studies.","cites":["cornelissen2013"],"grade":"A"},{"text":"For bone, heavy loading works where light loading does not. In the LIFTMOR trial, 101 postmenopausal women with low bone mass (mean age 65) were randomized to eight months of twice-weekly, 30-minute supervised high-intensity resistance and impact training (five sets of five at over 85 percent of one-repetition maximum) or a home-based low-intensity program; lumbar spine density rose 2.9 percent against a 1.2 percent fall, femoral neck density held (0.3 percent against minus 1.9), every functional measure improved, and the one adverse event was a minor back spasm. A meta-analysis of 24 trials in postmenopausal women found resistance training raised femoral neck and lumbar spine density overall (standardized mean differences 0.30 and 0.31), but the effect was carried by programs that combined resistance with impact or weight-bearing work; resistance alone gave a positive effect that did not reach significance.","cites":["watson2018","zhao2015"],"grade":"B"},{"text":"Age is not a barrier. In 100 frail nursing-home residents with a mean age of 87 (range 72 to 98), ten weeks of high-intensity progressive resistance training raised muscle strength by 113 percent against 3 percent in non-exercisers, gait speed by 11.8 percent against a 1.0 percent decline, and stair-climbing power by 28.4 percent against 3.6; 94 percent completed the study, and a multinutrient supplement without exercise changed no primary outcome.","cites":["fiatarone1994"],"grade":"B"}]},"levers":[{"name":"Two sessions a week, with progressive load","effect":"enough for strength; more volume buys more, with diminishing returns","claim":{"text":"Across 22 studies, strength gains rose with training frequency (effect sizes 0.74, 0.82, 0.93 and 1.08 for one, two, three and four or more sessions a week), but when weekly volume was equated the frequency effect disappeared, and it was not significant in middle-aged and older adults; frequency is mostly a way to fit in more sets. Volume itself has a graded dose-response: medium and high weekly set numbers beat low ones for strength across 61 treatment groups, and for muscle size each additional weekly set added about 0.37 percent to the gain, with higher-volume groups gaining about 3.9 percent more than lower-volume ones across 15 studies. Two sessions a week is where the guidelines, the mortality curve and the strength trials overlap; progressive load, meaning the weight goes up as the muscle adapts, is the common feature of every trial that worked.","cites":["grgic2018","ralston2017","schoenfeld2017"],"grade":"B"}},{"name":"Protein, up to about 1.6 g per kg of body weight a day","effect":"adds strength and lean mass to the training; adds nothing above that intake","claim":{"text":"Pooling 49 randomized trials with 1,863 healthy adults training for six weeks or more, protein supplementation added 2.49 kg to one-repetition-maximum strength and 0.30 kg to fat-free mass, with measurable increases in muscle fiber cross-section. The benefit shrank with age and was larger in people already trained, and supplementing beyond a total intake of about 1.6 g per kg a day (break point 1.62) produced no further gain in fat-free mass. Protein helps the training; it does not replace it, as the nursing-home trial above showed with a supplement that did nothing without exercise.","cites":["morton2018","fiatarone1994"],"grade":"B"}},{"name":"Starting from none","effect":"the largest step on the whole curve","claim":{"text":"In every mortality meta-analysis the biggest difference is between none and some: 15 percent lower all-cause mortality for any resistance training against none across 10 studies, 21 percent across 11, and 15 percent across seven. The US guidelines state the general rule that the least active gain the most from a modest increase. The first session a week matters more than the fourth.","cites":["shailendra2022","saeidifard2019","momma2022","piercy2018"],"grade":"B"}},{"name":"Pairing it with aerobic activity","effect":"lower mortality than either alone in the cohorts","claim":{"text":"Adults who reported both muscle-strengthening and aerobic activity had a relative risk of 0.60 for all-cause mortality against those who did neither, and resistance training combined with aerobic exercise carried a hazard ratio of 0.60 against 0.79 for resistance training alone across 370,256 participants. Both guidelines ask for both. The cohorts cannot say whether the pairing is additive or whether people who do both differ in other ways.","cites":["momma2022","saeidifard2019","bull2020"],"grade":"B"}},{"name":"What it does to HbA1c, insulin and visceral fat","effect":"lowers HbA1c by about half a point in diabetes; raises insulin sensitivity","claim":{"text":"Structured resistance training lowered HbA1c by 0.57 percentage points in type 2 diabetes across randomized trials, and by 0.48 in an earlier pooling. In a small 16-week trial, nine older men with type 2 diabetes who trained twice a week at 50 to 80 percent of their one-repetition maximum, with no diet change and no change in body weight, raised their insulin sensitivity by 46.3 percent on a minimal-model test, cut visceral abdominal fat by 10.3 percent on CT and lowered fasting glucose by 7.1 percent (146.6 to 135.0 mg/dL) while eating 15.5 percent more. Nine men is a mechanism study, not a verdict, but it shows what two sessions a week can do to the markers on this shelf: fasting insulin, HOMA-IR and HbA1c.","cites":["umpierre2011","strasser2010","ibanez2005"],"grade":"A"}},{"name":"What it does to blood pressure","effect":"lowers it by about 2 to 3 mm Hg; more in prehypertension","claim":{"text":"Dynamic resistance training lowered resting systolic pressure by 1.8 mm Hg and diastolic by 3.2 across 29 randomized groups, with the largest falls, 4.0 over 3.8, in prehypertensive participants; in people with abnormal glucose regulation the pooled systolic fall was 6.19 mm Hg. Small numbers per person, population-sized when they are spread across everyone who lifts.","cites":["cornelissen2013","strasser2010"],"grade":"A"}},{"name":"What it does to bone","effect":"raises spine density when the load is heavy or paired with impact; little when it is light","claim":{"text":"Twice-weekly, 30-minute heavy lifting with impact raised lumbar spine density 2.9 percent in eight months in postmenopausal women with low bone mass, while the low-intensity comparison group lost 1.2 percent; across 24 trials, combined resistance-and-impact programs raised hip and spine density and resistance alone did not reach significance. The bone responds to the size and speed of the strain, which is why light machine circuits show little and supervised heavy lifting shows more.","cites":["watson2018","zhao2015"],"grade":"B"}},{"name":"What it does to creatinine, ALT, AST and creatine kinase","effect":"raises all four, for about a week after an unfamiliar session, and creatinine for as long as the muscle lasts","claim":{"text":"In 15 healthy men unused to lifting, one hour of weightlifting raised AST, ALT, lactate dehydrogenase, creatine kinase and myoglobin significantly, and they stayed raised for at least seven days; bilirubin, GGT and alkaline phosphatase did not move, which is the pattern that tells muscle from liver. Serum creatinine tracks lean mass rather than kidney function: among 170 healthy adults, the moderately or intensely active group ran a mean creatinine of 1.04 mg/dL against 0.95 in the sedentary, with more lean mass (55.3 against 48.5 percent), while cystatin C did not differ, and lean mass stayed related to creatinine after adjustment for protein and meat intake. A well-muscled person can print a lower eGFR than their kidneys deserve, and cystatin C sorts it out.","cites":["pettersson2008","baxmann2008"],"grade":"C"}}],"caveats":[{"text":"The mortality evidence is observational and the exposure is self-reported. Thirteen of the 16 cohorts in the largest meta-analysis measured muscle-strengthening activity by questionnaire and three by interview; none measured load, sets or progression, and the authors rated the certainty of the all-cause mortality evidence very low and could not test for publication bias. The association is consistent in direction across every study, which is why it is graded B here, but a 15 percent lower mortality in people who report lifting is not the same as a 15 percent lower mortality from lifting.","cites":["momma2022","shailendra2022"],"grade":"B"},{"text":"Blood drawn within a week of hard or unfamiliar lifting can read as liver or kidney injury. ALT and AST stayed significantly raised for at least seven days after a single hour of weightlifting in men unused to it, with creatine kinase and myoglobin highly elevated, and creatinine runs higher in people with more muscle regardless of exercise. A raised ALT or a lowered eGFR in someone who trains deserves the question of when they last lifted, a creatine kinase alongside, and a cystatin C for the kidney, before it earns a label.","cites":["pettersson2008","baxmann2008"],"grade":"C"},{"text":"Strength and mass are different measurements with different meaning. In Health ABC, strength predicted mortality and muscle size by CT or DXA did not, and adjusting one for the other barely changed the strength signal; the European consensus accordingly makes low strength the defining feature of sarcopenia and uses mass to confirm it. A scale, a bioimpedance reading or a DEXA lean-mass number is not a strength test, and a program that adds mass without adding strength has not been shown to add years.","cites":["newman2006","cruzjentoft2019"],"grade":"B"},{"text":"Injury rates are low but not zero, and they concentrate in the spine, shoulder and knee. Across 20 epidemiology studies of the weight-training sports, bodybuilding had 0.24 to 1 injury per 1,000 hours of training and strongman 4.5 to 6.1, with strains, tendinitis and sprains the usual types and few differences by age, sex or standard; a separate review put weightlifting at 2.4 to 3.3 and powerlifting at 1.0 to 4.4 injuries per 1,000 hours, similar to other non-contact strength sports and low compared with contact sports. Those are competitive athletes training hard; most of the studies were retrospective and of low methodological quality, so the figures bound the risk rather than fix it.","cites":["keogh2017","aasa2017"],"grade":"C"},{"text":"The trial effects are modest per person and depend on the program. The HbA1c reduction from resistance training alone (0.57 points) had a confidence interval that reached almost to zero, the blood-pressure effect of dynamic resistance training (1.8 mm Hg systolic) likewise, and the bone effect appeared only with heavy or impact loading; a light circuit done without progression may deliver little of what the trials measured.","cites":["umpierre2011","cornelissen2013","zhao2015"],"grade":"B"}],"seeAPhysician":["Chest pain, pressure, unusual breathlessness, palpitations, faintness or a near-blackout during or just after exertion, which calls for an evaluation before the next session, not after it.","Very dark or cola-colored urine, severe muscle pain or swelling, or weakness out of proportion to the session in the day or two after an unusually hard workout, which can mean muscle breakdown (rhabdomyolysis) and needs same-day blood tests.","A bulge or ache in the groin or abdominal wall that appears with straining, which can be a hernia and should be examined before heavy lifting continues.","A joint that swells, locks, gives way or stays painful for more than a few days after training, or back pain with numbness, weakness or any change in bladder or bowel control.","Blood pressure that is not controlled, a known aortic aneurysm, recent eye surgery or retinal disease, or heart failure or valve disease, before starting heavy lifting or breath-holding under load; a physician can set the limits rather than forbid the work.","A raised ALT, AST or creatinine on a routine panel in someone who trains: it may be the training, and a physician can time the repeat draw and add creatine kinase and cystatin C."],"openQuestions":["No randomized trial has tested resistance training against mortality or cardiovascular events at any dose. The whole survival curve is observational, and the trials that exist measured markers, strength and function.","The ideal weekly volume is unknown. The cohorts put the lowest mortality at about 30 to 60 minutes a week by self-report and see the benefit fade above about 130 to 140, while the strength and hypertrophy trials keep improving with more sets; whether the high-volume tail is harm, confounding or reverse causation has not been tested.","Whether strength or mass is the causal factor, or whether both are markers of something else such as mitochondrial function, nerve health or overall fitness, is unsettled. Grip strength predicts death better than muscle size, but a trial that raises strength and follows survival has not been done.","Women and older adults are under-represented in the training-volume literature. The frequency effect on strength was significant in women and not men, and absent in middle-aged and older adults, in a meta-analysis built mostly on untrained young participants; the bone trial that worked enrolled only postmenopausal women; the nursing-home trial was 63 women and 37 men. How the dose-response differs by sex and decade is not yet mapped.","Whether the mortality association is specific to lifting or belongs to any vigorous muscular work, and whether the pairing with aerobic activity is additive or simply marks people who do both, cannot be answered by the cohorts."],"questions":[{"q":"How many days a week should I lift to live longer?","a":"The WHO and US guidelines ask for muscle-strengthening work on 2 or more days a week. In the cohort meta-analyses, adults who did any resistance training had 15 to 21 percent lower all-cause mortality than those who did none, and the lowest risk sat at about 30 to 60 minutes a week, which is roughly two sessions; above about 130 to 140 minutes a week the mortality benefit was no longer visible, a tail the authors call unclear and that no trial has tested. The strength and bone trials that worked used two supervised sessions a week with progressively heavier loads."},{"q":"Is lifting weights better than cardio for longevity?","a":"The cohorts say both, not either. Resistance training alone carried a hazard ratio of about 0.79 for all-cause mortality and aerobic plus resistance about 0.60 across 370,256 people, and the WHO guideline asks for 150 to 300 minutes of aerobic activity plus strengthening on 2 or more days a week. In trials, aerobic training lowered HbA1c slightly more and resistance training preserved strength and bone, which aerobic work does not; the one thing the evidence does not support is substituting one for the other."},{"q":"Can lifting weights raise my creatinine or liver enzymes?","a":"Yes, both. In men unused to lifting, one hour of weightlifting raised ALT and AST significantly for at least seven days, with creatine kinase and myoglobin far higher, while GGT, alkaline phosphatase and bilirubin stayed normal; that pattern is muscle, not liver. Creatinine runs higher in people with more muscle whether or not they trained that week, so a muscular person can print a lower eGFR than their kidneys deserve. A draw a week after the last hard session, with creatine kinase and cystatin C alongside, tells the two apart."}],"citations":[{"id":"bull2020","authors":"Bull FC, Al-Ansari SS, Biddle S, et al.","title":"World Health Organization 2020 guidelines on physical activity and sedentary behaviour","journal":"British Journal of Sports Medicine","year":2020,"pmid":"33239350","doi":"10.1136/bjsports-2020-102955","type":"guideline","finding":"Adults should do 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous aerobic activity a week, plus muscle-strengthening activities at moderate or greater intensity involving all major muscle groups on 2 or more days a week (strong recommendation, moderate-certainty evidence); no evidence of a dose-response with higher strengthening volumes.","url":"https://pubmed.ncbi.nlm.nih.gov/33239350/"},{"id":"piercy2018","authors":"Piercy KL, Troiano RP, Ballard RM, et al.","title":"The Physical Activity Guidelines for Americans","journal":"JAMA","year":2018,"pmid":"30418471","doi":"10.1001/jama.2018.14854","type":"guideline","finding":"Adults should do muscle-strengthening activities on 2 or more days a week alongside 150 to 300 minutes of moderate aerobic activity; older adults should add balance training; about 80 percent of US adults and adolescents are insufficiently active; the least active benefit most from modest increases.","url":"https://pubmed.ncbi.nlm.nih.gov/30418471/"},{"id":"momma2022","authors":"Momma H, Kawakami R, Honda T, Sawada SS","title":"Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies","journal":"British Journal of Sports Medicine","year":2022,"pmid":"35228201","doi":"10.1136/bjsports-2021-105061","type":"meta-analysis","finding":"Across 16 cohorts, muscle-strengthening activity carried 10 to 17 percent lower risk of all-cause mortality, cardiovascular disease, cancer and diabetes; all-cause RR 0.85 (263,058 participants); J-shaped dose curve with lowest RR 0.83 at 40 minutes a week and RR below 1.00 up to about 140 minutes; combined with aerobic activity RR 0.60; 13 of 16 studies self-reported; certainty rated very low.","url":"https://pubmed.ncbi.nlm.nih.gov/35228201/"},{"id":"shailendra2022","authors":"Shailendra P, Baldock KL, Li LSK, Bennie JA, Boyle T","title":"Resistance Training and Mortality Risk: A Systematic Review and Meta-Analysis","journal":"American Journal of Preventive Medicine","year":2022,"pmid":"35599175","doi":"10.1016/j.amepre.2022.03.020","type":"meta-analysis","finding":"Across 10 studies, any resistance training carried 15 percent lower all-cause (RR 0.85), 19 percent lower cardiovascular (0.81) and 14 percent lower cancer mortality (0.86); nonlinear dose-response with maximum 27 percent reduction at about 60 minutes a week (0.74), diminishing at higher volumes.","url":"https://pubmed.ncbi.nlm.nih.gov/35599175/"},{"id":"saeidifard2019","authors":"Saeidifard F, Medina-Inojosa JR, West CP, et al.","title":"The association of resistance training with mortality: A systematic review and meta-analysis","journal":"European Journal of Preventive Cardiology","year":2019,"pmid":"31104484","doi":"10.1177/2047487319850718","type":"meta-analysis","finding":"Across 11 studies (one trial, 10 cohorts) with 370,256 participants followed a mean 8.85 years, resistance training carried a hazard ratio of 0.79 for all-cause mortality alone and 0.60 combined with aerobic exercise; borderline for cardiovascular mortality (0.83), not significant for cancer mortality.","url":"https://pubmed.ncbi.nlm.nih.gov/31104484/"},{"id":"leong2015","authors":"Leong DP, Teo KK, Rangarajan S, et al.; PURE Study investigators","title":"Prognostic value of grip strength: findings from the Prospective Urban Rural Epidemiology (PURE) study","journal":"Lancet","year":2015,"pmid":"25982160","doi":"10.1016/S0140-6736(14)62000-6","type":"cohort","finding":"In 139,691 adults in 17 countries followed a median 4.0 years, each 5 kg lower grip strength carried a hazard ratio of 1.16 for all-cause mortality, 1.17 for cardiovascular mortality, 1.07 for myocardial infarction and 1.09 for stroke; grip predicted death better than systolic blood pressure; no association with incident diabetes, falls or fracture.","url":"https://pubmed.ncbi.nlm.nih.gov/25982160/"},{"id":"celismorales2018","authors":"Celis-Morales CA, Welsh P, Lyall DM, et al.","title":"Associations of grip strength with cardiovascular, respiratory, and cancer outcomes and all cause mortality: prospective cohort study of half a million UK Biobank participants","journal":"BMJ","year":2018,"pmid":"29739772","doi":"10.1136/bmj.k1651","type":"cohort","finding":"In 502,293 adults aged 40 to 69 followed a mean 7.1 years (13,322 deaths), each 5 kg lower grip carried a hazard ratio of 1.20 (women) and 1.16 (men) for all-cause mortality and 1.19 and 1.22 for cardiovascular mortality; weakness defined as below 26 kg (men) and 16 kg (women); grip improved an office risk score's C index by 0.013.","url":"https://pubmed.ncbi.nlm.nih.gov/29739772/"},{"id":"cruzjentoft2019","authors":"Cruz-Jentoft AJ, Bahat G, Bauer J, et al.; Writing Group for the European Working Group on Sarcopenia in Older People 2 (EWGSOP2)","title":"Sarcopenia: revised European consensus on definition and diagnosis","journal":"Age and Ageing","year":2019,"pmid":"30312372","doi":"10.1093/ageing/afy169","type":"consensus","finding":"Sarcopenia is a muscle disease defined first by low muscle strength, confirmed by low muscle quantity or quality, and graded severe by poor physical performance; cut-offs grip strength below 27 kg (men) and 16 kg (women), or more than 15 seconds for five chair rises.","url":"https://pubmed.ncbi.nlm.nih.gov/30312372/"},{"id":"newman2006","authors":"Newman AB, Kupelian V, Visser M, et al.","title":"Strength, but not muscle mass, is associated with mortality in the health, aging and body composition study cohort","journal":"Journals of Gerontology Series A: Biological Sciences and Medical Sciences","year":2006,"pmid":"16456196","doi":"10.1093/gerona/61.1.72","type":"cohort","finding":"In 2,292 adults aged 70 to 79 with 286 deaths over 4.9 years, quadriceps strength carried a crude hazard ratio of 1.51 per standard deviation in men and 1.65 in women; muscle size by CT or DXA was not strongly related to mortality and did not explain the strength association; grip gave similar estimates.","url":"https://pubmed.ncbi.nlm.nih.gov/16456196/"},{"id":"srikanthan2014","authors":"Srikanthan P, Karlamangla AS","title":"Muscle mass index as a predictor of longevity in older adults","journal":"American Journal of Medicine","year":2014,"pmid":"24561114","doi":"10.1016/j.amjmed.2014.02.007","type":"cohort","finding":"Among 3,659 NHANES III adults aged 55 and over (65 for women), the top quarter of bioimpedance muscle mass index had an adjusted all-cause mortality risk ratio of 0.81 and hazard ratio of 0.80 against the bottom quarter, after excluding the underweight and deaths in the first two years.","url":"https://pubmed.ncbi.nlm.nih.gov/24561114/"},{"id":"umpierre2011","authors":"Umpierre D, Ribeiro PA, Kramer CK, et al.","title":"Physical activity advice only or structured exercise training and association with HbA1c levels in type 2 diabetes: a systematic review and meta-analysis","journal":"JAMA","year":2011,"pmid":"21540423","doi":"10.1001/jama.2011.576","type":"meta-analysis","finding":"Across 47 randomized trials (8,538 patients) structured resistance training lowered HbA1c by 0.57 percentage points, aerobic by 0.73 and combined by 0.51; programs over 150 minutes a week lowered it by 0.89 against 0.36 for 150 minutes or less.","url":"https://pubmed.ncbi.nlm.nih.gov/21540423/"},{"id":"strasser2010","authors":"Strasser B, Siebert U, Schobersberger W","title":"Resistance training in the treatment of the metabolic syndrome: a systematic review and meta-analysis of the effect of resistance training on metabolic clustering in patients with abnormal glucose metabolism","journal":"Sports Medicine","year":2010,"pmid":"20433212","doi":"10.2165/11531380-000000000-00000","type":"meta-analysis","finding":"Across 13 randomized trials in people with abnormal glucose regulation, resistance training lowered HbA1c by 0.48 percentage points, fat mass by 2.33 kg and systolic blood pressure by 6.19 mm Hg, with no significant effect on total, LDL or HDL cholesterol, triglycerides or diastolic pressure.","url":"https://pubmed.ncbi.nlm.nih.gov/20433212/"},{"id":"ibanez2005","authors":"Ibañez J, Izquierdo M, Argüelles I, et al.","title":"Twice-weekly progressive resistance training decreases abdominal fat and improves insulin sensitivity in older men with type 2 diabetes","journal":"Diabetes Care","year":2005,"pmid":"15735205","doi":"10.2337/diacare.28.3.662","type":"rct","finding":"In nine older men with type 2 diabetes, 16 weeks of twice-weekly progressive resistance training at 50 to 80 percent of one-repetition maximum, without diet change or weight loss, raised insulin sensitivity 46.3 percent, cut visceral fat 10.3 percent and lowered fasting glucose 7.1 percent (146.6 to 135.0 mg/dL).","url":"https://pubmed.ncbi.nlm.nih.gov/15735205/"},{"id":"watson2018","authors":"Watson SL, Weeks BK, Weis LJ, Harding AT, Horan SA, Beck BR","title":"High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial","journal":"Journal of Bone and Mineral Research","year":2018,"pmid":"28975661","doi":"10.1002/jbmr.3284","type":"rct","finding":"In 101 postmenopausal women with low bone mass (mean age 65), eight months of twice-weekly 30-minute supervised high-intensity resistance and impact training (five sets of five at over 85 percent of 1RM) raised lumbar spine density 2.9 percent against a 1.2 percent fall with low-intensity home exercise, held femoral neck density (0.3 against minus 1.9 percent), improved every functional measure, and produced one adverse event (a minor back spasm).","url":"https://pubmed.ncbi.nlm.nih.gov/28975661/"},{"id":"zhao2015","authors":"Zhao R, Zhao M, Xu Z","title":"The effects of differing resistance training modes on the preservation of bone mineral density in postmenopausal women: a meta-analysis","journal":"Osteoporosis International","year":2015,"pmid":"25603795","doi":"10.1007/s00198-015-3034-0","type":"meta-analysis","finding":"Across 24 trials in postmenopausal women, resistance training raised femoral neck (SMD 0.303) and lumbar spine density (0.311) overall; programs combining resistance with impact or weight-bearing work drove the effect (0.411 hip, 0.431 spine) while resistance-alone protocols produced nonsignificant positive effects.","url":"https://pubmed.ncbi.nlm.nih.gov/25603795/"},{"id":"cornelissen2013","authors":"Cornelissen VA, Smart NA","title":"Exercise training for blood pressure: a systematic review and meta-analysis","journal":"Journal of the American Heart Association","year":2013,"pmid":"23525435","doi":"10.1161/JAHA.112.004473","type":"meta-analysis","finding":"Across 93 randomized trials (5,223 participants; 29 dynamic resistance groups), dynamic resistance training lowered systolic pressure 1.8 mm Hg and diastolic 3.2, endurance training 3.5 and 2.5, and five isometric groups 10.9 and 6.2; the dynamic resistance effect was largest in prehypertensive participants (4.0 over 3.8).","url":"https://pubmed.ncbi.nlm.nih.gov/23525435/"},{"id":"ralston2017","authors":"Ralston GW, Kilgore L, Wyatt FB, Baker JS","title":"The Effect of Weekly Set Volume on Strength Gain: A Meta-Analysis","journal":"Sports Medicine","year":2017,"pmid":"28755103","doi":"10.1007/s40279-017-0762-7","type":"meta-analysis","finding":"Across nine studies and 61 treatment groups, high weekly set volumes produced greater strength gains than low volumes (effect size difference 0.18; low 0.82, high 1.01) and medium volumes marginally beat low (0.15), a graded dose-response.","url":"https://pubmed.ncbi.nlm.nih.gov/28755103/"},{"id":"schoenfeld2017","authors":"Schoenfeld BJ, Ogborn D, Krieger JW","title":"Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis","journal":"Journal of Sports Sciences","year":2017,"pmid":"27433992","doi":"10.1080/02640414.2016.1210197","type":"meta-analysis","finding":"Across 15 studies and 34 treatment groups, each additional weekly set was associated with a 0.37 percent greater gain in muscle size, and higher-volume groups gained 3.9 percent more than lower-volume groups; a graded dose-response for hypertrophy.","url":"https://pubmed.ncbi.nlm.nih.gov/27433992/"},{"id":"grgic2018","authors":"Grgic J, Schoenfeld BJ, Davies TB, Lazinica B, Krieger JW, Pedisic Z","title":"Effect of Resistance Training Frequency on Gains in Muscular Strength: A Systematic Review and Meta-Analysis","journal":"Sports Medicine","year":2018,"pmid":"29470825","doi":"10.1007/s40279-018-0872-x","type":"meta-analysis","finding":"Across 22 studies, strength gains rose with frequency (effect sizes 0.74, 0.82, 0.93 and 1.08 for 1, 2, 3 and 4 or more sessions a week) but the effect vanished when weekly volume was equated, and was not significant in middle-aged and older adults or in men; frequency matters as a vehicle for volume.","url":"https://pubmed.ncbi.nlm.nih.gov/29470825/"},{"id":"morton2018","authors":"Morton RW, Murphy KT, McKellar SR, et al.","title":"A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults","journal":"British Journal of Sports Medicine","year":2018,"pmid":"28698222","doi":"10.1136/bjsports-2017-097608","type":"meta-analysis","finding":"Across 49 randomized trials (1,863 participants), protein supplementation during resistance training added 2.49 kg to one-repetition-maximum strength and 0.30 kg to fat-free mass; the effect fell with age, rose with training experience, and intakes beyond about 1.6 g/kg/day (break point 1.62) added no further fat-free mass.","url":"https://pubmed.ncbi.nlm.nih.gov/28698222/"},{"id":"fiatarone1994","authors":"Fiatarone MA, O'Neill EF, Ryan ND, et al.","title":"Exercise training and nutritional supplementation for physical frailty in very elderly people","journal":"New England Journal of Medicine","year":1994,"pmid":"8190152","doi":"10.1056/NEJM199406233302501","type":"rct","finding":"In 100 frail nursing-home residents (mean age 87, range 72 to 98), 10 weeks of high-intensity progressive resistance training raised strength 113 percent against 3 percent, gait speed 11.8 percent against a 1.0 percent decline and stair-climbing power 28.4 percent against 3.6; a multinutrient supplement without exercise changed no primary outcome.","url":"https://pubmed.ncbi.nlm.nih.gov/8190152/"},{"id":"keogh2017","authors":"Keogh JW, Winwood PW","title":"The Epidemiology of Injuries Across the Weight-Training Sports","journal":"Sports Medicine","year":2017,"pmid":"27328853","doi":"10.1007/s40279-016-0575-0","type":"review","finding":"Across 20 studies of weightlifting, powerlifting, bodybuilding, strongman, Highland Games and CrossFit, injury rates were relatively low compared with team sports (bodybuilding 0.24 to 1 per 1,000 hours; strongman 4.5 to 6.1; Highland Games 7.5), concentrated in shoulder, lower back, knee, elbow and wrist, with strains, tendinitis and sprains most common; most studies retrospective.","url":"https://pubmed.ncbi.nlm.nih.gov/27328853/"},{"id":"aasa2017","authors":"Aasa U, Svartholm I, Andersson F, Berglund L","title":"Injuries among weightlifters and powerlifters: a systematic review","journal":"British Journal of Sports Medicine","year":2017,"pmid":"27707741","doi":"10.1136/bjsports-2016-096037","type":"review","finding":"Across nine studies, injury incidence was 2.4 to 3.3 per 1,000 training hours in weightlifting and 1.0 to 4.4 in powerlifting, most often spine, shoulder and knee; similar to other non-contact strength and power sports and low compared with contact sports; most studies of low methodological quality.","url":"https://pubmed.ncbi.nlm.nih.gov/27707741/"},{"id":"pettersson2008","authors":"Pettersson J, Hindorf U, Persson P, et al.","title":"Muscular exercise can cause highly pathological liver function tests in healthy men","journal":"British Journal of Clinical Pharmacology","year":2008,"pmid":"17764474","doi":"10.1111/j.1365-2125.2007.03001.x","type":"rct","finding":"In 15 healthy men, one hour of weightlifting raised AST, ALT, lactate dehydrogenase, creatine kinase and myoglobin significantly for at least 7 days, while bilirubin, GGT and alkaline phosphatase stayed within the normal range.","url":"https://pubmed.ncbi.nlm.nih.gov/17764474/"},{"id":"baxmann2008","authors":"Baxmann AC, Ahmed MS, Marques NC, et al.","title":"Influence of muscle mass and physical activity on serum and urinary creatinine and serum cystatin C","journal":"Clinical Journal of the American Society of Nephrology","year":2008,"pmid":"18235143","doi":"10.2215/CJN.02870707","type":"cross-sectional","finding":"Among 170 healthy adults, those with moderate or intense physical activity had higher lean mass (55.3 against 48.5 percent) and higher serum creatinine (1.04 against 0.95 mg/dL) while cystatin C did not differ; lean mass remained related to creatinine but not cystatin after adjustment for protein and meat intake and activity.","url":"https://pubmed.ncbi.nlm.nih.gov/18235143/"},{"id":"pedersen2012","authors":"Pedersen BK, Febbraio MA","title":"Muscles, exercise and obesity: skeletal muscle as a secretory organ","journal":"Nature Reviews Endocrinology","year":2012,"pmid":"22473333","doi":"10.1038/nrendo.2012.49","type":"review","finding":"Skeletal muscle is a secretory organ whose several hundred secreted peptides, the myokines, communicate with fat, liver, pancreas, bone and brain; many depend on contraction, so inactivity probably alters the myokine response, a proposed mechanism linking sedentary behavior to chronic disease.","url":"https://pubmed.ncbi.nlm.nih.gov/22473333/"},{"id":"wolfe2006","authors":"Wolfe RR","title":"The underappreciated role of muscle in health and disease","journal":"American Journal of Clinical Nutrition","year":2006,"pmid":"16960159","doi":"10.1093/ajcn/84.3.475","type":"review","finding":"Muscle is the principal reservoir of amino acids that maintains protein synthesis in vital organs when nothing is absorbed from the gut and supplies the liver's gluconeogenic precursors; altered muscle metabolism is central to many chronic diseases, yet muscle mass, strength and metabolic function are rarely targeted as endpoints of dietary recommendations.","url":"https://pubmed.ncbi.nlm.nih.gov/16960159/"},{"id":"defronzo1985","authors":"DeFronzo RA, Gunnarsson R, Björkman O, Olsson M, Wahren J","title":"Effects of insulin on peripheral and splanchnic glucose metabolism in noninsulin-dependent (type II) diabetes mellitus","journal":"Journal of Clinical Investigation","year":1985,"pmid":"3894418","doi":"10.1172/JCI111938","type":"cross-sectional","finding":"Under a euglycemic insulin clamp, about 90 percent of infused glucose in controls and 87 percent in type 2 diabetes was disposed of by peripheral tissues, essentially muscle; leg glucose uptake was 45 percent lower in diabetes, making muscle the most important site of insulin resistance.","url":"https://pubmed.ncbi.nlm.nih.gov/3894418/"},{"id":"raichlen2017","authors":"Raichlen DA, Pontzer H, Harris JA, et al.","title":"Physical activity patterns and biomarkers of cardiovascular disease risk in hunter-gatherers","journal":"American Journal of Human Biology","year":2017,"pmid":"27723159","doi":"10.1002/ajhb.22919","type":"cross-sectional","finding":"Forty-six Hadza adults wearing heart-rate monitors averaged 134.92 minutes a day of moderate-to-vigorous activity, over 14 times that of US epidemiological study participants, maintained across the lifespan, with a low prevalence of hypertension among 198 measured and favorable cardiovascular biomarkers.","url":"https://pubmed.ncbi.nlm.nih.gov/27723159/"},{"id":"raichlen2020","authors":"Raichlen DA, Pontzer H, Zderic TW, et al.","title":"Sitting, squatting, and the evolutionary biology of human inactivity","journal":"Proceedings of the National Academy of Sciences of the United States of America","year":2020,"pmid":"32152112","doi":"10.1073/pnas.1911868117","type":"cross-sectional","finding":"Hadza adults were non-ambulatory for a mean 9.90 hours a day, as much as industrialized populations, but often in squatting and kneeling postures that demand more lower-limb muscle activity than chair sitting; the authors propose an inactivity mismatch hypothesis: human physiology is adapted to more consistently active muscles.","url":"https://pubmed.ncbi.nlm.nih.gov/32152112/"},{"id":"lieberman2015","authors":"Lieberman DE","title":"Is Exercise Really Medicine? An Evolutionary Perspective","journal":"Current Sports Medicine Reports","year":2015,"pmid":"26166056","doi":"10.1249/JSR.0000000000000168","type":"review","finding":"Humans evolved for regular moderate physical activity into late age but were also selected to avoid unnecessary exertion; most organ systems require the stimulus of activity to adjust capacity to demand, and selection never operated on the long-term effects of chronic inactivity (the exercise paradox); there is no evolutionarily determined optimal dose.","url":"https://pubmed.ncbi.nlm.nih.gov/26166056/"},{"id":"westcott2012","authors":"Westcott WL","title":"Resistance training is medicine: effects of strength training on health","journal":"Current Sports Medicine Reports","year":2012,"pmid":"22777332","doi":"10.1249/JSR.0b013e31825dabb8","type":"review","finding":"Narrative review estimating that inactive adults lose 3 to 8 percent of muscle mass a decade with a fall in resting metabolic rate, and that 10 weeks of resistance training may add 1.4 kg of lean weight, raise resting metabolic rate 7 percent and reduce fat weight 1.8 kg, with 1 to 3 percent gains in bone density.","url":"https://pubmed.ncbi.nlm.nih.gov/22777332/"}],"written":"2026-10-10","updated":"2026-10-10","reviewed":true,"reviewedOn":"2026-10-12","related":{"essays":["exercise-and-mitochondrial-health","movement-patterns-of-early-humans-lessons-for-fitness-today","exercise-as-an-epigenetic-modifier","mitochondrial-health-and-aging"],"glossary":["Mitochondria","VO2 max","DEXA scan","Insulin resistance"],"symptoms":["weight-loss-resistance","athletic-recovery","fatigue"],"entries":["fasting-insulin","homa-ir","hba1c","triglycerides","egfr","alt","vitamin-d","testosterone-men"]},"url":"https://taggehealth.com/labs/resistance-training","author":"Daniel Tagge, MD","publisher":"Tagge Health","license":"Free to read and cite with attribution to the URL above."}