Study archive · page 7

Pooled results from 18 trials in 1,591 adults aged 50 and over with osteoporosis linked exercise, especially resistance training, to better health-related quality of life across both physical and mental domains. Programmes shorter than 20 weeks produced the most consistent benefits.

⚠What it shows: Promising with a wrinkle: pooled results from 18 trials in 1,591 older adults, and the clearest gains came from resistance training with moderate-certainty evidence. But when every trial was lumped together across their different questionnaires the overall effect washed out, so the headline benefit rests on smaller comparisons.Meta-analysis · PeerJ

Long-term taekwondo participation was linked with higher femoral and lumbar spine bone density in children, adolescents and young adults, and short trials of 8 to 16 weeks raised femoral neck density in children and adolescents by 0.14 g/cm2. Every included study carried a high or serious risk of bias.

⚠What it shows: Interesting but fragile: all 18 studies covering 820 people carried a high or serious risk of bias, and much of the long-term evidence compares practitioners with non-practitioners at a single point in time rather than testing training directly. Evidence in middle-aged and older adults is close to nonexistent.Review · Sports Health

Ranking nine strategies across 24 randomised controlled trials in 1,298 older adults with sarcopenic obesity, resistance training came out best for improving handgrip strength and reducing fat mass, while multicomponent training ranked highest for lowering BMI and percentage body fat. No intervention significantly improved skeletal muscle index.

⚠What it shows: As strong as this kind of comparison gets: results pooled from 24 trials in 1,298 older adults, ranked against each other in one network. The programmes varied widely and no approach clearly improved the muscle index itself, so the win is on strength and fat, not on rebuilding muscle.Meta-analysis · Front Public Health

In a randomised placebo-controlled trial of 32 healthy young adults, 8 weeks of resistance training with daily clenbuterol (80 μg) added 1.7 kg more lean mass and bigger strength gains (+6 kg bench press, +16 kg leg press) than placebo, but fat loss was no greater than placebo. After 16 weeks of detraining the lean mass and bench press advantages had disappeared, and retraining rebuilt muscle no faster in the prior clenbuterol group.

⚠What it shows: A rare well-run test of this drug, but it covered just 32 healthy young adults over 8 weeks, so it says nothing about long-term use or safety. The effects were also clearly stronger in the men than the women.Study · Sports Med

A review pooling the only randomised trials that paired a standardised ashwagandha extract with structured resistance training found hints of bigger bench press and lower-body strength gains than placebo, but both effects lost statistical significance under stricter analysis and the certainty of the evidence was rated low to very low. There was no dependable effect on body fat.

⚠What it shows: Treat the strength boost as a hint, not a fact: only three poolable trials in 161 healthy adults exist, every one with quality concerns, and the apparent benefits disappeared under stricter statistical checks. Each result also leaned on a single influential trial, so one more good study could change the picture entirely.Meta-analysis · Nutrients

Pooling 60 randomised trials that compared 14 supplement strategies in overweight and obese adults, synbiotics, curcumin, green tea extract and probiotics combined with omega-3 each lowered at least one inflammatory blood marker, while no supplement significantly reduced leptin.

⚠What it shows: As pooled evidence goes this is substantial, 60 trials in overweight and obese adults, but doses, durations and participants varied so much that nobody can say which product at what dose actually works. These are blood-marker changes, not proof anyone got healthier.Meta-analysis · Nutrients

Pooling 9 randomised controlled trials, long-term L-citrulline supplementation combined with exercise modestly reduced body fat and android fat mass compared with exercise alone, with no significant effect on body weight, BMI, gynoid fat mass or total lean mass.

⚠What it shows: Real but small: results pooled from 9 trials found modest reductions in body fat and belly-region fat, while weight, BMI and lean mass did not change at all. Effects this size are easy to lose in future trials, so hold the finding lightly.Meta-analysis · Complement Ther Med

In a systematic review of randomised trials, interactive digital rehabilitation may improve pain-related functioning and lower pain intensity at 6-8 weeks in knee osteoarthritis, though certainty was low. After knee replacement it may aid functioning but made little to no difference to pain.

⚠What it shows: Promising but thin: trials were small, ranging from 36 to 306 people, most followed people for 3 months or less, and reviewers rated the key evidence low certainty. Better studies could shrink or erase the benefit.Meta-analysis · J Med Internet Res

In pooled results from eight trials with 854 adults with nonspecific chronic low back pain, exercise on its own reduced fear of movement more than passive care or usual care, by more than the smallest amount patients would notice. Certainty in the evidence was rated low.

⚠What it shows: Encouraging but shaky: eight trials with 854 people pointed the same broad way, yet the studies disagreed with each other a great deal and the overall evidence was rated low certainty. The authors themselves call it a trend, not a consistent effect.Review · Eur Spine J

Exercise programmes cut the odds of long-term work disability by about a third compared with usual care in people with persistent non-specific low back pain, across pooled results from 23 randomised trials. No single type of exercise proved better than another.

⚠What it shows: Solid but slow-burn evidence: results pooled from 23 trials found exercise beat usual care only in the long term, with nothing significant in the short or medium term and no clear winner among exercise types. The search also stops at 2008, so this is a mature rather than fresh finding.Meta-analysis · J Rehabil Med

Pooling 22 randomised trials with 619 adults, high-intensity interval training reduced pulse wave velocity, a marker of arterial stiffness, by 0.10 m/s more than moderate-intensity continuous training.

⚠What it shows: Solid pooled evidence: 22 trials covering 619 adults point the same way. The honest sizing is that HIIT's edge over steady cardio was 0.10 m/s of pulse wave velocity, a small margin, and the review does not say how long the benefit lasts or who gains most.Meta-analysis · Arch Gerontol Geriatr

A Cochrane review pooling 58 trials in 2075 sedentary adults found HIIT raised VO2max by 5.98 mL/min/kg and trimmed waist circumference versus doing no exercise, but improved VO2max by only 1.39 mL/min/kg more than steady moderate cardio, with no clear differences between the two on blood pressure, waistline or triglycerides.

⚠What it shows: About as trustworthy as exercise evidence gets: a Cochrane sweep of all the studies on this, pooling 58 trials in 2075 sedentary adults, though every trial was small and every session was supervised. Certainty for the HIIT versus steady cardio comparison was rated low, so that small fitness edge could yet shrink or grow.Meta-analysis · Cochrane Database Syst Rev

In pooled comparisons of randomised trials in people with type 2 diabetes, mind-body exercise outperformed conventional exercise on several cardiometabolic markers: mindfulness-based training lowered HbA1c by 0.78 points and systolic blood pressure by 13.00 mmHg, though most comparisons were rated very low certainty.

⚠What it shows: Handle with care: although this pools randomised trials, the reviewers themselves rated most comparisons very low certainty because of bias inside the trials and disagreement between them. The trials were also short, so the strikingly large effects need confirming before anyone reshuffles their routine.Meta-analysis · BMC Cardiovasc Disord

An umbrella review covering 112 systematic reviews and 2332 randomised trials found all lifestyle approaches produced modest weight loss in adults with overweight or obesity, with combined diet and physical activity delivering the largest reduction beyond a year at 3.68 kg, and cardiometabolic benefits that were partly independent of the weight lost.

⚠What it shows: The broad picture is trustworthy, the exact numbers less so: 112 pooled reviews covering 2332 trials agreed that lifestyle change works modestly, but the reviews often disagreed with each other and 69% were rated low or critically low quality. The headline weight figure beyond a year rests on a single contributing review.Study · Obes Pillars

A sweep of nine studies in 1,235 outpatients found probiotic use was linked to a lower chance of developing COVID-19 after exposure and faster recovery from mild infection, with fewer whole-body symptoms. Older people and those with conditions such as metabolic disorders appeared to benefit most.

⚠What it shows: Promising rather than proven: a sweep of eight randomised trials plus one before-and-after study in 1,235 outpatients, with the evidence rated moderate certainty overall. Only four of the nine studies were judged well run, so the size of the benefit remains uncertain.Systematic review · Nutr Health

Pooling ten randomised controlled trials in 1,560 adults aged 60 and over, oral lactobacilli-based probiotics increased seroconversion rates to all three strains of the seasonal influenza vaccine compared with placebo, though the reviewers caution that further research is needed to be more certain.

⚠What it shows: Encouraging but not settled: ten trials in 1,560 people aged 60 and over pointed the same way, but several had enough missing data to raise bias concerns, and the authors themselves call for more research before anyone leans on this.Meta-analysis · Age Ageing

Across 23 randomised trials in 1,862 perinatal women, relaxation-style exercise ranked as the most effective type for improving sleep quality, with programmes of 4 weeks or less, done 1-2 times per week in 30-60 minute sessions, performing best.

⚠What it shows: Solid enough to take seriously: results pooled from 23 trials in 1,862 pregnant and postpartum women. The rankings rest on indirect comparisons between studies that differed a lot, so the winning recipe is a best guess rather than a fixed rule.Meta-analysis · BMC Pregnancy Childbirth

Pooled results from 22 randomised trials in 1648 women found that non-drug approaches, including cognitive behavioural therapy, exercise, acupuncture and acupressure, significantly improved sleep quality and reduced insomnia severity after natural menopause.

⚠What it shows: Solid ground: results pooled from 22 trials in 1648 women after natural menopause, and the findings held up when individual studies were removed. The trials tested very different approaches, so it cannot say which single option works best for whom.Meta-analysis · Maturitas

A sweep of all the qualitative research on the question finds adults aged 50 and over believe wearable activity trackers can improve their health, but their engagement is blocked by personal, technological and environmental barriers, from fiddly functionality and alarms to a lack of support. The authors call for age-friendly design and ongoing backing from health professionals.

⚠What it shows: This distils opinions, not outcomes: it pools 10 interview-based studies of adults aged 50 and over, so it can explain why trackers get abandoned but not prove that better design gets anyone moving more. Views were gathered up to January 2024, and devices have kept evolving since.Meta-analysis · JMIR Mhealth Uhealth

In pooled results from 29 trials with 3005 adults aged 60 and over, activity trackers and smartphone apps may increase physical activity by about 1113 steps per day in the short term compared with minimal intervention, but the single trials that followed people for 6, 12 and 24 months suggested the gains were not sustained.

⚠What it shows: A genuine short-term boost, but hold it loosely: the finding pools 29 trials in 3005 people aged 60 plus, and the researchers rated the certainty of the evidence as low. The handful of trials that kept following people to 6, 12 and 24 months found no sign the extra steps lasted.Meta-analysis · J Orthop Sports Phys Ther

Across 15 randomised trials with 3,507 adults, fully automated digital cognitive behavioural therapy for insomnia produced substantial reductions in insomnia severity and consistent improvements in falling asleep and sleep efficiency, with no robust differences between delivery platforms.

⚠What it shows: Strong evidence: 15 trials pooled across 3,507 adults, with consistent results and little disagreement left between studies once their differences were accounted for. Newer trials tended to show smaller effects and few studies were app-based, so comparisons between platforms remain tentative.Meta-analysis · Sleep Breath

A meta-analysis of 126 studies found depression is associated with blunted, not exaggerated, physiological responses to acute mental stress, driven mainly by smaller cardiac and blood-flow reactions. Heart rate variability and stress-hormone responses showed no significant link.

⚠What it shows: A real but small signal: pooled results from 126 studies tied current depression to slightly muted heart and circulation responses during lab stress tests. These are links rather than causes, so nobody can say whether the blunted response leads to depression or follows from it.Meta-analysis · Psychol Bull

Pooling 17 studies, sunscreen use showed no overall association with melanoma, but in populations living more than 40 degrees from the equator it was associated with 1.6 times the odds of melanoma, possibly because common formulations absorbed UVB almost completely while transmitting large quantities of UVA.

⚠What it shows: A provocative pattern, not proof: pooled results from 17 studies that followed people rather than testing sunscreen on them, spanning 1966 to 2007, and the studies disagreed with each other strongly. It cannot separate the sunscreen from the sun habits of the people who used it.Meta-analysis · Ann Epidemiol

A sweep of 29 randomised trials found that stress-targeting interventions, from psychobiotic supplements to diets and lifestyle programmes, produced no consistent gut microbiome signature, and improvements in stress did not reliably move in parallel with microbiome changes.

⚠What it shows: The absence of a pattern carries weight because this was a sweep of all 29 randomised trials on the question. But those trials differed so much in people, products and measurement methods that the reviewers could only compare them narratively, so a real signal could still be hiding in the noise.Systematic review · Nutrients