Study archive · page 21

Across 12 video-analysis studies covering 538 lower-limb muscle injuries in professional footballers, 74.7% involved the hamstring, and non-contact injuries during moderate-to-high speed actions were far more common than injuries involving contact.

⚠What it shows: A solid description of how these injuries happen, pooled from 12 video studies of 538 injuries in professional footballers, but nearly all the analysable data came from men. The studies also did not account for how much time players spent sprinting versus jogging, so the exact odds are shaky.Systematic review · Sports Med Open

A meta-analysis of 31 randomised trials in 785 people found that resistance training one limb increased strength in the opposite, untrained limb by 11.9% on average, with eccentric training producing the largest transfer at 17.7%.

⚠What it shows: Reasonably solid: results pooled from 31 randomised trials in 785 people agree the effect is real, though many of those trials had quality problems, so the exact size of the carry-over is less certain than the headline figure suggests.Meta-analysis · Eur J Appl Physiol

Across 24 randomised trials in 951 older adults diagnosed with sarcopenia, resistance training improved grip strength, gait speed, knee extension strength and sit-to-stand performance, but the average gains fell short of thresholds for a clinically meaningful difference, and muscle mass did not significantly change.

⚠What it shows: Trustworthy on direction, sobering on size: results pooled from 24 randomised trials in 951 older adults with diagnosed sarcopenia consistently show strength and function improving, yet most gains were too small to clear the bar researchers set for a benefit patients would actually notice. Muscle mass itself did not clearly change.Meta-analysis · Aging Clin Exp Res

In older adults, dance programmes matched conventional exercise for cardiorespiratory fitness and quality of life across 17 randomised trials, and pooled results showed a significant advantage for dance on muscle strength.

⚠What it shows: Encouraging but not the final word: results pooled from 17 trials in 1,881 older adults, nearly three quarters of them women, and the fitness comparisons disagreed with each other a lot. The large strength advantage for dance is the most striking finding and also the least settled one.Systematic review · Front Sports Act Living

Resistance training significantly reduced the inflammatory marker IL-6 in Asian adults with sarcopenia, according to pooled randomised trials. Other markers, including TNF-α, CRP and IL-10, did not change significantly.

⚠What it shows: Modest weight for now: results pooled from six trials with 278 Asian adults who already had sarcopenia, and only one of four inflammation markers actually fell. Whether the same holds in other populations, or translates into how people feel and function, is not yet known.Meta-analysis · Front Immunol

Exercise improved sleep quality and insomnia symptoms in perimenopausal women across 12 randomised trials of 1493 women, with fitness Qigong practised more than 3 times a week for 30 to 60 minutes over 10 to 12 weeks looking most effective.

⚠What it shows: Reasonably solid overall: results pooled from 12 trials in 1493 women showed a clear improvement in sleep. The best-format finding comes from smaller subgroup comparisons though, so treat the Qigong specifics as a lead worth following rather than a verdict.Meta-analysis · Explore (NY)

A network meta-analysis of 33 randomised trials in 3658 postmenopausal women found traditional Chinese exercises such as Taiji, Yijinjing and Baduanjin improved bone mineral density at the spine and hip, with exercise combined with medication ranking best of all.

⚠What it shows: Promising but not yet settled: results pooled from 33 trials in 3658 women point the same way, but many individual comparisons rest on few, small studies and the authors themselves say firmer trials are needed. Treat the rankings between practices as provisional.Meta-analysis · Front Endocrinol (Lausanne)

Pooled results from 13 randomised trials show that combining exercise with calcium and vitamin D supplementation increased bone mineral density at the lumbar spine and femoral neck in postmenopausal women, compared with the supplements alone. Whole-body vibration produced the most consistent benefits, and programmes of six months or less showed greater gains than longer ones.

⚠What it shows: Reasonably solid: results pooled from 13 trials in postmenopausal women point the same way at both the spine and the hip. The included studies varied a lot in design, and the odd finding that programmes over six months added nothing extra deserves confirming.Meta-analysis · Nutrients

Structured diet and physical activity programmes reduced postpartum weight retention by 2.19 kg on average in women with recent gestational diabetes, across pooled randomised trials. The first year after birth may be the key window.

⚠What it shows: Credible and useful: results pooled from 12 trials with 5,672 women who had recent gestational diabetes. Waist circumference did not clearly shrink, and the programmes varied in what they actually involved, so the average hides a mix of approaches.Meta-analysis · Obes Rev

A systematic review of 10 studies in people under 60 found intermittent fasting may reduce fat mass while at least maintaining muscle in resistance-trained and overweight individuals, alongside improvements in glucose and insulin levels.

⚠What it shows: Promising but thin: a sweep of all the studies on this found only 10, most of them small and all in people under 60, and the authors say the body composition picture is not yet settled. It also cannot say whether fasting beats ordinary dieting.Systematic review · Int J Food Sci Nutr

Across 29 randomised trials in 2,363 adults aged 50 and over, plant and animal protein produced similar effects on lean mass, handgrip strength and most blood markers; the one marginal difference favoured plant protein for total cholesterol.

⚠What it shows: Reasonably solid: results pooled from 29 trials in 2,363 adults aged 50 and over, and the two protein sources performed alike on almost everything measured. The catch is that most trials tested soy powder against dairy powder, so swapping whole foods like beans for beef was barely studied.Study · Clin Nutr ESPEN

Among 2,264 Finnish adults assessed at age 46, higher habitual coffee intake was associated with lower total and visceral fat and higher skeletal muscle mass despite similar BMI across groups. In men, each extra cup a day was linked to higher total testosterone and SHBG but lower free testosterone; women showed only the SHBG and free testosterone pattern.

⚠What it shows: Interesting but not proof: researchers measured 2,264 people at a single point in time, so coffee drinkers may simply differ in ways the analysis could not fully account for, even after adjusting for BMI, smoking, activity, education and alcohol. Nothing here shows coffee changed anyone's body or hormones.Study · Eur J Nutr

In older adults with mild cognitive impairment, aerobic exercise beat non-aerobic exercise for cardiorespiratory fitness, cognitive flexibility and delayed recall across a meta-analysis of 15 trials, but broad cognition scores on the MoCA and MMSE did not differ.

⚠What it shows: Reasonably solid but narrow: results pooled from 15 trials in 1,192 older adults with mild cognitive impairment showed gains on specific tests of speed and memory, while broad cognition scores did not move. Whether those test gains translate into everyday thinking is not answered here.Study · Ann Indian Acad Neurol

Across 40 randomised trials, structured exercise more than doubled the odds of remission from depression compared with no exercise, with 2.40 times the odds of remission and a number needed to treat of 2.1, though the trials varied widely and the benefit may not extend to every group.

⚠What it shows: Convincing for remission, shakier for symptom scores: results pooled from 40 trials where people were assigned at random, but only 12 were at low risk of bias and most lasted 16 weeks or less. The studies disagreed with each other enough that exercise may not help every group.Meta-analysis · J Vis Exp

Following 260 Finnish adolescents over 8 years, more self-reported screen time from childhood to adolescence was associated with faster reaction times and better accuracy on working memory tasks and with better overall cognition, while more cumulative unsupervised physical activity was associated with slightly worse working memory accuracy. The associations were all small.

⚠What it shows: Counterintuitive and far from settled: researchers followed 260 teenagers rather than testing anything on them, the activity and screen figures were self-reported, and the links found were small. It cannot tell you screens improved anyone's thinking.Study · Pediatr Exerc Sci

Across 159 randomised trials in 10,821 adults aged 45 and over, every exercise modality lowered resting blood pressure, with circuit-based training showing the largest estimated systolic drop of 13.52 mmHg. The modelled benefit peaked around a weekly dose of 1200 METs-minutes, the upper end of WHO activity guidance.

⚠What it shows: The big picture is trustworthy: exercise of any kind lowers blood pressure, based on results pooled from 159 trials in 10,821 middle-aged and older adults. The league table is far shakier; the authors rate the certainty of the comparisons low and warn that circuit training's top spot rests on limited evidence.Systematic review · Sports Med

Pooling 14 randomised trials in 1847 overweight and obese adults, 6-month aerobic exercise programmes reduced weight by just 1.6 kg on average and 12-month programmes by 1.7 kg, leading the authors to conclude that cardio alone is not an effective weight loss therapy.

⚠What it shows: Convincing on its own terms: results pooled from 14 trials in 1847 overweight and obese adults, all testing cardio with no diet change attached. It covers moderate steady exercise only, so harder training formats or cardio plus dieting could tell a different story.Meta-analysis · Am J Med

Across 155 randomised trials in 9,906 people, probiotic supplements modestly improved blood lipids: triglycerides fell by 10.83 mg/dL on average, total cholesterol by 8.46 mg/dL, LDL cholesterol by 5.83 mg/dL, and HDL cholesterol rose by 1.28 mg/dL.

⚠What it shows: Large and consistent: results pooled from 155 trials in 9,906 people all pointed the same way, so the effect looks real. It is also small, and the trials used many different strains and doses, so no single product can claim these numbers.Review · Crit Rev Food Sci Nutr

Isotope-tracing work found that two phenol compounds considered uremic toxins come from gut bacteria breaking down the body's own secreted proteins such as mucins, while the beneficial-looking phenols hippuric acid and 3-phenylpropionate come from dietary protein that resists digestion. Fibre reduced bacterial digestion of those host proteins and so suppressed the toxin-type phenols.

⚠What it shows: Mechanism work, not a diet result: it explains how fibre and hard-to-digest plant protein shift bacterial metabolites, but the abstract reports no health outcomes, so nobody has shown this changes how anyone feels or lives.Study · Proc Natl Acad Sci U S A

Curcumin supplementation reduced blood markers of exercise-induced muscle damage and eased delayed-onset muscle soreness in pooled randomised trials, lowering creatine kinase by 48.54 IU/L on average.

⚠What it shows: Reasonable evidence for a modest effect: results pooled from randomised trials in adults showed less soreness and lower muscle-damage markers after curcumin. Doses, exercise types and study lengths varied widely, so how much relief any one person would notice is uncertain.Meta-analysis · Phytother Res

Beef protein supplements matched whey for gains in lean mass and changes in fat mass across pooled randomised trials. Compared with no protein at all, beef protein increased daily protein intake, lean body mass and lower-limb strength.

⚠What it shows: Solid as far as it goes: results pooled from seven trials with 270 people found the protein source mattered less than getting enough of it. Fat mass and upper-body strength did not clearly improve over no supplement, so the benefits were specific rather than across the board.Meta-analysis · Nutrients

Adding protein supplements to resistance training improved walking speed in older adults more than training alone, across 18 randomised trials involving 1,147 people. The benefit was concentrated in those who took their protein after the training session.

⚠What it shows: Fairly strong with a wrinkle: results pooled from 18 trials in 1,147 older adults, but the trials disagreed with each other a good deal about how big the benefit was. The after-training timing finding comes from a subgroup comparison, so it is suggestive rather than settled.Meta-analysis · J Aging Phys Act

In an indirect comparison of matched Phase 3 trials, tirzepatide 10 mg and 15 mg produced 4% and 5.4% additional weight loss and a 0.4% larger HbA1c reduction than semaglutide 2.4 mg, with fewer gastrointestinal side effects; the two drugs have never been compared head to head.

⚠What it shows: Treat this as a strong hint, not a verdict: the two drugs have never been tested in the same trial, so researchers lined up results from separate large trials instead, a method that can mislead. Two of the authors have received speaker fees from the makers of both drugs.Systematic review · Diabetes Metab Syndr

A systematic review of 24 randomised trials found workplace exercise programmes, especially strength work targeting the neck, shoulders and upper limbs, reduced pain and helped prevent musculoskeletal disorders in workers.

⚠What it shows: Encouraging but broad-brush: a sweep of 24 trials where workers were assigned at random to exercise programmes or not, reported without pooled numbers, so the direction of the effect is clearer than its size. The programmes varied a lot between studies, which makes the ideal routine hard to pin down.Systematic review · Aten Primaria