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1. Hormonespreliminary · human dataAdded 8 August 2026

   The post-workout testosterone spike depends on how you measure it

   A meta-analysis of 21 studies found salivary testosterone and cortisol generally rise after acute aerobic, resistance and power exercise in men, but the size of the response varied heavily with study design and when baseline samples were taken, and the authors judged the overall evidence weak.

   ⚠What it shows: Only 2 of the 21 included studies were randomised controlled trials and 18 were uncontrolled; effect sizes differed sharply by design and baseline sampling time, and the authors call for standardised salivary hormone methodology.Meta-analysis · Sports Med

   Full breakdown →Cortisol explained →Recovery Readiness Index →Exercise-induced responses in salivary testosterone, cortisol, and their ratios in men: a meta-analysis. Sports Med 2015
2. Women's Healthpreliminary · human dataAdded 8 August 2026

   Intermittent fasting linked to 4.25 kg weight loss in PCOS

   In a meta-analysis of five studies, intermittent fasting reduced body weight by an average of 4.25 kg in women with PCOS, alongside improvements in BMI, insulin resistance, triglycerides, free androgens and inflammation, though total testosterone, cholesterol and waist-to-hip ratio did not change.

   ⚠What it shows: Meta-analysis of only five studies; the authors themselves describe the evidence as preliminary, and several hormone and lipid outcomes (total testosterone, cholesterol, AMH) showed no significant change.Meta-analysis · Nutrients

   Full breakdown →Insulin sensitivity explained →Calorie Deficit Calculator →Effect of Intermittent Fasting on Anthropometric Measurements, Metabolic Profile, and Hormones in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis. Nutrients 2025
3. Women's Healthwell supported · human dataAdded 8 August 2026

   Oestrogen-only HRT raises womb-lining risk, adding progestogen offsets it

   A Cochrane review of 45 randomised trials found oestrogen-only hormone therapy increases the risk of endometrial hyperplasia at all doses in postmenopausal women, while regimens combining low-dose oestrogen continuously with at least 1 mg norethisterone acetate or 1.5 mg medroxyprogesterone acetate carried no greater risk than placebo.

   ⚠What it shows: 2009 Cochrane review (a later update exists); applies to postmenopausal women with an intact uterus, and small study numbers plus clinical heterogeneity prevented meta-analysis for many outcomes.Meta-analysis · Cochrane Database Syst Rev

   Full breakdown →Hormone therapy in postmenopausal women and risk of endometrial hyperplasia. Cochrane Database Syst Rev 2009
4. Women's Healthwell supported · human dataAdded 8 August 2026

   PCOS linked to lower heart rate variability

   Women with PCOS show significantly lower heart rate variability than women without the condition, according to a meta-analysis of 17 studies. The reduction appeared in normal-weight and overweight women with PCOS, but not in the obese subgroup.

   ⚠What it shows: Meta-analysis of 17 observational studies of mixed quality (low to high risk of bias) with substantial heterogeneity; this is an association between PCOS and lower HRV, not proof that PCOS causes autonomic dysfunction or cardiovascular events.Meta-analysis · Syst Rev

   Full breakdown →HRV explained →Exploring heart rate variability in polycystic ovary syndrome: implications for cardiovascular health: a systematic review and meta-analysis. Syst Rev 2024
5. Women's Healthwell supported · human dataAdded 8 August 2026

   Laser therapy tops the rankings for genitourinary symptoms of menopause

   In a network meta-analysis of 29 randomised trials involving 8311 patients, laser therapy ranked as the most effective treatment for most genitourinary symptoms of menopause, followed by vaginal oestrogen, with both posing relatively low risk of adverse events. Ospemifene was superior for sexual function but carried a higher risk of adverse events and endometrial hyperplasia.

   ⚠What it shows: Bayesian network meta-analysis of 29 RCTs (8311 women); rankings rest on indirect comparisons rather than head-to-head trials, treatment effect varied with age, and the analysis pooled five quite different regimens.Meta-analysis · Pharmacol Res

   Full breakdown →Efficacy and safety of current therapies for genitourinary syndrome of menopause: A Bayesian network analysis of 29 randomized trials and 8311 patients. Pharmacol Res 2021
6. Hormoneswell supported · human dataAdded 8 August 2026

   Low SHBG emerges as a telltale marker of PCOS

   Women with PCOS have significantly lower levels of sex hormone-binding globulin (SHBG) than women without the condition, according to a meta-analysis drawing on 62 studies. Therapeutic interventions improved SHBG levels in women with PCOS, which was linked to fewer PCOS-associated complications.

   ⚠What it shows: Meta-analysis of observational comparisons with very high heterogeneity between studies (I2 93.9%); shows an association, not causation, and SHBG is proposed as a candidate biomarker rather than a stand-alone diagnostic test.Meta-analysis · Syst Biol Reprod Med

   Full breakdown →Sex hormone binding globulin - an important biomarker for predicting PCOS risk: A systematic review and meta-analysis. Syst Biol Reprod Med 2018
7. Cardiopreliminary · human dataAdded 6 August 2026

   Hot baths nudge the heart, but fitness proof is missing

   In a meta-analysis of 20 studies in healthy adults, a single hot-water immersion session raised heart rate by 28 bpm and lowered diastolic blood pressure by 5 mmHg, while repeated immersion reduced resting heart rate by 3 bpm. Only one study reported cardiorespiratory fitness data, and the authors call the overall cardiovascular benefits inconclusive.

   ⚠What it shows: Meta-analysis of 20 studies in healthy adults; only one study measured cardiorespiratory fitness, other cardiovascular markers showed no significant effects, and the authors describe the benefits as inconclusive.Meta-analysis · Physiol Rep

   Full breakdown →Sauna Therapy →Heart Age Calculator →The effects of hot-water immersion on cardiovascular and cardiorespiratory health of healthy adults: A systematic review and meta-analysis. Physiol Rep 2026
8. Women's Healthwell supported · human dataAdded 6 August 2026

   Group dance improves heart and body markers in older women

   In a meta-analysis of 17 studies, plaza dancing, group aerobic dance performed to music in public spaces, significantly reduced body weight, BMI, body fat percentage, resting heart rate, systolic blood pressure, cholesterol and triglycerides in healthy women aged 45 and over, and improved vital capacity, with BMI benefits strongest in programmes of 12 weeks or less.

   ⚠What it shows: Meta-analysis of 17 studies in healthy middle-aged and older women, drawn heavily from Chinese databases; effect sizes were mostly small to moderate and the authors call for larger, long-term follow-up trials.Meta-analysis · Front Public Health

   Full breakdown →Zone 2 explained →Body Fat Calculator →Effects of plaza dancing on body composition and cardiopulmonary function in middle-aged and the aged healthy women: a systematic review and meta-analysis. Front Public Health 2025
9. Trainingwell supported · human dataAdded 6 August 2026

   Stopping training doesn't erase your gains overnight

   Across 86 randomised trials (n=5,670), many exercise-induced gains, including body mass, waist circumference and maximal oxygen uptake, remained better than baseline even after training stopped, with residual benefits fading in an outcome-specific, time-dependent way while muscle mass, resting heart rate and LDL cholesterol benefits did not persist.

   ⚠What it shows: Meta-analysis of 86 RCTs (n=5,670); residual effects varied widely by outcome and detraining duration, and several markers, resting heart rate, LDL cholesterol, muscle mass and lean body mass, were no longer significantly improved at any follow-up.Systematic review · Front Physiol

   Full breakdown →Deload explained →VO2max Calculator →The effects of detraining on body composition and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials. Front Physiol 2026
10. Sleeppreliminary · human dataAdded 6 August 2026

    Exercise may lift students' sleep quality, with caveats

    Structured exercise programmes reduced university students' Pittsburgh Sleep Quality Index scores by 2.43 points versus non-exercise controls in a meta-analysis of seven trials with 701 participants, but very low evidence certainty and heavy variation between studies temper the finding.

    ⚠What it shows: Meta-analysis of only 7 RCTs (701 university students) with very high heterogeneity (I²=91.7%); the 95% prediction interval crossed zero and GRADE certainty was very low to low, so the effect may not generalise.Meta-analysis · Front Public Health

    Full breakdown →Sleep Calculator →Exercise interventions to improve sleep quality in university students: a systematic review and meta-analysis of randomized controlled trials. Front Public Health 2026
11. Cardiopreliminary · human dataAdded 6 August 2026

    Exercise lifts aerobic fitness in raised blood pressure

    Across 15 randomised trials in people with prehypertension or hypertension, exercise significantly improved aerobic capacity (SMD 0.88; 95% CI 0.61-1.15), with multicomponent training showing the strongest effect.

    ⚠What it shows: Meta-analysis of 15 RCTs in adults with prehypertension or hypertension; protocols varied widely and the subgroup findings on programme length, session frequency, session duration, weekly minutes and supervision are labelled exploratory by the authors, not a prescription.Study · J Hypertens

    Full breakdown →VO₂max explained →VO2max Calculator →Effects of exercise on aerobic capacity in people with prehypertension or hypertension: a systematic review and meta-analysis of randomized controlled trials. J Hypertens 2026
12. Sleepwell supported · human dataAdded 6 August 2026

    A warm soak added sleep time, not better sleep scores

    A meta-analysis of ten randomised trials in healthy adults found warm-water immersion thermotherapy increased total sleep time (SMD 0.63) and sleep efficiency (SMD 0.64), but did not significantly change sleep latency or any Pittsburgh Sleep Quality Index score.

    ⚠What it shows: Meta-analysis of ten RCTs in healthy adults; both significant effects were borderline, water temperature, timing and immersion protocols differed between trials, and subjective sleep quality did not improve on any PSQI component.Meta-analysis · Int J Biometeorol

    Full breakdown →Sauna Therapy →Sleep Calculator →The effect of water immersion thermotherapy on sleep quality: a systematic review and meta-analysis of randomized controlled trials. Int J Biometeorol 2026
13. Metabolic & GLP-1preliminary · human dataAdded 6 August 2026

    Night-shift fasting hints at better post-meal glucose

    A systematic review found only four randomised trials of meal-timing changes in shift workers: nearly 11 hours of overnight fasting was linked to lower post-meal glucose and non-esterified fatty acid responses versus eating and snacking at night, while insulin resistance improved in just one trial and HDL-C changed in none.

    ⚠What it shows: Systematic review of only four RCTs in adult shift workers, with different fasting windows and short durations; the authors explicitly question the robustness and generalisability of these preliminary positive signals.Review · Nutr Health

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Cardiometabolic status among shift workers under meal time regulation: A systematic review of randomized controlled trials. Nutr Health 2026
14. Nutritionwell supported · human dataAdded 6 August 2026

    Whey plus lifting tops the sarcopenia rankings

    In a network meta-analysis of 235 randomised trials covering 20,980 untrained older adults, whey protein plus resistance training ranked as the most effective combination for muscle mass (SMD 1.29) and leg strength (SMD 1.16), while whey plus multicomponent training ranked highest for mobility tasks.

    ⚠What it shows: Network meta-analysis of 235 RCTs in untrained older adults, so most rankings rest on indirect comparisons; certainty was moderate for muscle mass and leg strength, effects were moderated by participant condition and protein dose, and findings may not transfer to already-trained people.Meta-analysis · Nutrients

    Full breakdown →Sarcopenia explained →Protein Intake Calculator →Explore the Optimal Treatment Regimen Across Combinations of Variate Protein Sources and Exercise Modalities and Its Associated Factors in Older Adults: A Network Meta-Analysis and Meta-Regression of Randomized Controlled Trials. Nutrients 2026
15. Trainingwell supported · human dataAdded 6 August 2026

    Resistance training cut CRP in older adults

    A meta-analysis of 18 randomised controlled trials in 539 adults aged 60 and over found resistance training reduced C-reactive protein (effect size -0.72), TNF-α (-0.56) and IL-10 (-3.34), and tended to reduce IL-6 (-0.59). The CRP reduction held across every subgroup, including age, training method, intensity, weekly frequency and programme duration.

    ⚠What it shows: Pooled data from 18 RCTs and 539 adults aged 60 and over, using blood markers rather than disease outcomes; protocols were heterogeneous and the anti-inflammatory cytokine IL-10 also fell, which complicates the story.Meta-analysis · Int J Environ Res Public Health

    Full breakdown →Effects of Resistance Training on C-Reactive Protein and Inflammatory Cytokines in Elderly Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Int J Environ Res Public Health 2022
16. Cardiowell supported · human dataAdded 6 August 2026

    HIIT led four exercise types on blood pressure

    In a dose-response network meta-analysis of 28 randomised trials (2084 adults with metabolic syndrome), aerobic exercise, combined aerobic-plus-resistance training, mind-body exercise and HIIT were all associated with lower systolic blood pressure, with HIIT at 690 metabolic equivalent minutes per week the most effective dose at -5.07 mmHg. Effects appeared larger in participants with hypertension and in programmes lasting 16 weeks or more.

    ⚠What it shows: Bayesian network meta-analysis of 28 trials in 2084 adults with metabolic syndrome (mean age 55, mean BMI 31.68); the best doses are modelled estimates with wide credible intervals, not head-to-head trial results, and the authors say the dose ranges still need validating.Meta-analysis · Maturitas

    Full breakdown →HIIT explained →Heart Rate Zone Calculator →Comparative efficacy of various exercise modalities on blood pressure in patients with metabolic syndrome: A systematic review and dose-response network meta-analysis of randomized controlled trials. Maturitas 2026
17. Metabolic & GLP-1well supported · human dataAdded 6 August 2026

    GLP-1 drugs shaved a few mmHg off blood pressure

    Pooling 30 randomised controlled trials with 37 072 overweight or obese patients, GLP-1 receptor agonists lowered systolic blood pressure by 3.37 mmHg and diastolic by 1.05 mmHg compared with placebo. The effect was consistent across diabetes status, drug formulation, follow-up duration and route of administration, with the exception of exenatide subgroups.

    ⚠What it shows: Meta-analysis of 30 RCTs in 37 072 overweight or obese patients, but blood pressure was a secondary outcome in most of them and the absolute reductions are modest; these are prescription medicines whose use and monitoring sit with a clinician.Meta-analysis · J Hypertens

    Full breakdown →Metabolic syndrome explained →Heart Age Calculator →Effects of glucagon-like peptide-1 receptor agonists on blood pressure in overweight or obese patients: a meta-analysis of randomized controlled trials. J Hypertens 2025
18. Nutritionwell supported · human dataAdded 6 August 2026

    Berries barely moved metabolic syndrome markers

    A meta-analysis of 14 randomised trials (327 intervention and 284 control participants with metabolic syndrome) found berry consumption raised HDL cholesterol by 1.771 mg/dL and left almost everything else unchanged: LDL-C, total cholesterol, triglycerides, leptin, BMI, waist circumference, blood pressure, TNF-α, IL-6, CRP, adiponectin, HbA1c, HOMA-IR, glucose and insulin were all unaffected overall.

    ⚠What it shows: Pooled data from 14 small trials in people with metabolic syndrome, using different berries, doses and durations; the HDL rise is tiny and of unclear clinical meaning, and the longer-duration and larger-study signals come from subgroup analyses that are exploratory.Meta-analysis · Int J Food Sci Nutr

    Full breakdown →Metabolic syndrome explained →Metabolic Fitness Index →Effects of berry consumption on cardiometabolic risk factors in patients with metabolic syndrome: a systematic review and meta-analysis of randomised controlled trials. Int J Food Sci Nutr 2025
19. Metabolic & GLP-1well supported · human dataAdded 6 August 2026

    GLP-1 lipid drop wasn't explained by weight loss

    A meta-analysis of placebo-controlled randomised trials found GLP-1 receptor agonists modestly reduced LDL cholesterol (mean difference -2.93 mg/dL) and cut total cholesterol by about 7 mg/dL, while triglycerides, VLDL-C and HDL-C did not change significantly. Meta-regression found weight change did not explain the LDL or total cholesterol reductions.

    ⚠What it shows: Meta-analysis of placebo-controlled RCTs with extremely high heterogeneity (I2 above 99% in the meta-regressions); the absolute lipid changes are small, most trials were not designed with lipids as the primary endpoint, and these are prescription medicines managed clinically.Meta-analysis · Curr Med Res Opin

    Full breakdown →ApoB explained →Heart Age Calculator →Glucagon-like peptide 1 receptor agonists modestly reduced low-density lipoprotein cholesterol and total cholesterol levels independent of weight reduction: a meta-analysis and meta-regression of placebo controlled randomized controlled trials. Curr Med Res Opin 2025
20. Mindwell supported · human dataAdded 6 August 2026

    Mind-body exercise tops the list for ageing brains

    A network meta-analysis of 61 randomised trials found that mind-body exercise, acutherapy, cognitive training, non-invasive brain stimulation, meditation and physical exercise all improved global cognition in older adults versus passive controls, with mind-body exercise showing the largest effect (SMD 1.384).

    ⚠What it shows: Network meta-analysis of 61 RCTs in older adults with and without mild cognitive impairment; confidence intervals were wide, no active intervention significantly beat another, and intervention methods varied across trials.Meta-analysis · Sci Rep

    Full breakdown →Comparative efficacy of seven nonpharmacological interventions on global cognition in older adults with and without mild cognitive impairment: a network meta-analysis of randomized controlled trials. Sci Rep 2024
21. Women's Healthwell supported · human dataAdded 6 August 2026

    Exercise linked to lighter mood through menopause

    A meta-analysis of 17 randomised trials found that leisure-time physical activity alleviated depressive symptoms in menopausal women (SMD −1.23), with results similar regardless of exercise intensity, form, duration or supervision.

    ⚠What it shows: Meta-analysis of 17 RCTs with wide confidence intervals suggesting heterogeneity across studies; depression was measured with varied scales, and the authors call for further high-quality trials to confirm the findings.Systematic review · Front Psychiatry

    Full breakdown →Effect of leisure-time physical activity on depression and depressive symptoms in menopausal women: a systematic review and meta-analysis of randomized controlled trials. Front Psychiatry 2024
22. Cardiopreliminary · human dataAdded 6 August 2026

    Twice-weekly HIIT may be the endurance sweet spot

    In a 6-week randomised trial of 45 physically active male university students, twice-weekly 4 × 4 min HIIT improved VO2max and time to exhaustion about as much as three weekly sessions, while once weekly produced only a small VO2max rise; completion rates were 100%, 93% and 80% for the 1-, 2- and 3-session groups.

    ⚠What it shows: One 6-week RCT, n=45 physically active male university students (15 per group); homogeneous sample and short intervention period, so the 'optimal frequency' conclusion needs testing in larger, more diverse groups.Study · Front Physiol

    Full breakdown →HIIT explained →VO2max Calculator →Study on the effects of 4 × 4 min high-intensity interval training frequency on cardiorespiratory function, metabolic indices, and exercise performance in male university students. Front Physiol 2026
23. Sleepwell supported · human dataAdded 6 August 2026

    An afternoon nap can boost athletes' endurance

    A meta-analysis of 12 randomised trials in 179 team-sport athletes found early-afternoon napping produced a large improvement in endurance and a moderate gain in agility versus no nap, with naps longer than 60 minutes showing the biggest effects.

    ⚠What it shows: Meta-analysis of 12 RCTs but only 179 athletes in total; findings apply after presumed normal night sleep, and effects on cognitive and technical performance remain uncertain.Systematic review · Front Physiol

    Full breakdown →Sleep Calculator →The effect of daytime napping on the athletic performance of team ball sports athletes: systematic review and meta-analysis. Front Physiol 2026
24. Women's Healthpreliminary · human dataAdded 6 August 2026

    No sign the pill blunts fitness in active women

    A meta-analysis of 29 studies in 726 physically active premenopausal women found combined oral contraceptive use made little to no difference to heart rate, respiratory measures, IL-6, BMI or metabolic markers compared with non-users, though the certainty of the evidence was low.

    ⚠What it shows: Meta-analysis of 29 studies (726 active women), but certainty was rated low across all outcomes due to small samples, high risk of bias and varied methods, reassuring, not definitive.Systematic review · Front Physiol

    Full breakdown →Effect of oral contraceptive use on cardiorespiratory and immune function in premenopausal women involved in exercise: a systematic review and meta-analysis. Front Physiol 2026

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