Health science reports2026n = 30
RCTHuman
This study compared how two types of high-intensity exercise affect hunger hormones, appetite, and body composition in overweight and obese men. Thirty men were split into groups doing either running-based…
2026n = 10,027 men in population studies, 51 men in clinical trial
OtherHuman
This study built a better way to read testosterone in men, especially men with obesity, by accounting for SHBG (sex hormone-binding globulin, a protein that binds testosterone and sets how…
Obesity (Silver Spring, Md.)2026n = 17
RCTHuman
This study set out to see if cutting protein while keeping calories the same could help men with overweight or obesity lose weight. Seventeen men were randomly assigned to eat…
Journal of cachexia, sarcopenia and muscle2026n = 68 (37 HIIT + L-citrulline, 31 HIIT + placebo)
RCTHuman
This study looked at how high-intensity interval training (HIIT), where short bursts of hard effort alternate with easier recovery periods, with or without L-citrulline (an amino acid that may boost…
Journal of obesity2026n = 20
RCTHuman
This study tested whether pairing intermittent fasting with weightlifting improves body composition in obese men. It randomly assigned 20 obese men aged 20 to 30 to either a normal diet…
The journal of sexual medicine2026n = 639 men across 10 studies
Systematic ReviewHuman
This systematic review set out to assess how GLP-1 receptor agonists (a class of diabetes and weight-loss drugs) affect male reproductive hormones, semen quality, and metabolic health. It pooled data…
Human reproduction update2026n = 32 studies included
Meta AnalysisHuman
This study set out to review how different weight loss methods affect male fertility in men with obesity. It looked at 32 studies that compared lifestyle changes, medications, and bariatric…
Scientific reports2026n = 34
RCTHuman
This study compared two exercise approaches, high-intensity functional training (HIFT) and traditional resistance training (RT), for improving metabolic, inflammatory, and physical health in overweight men. Thirty-four men with an average…
American journal of men's health2026n = 7,418
Cross SectionalHuman
This study set out to explore how obesity and chronic inflammation relate to testosterone levels in men. It analyzed data from over 7,400 adult men in the US, using body…
Asian journal of andrology2026n = 3336
Cross SectionalHuman
This study set out to examine how modifiable lifestyle factors like smoking, drinking, and weight affect semen quality in men. It analyzed data from over 3,300 men visiting a fertility…
Journal of endocrinological investigation2026
Narrative ReviewHuman
This review looked at how aging affects men's hormones, sleep, and metabolism, centering on two kinds of hypogonadism (when the testicles do not make enough testosterone, causing symptoms like low…
Nutrients2026n = 28 participants
OtherHuman
This study set out to compare how men and women respond to a 12-week Mediterranean-style weight-loss diet, focusing on changes in body fat, eating habits, and mental health. It followed…
Frontiers in public health2026
Meta AnalysisHuman
This study compared two approaches to resistance training, linear periodization (a steady progression of weight up and reps down over months) and undulating periodization (varying weight and reps week to…
Quantitative imaging in medicine and surgery2026n = 36
Cross SectionalHuman
This study looked at how a man's testosterone and SHBG relate to where his body stores fat. SHBG, or sex hormone-binding globulin, is a protein that binds testosterone and sets…
Asian journal of andrology2026n = 43 studies included
Systematic ReviewHuman
This umbrella review (a review of other reviews) set out to catalogue what damages male fertility. It gathered 43 systematic reviews and meta-analyses published between 2000 and 2025, covering 67…
Cureus2026n = 100
Cross SectionalHuman
This study looked at how different measures of obesity relate to semen quality in men from infertile couples who had no other known fertility risks. It compared body mass index…
Cureus2026
Narrative ReviewHuman
This is a narrative review (an expert summary of existing research, not a new experiment) asking whether testosterone replacement therapy (TRT) could help men with low testosterone hold onto muscle…
Current opinion in urology2025
Narrative ReviewHuman
This review gathers recent evidence on what damages male fertility and how much of it can be undone. Smoking raises sperm DNA fragmentation (breaks in the genetic material inside sperm)…
Reproductive biology and endocrinology : RB&E2025n = 2,430
Cross SectionalHuman
This study looked at whether obesity speeds up the decline in sperm quality that has been seen over time. Researchers reviewed semen tests from 2,430 men with normal sperm counts…
Frontiers in endocrinology2025n = 304
CohortHuman
This study looked at how different types of exercise affect body composition during weight loss. It compared resistance training, aerobic exercise, and no exercise in 304 adults on a calorie-restricted…
Frontiers in endocrinology2025n = 8,443 men (3,467 normal BMI, 3,444 overweight, 1,532 obese)
Meta AnalysisHuman
This meta-analysis (a study that statistically pools many earlier studies) looked at how body mass index (BMI, a weight-for-height number used to flag over- or under-weight) relates to sperm quality…
Andrology2024n = 1,774 participants across 44 studies
Meta AnalysisHuman
This meta-analysis set out to measure how much testosterone men with obesity get back when they lose weight, comparing low-calorie diets with bariatric surgery. It pooled 44 studies covering 1,774…
Journal of psychopharmacology (Oxford, England)2023
RCTHuman
This study set out to test whether ashwagandha, a traditional herb, could reduce stress and fatigue in overweight or mildly obese adults aged 40-75 who reported high stress and fatigue.…
Physiology & behavior2021n = 18
RCTHuman
This study set out to see how severe sleep restriction affects appetite, food intake, and appetite-regulating hormones in healthy young men. It compared three nights of very little sleep (2…
The American journal of clinical nutrition2020n = 16 (8 per group)
OtherHuman
This study set out to see whether two weeks of eating earlier in the day improves how muscle takes up sugar and amino acids. Sixteen healthy young men were put…
Obesity (Silver Spring, Md.)2019n = 15
RCTHuman
This study set out to see whether restricting the hours of the day a man eats improves how his body handles sugar. Fifteen men at risk of type 2 diabetes,…
Clinical endocrinology2018
Narrative ReviewHuman
This review looked at the link between obesity and low testosterone in men, focusing on how weight affects hormone levels and what treatments might help. It examined studies on men…
European journal of endocrinology2013n = 24 studies
Meta AnalysisHuman
This study set out to see how losing weight affects testosterone in men with obesity. It pooled 24 trials comparing low-calorie diets against bariatric surgery, measuring changes in total testosterone…
Circulation2011n = 14,345
CohortHuman
This study set out to see how changes in fitness and in body weight affect a man's risk of dying, from any cause and from heart disease. It followed 14,345…