Peer-reviewed research concerning metabolic, summarized and appraised in plain language with every source cited.
This study looked at how a lifetime of endurance exercise affects heart health and muscle strength in older men. It followed 59 men, average age 67, who had been doing…
This study set out to compare how different types of exercise affect muscle metabolism and insulin sensitivity in the short term. Twelve healthy young men did three sessions: sprint intervals…
This study looked at whether vitamin D changes how well metformin (a common diabetes drug that lowers blood sugar) can bring down prolactin (a pituitary hormone that suppresses testosterone when…
This study looked at whether a man's TyG index tracks with his risk of low testosterone as he ages. The TyG index is a simple score figured from fasting blood…
This study looked at whether a quick, low-effort high-intensity interval training routine (REHIT) could improve blood sugar control after meals and over a full day in healthy, active middle-aged men.…
This study set out to see if moderate-intensity walking could improve glucose tolerance after a night of partial sleep restriction, as high-intensity exercise has been shown to do. Eleven healthy,…
This study set out to see how swapping some animal protein for plant protein affects gut bacteria and tryptophan processing in men at risk for heart and metabolic problems. It…
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…
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…
This study looked at whether vitamin D levels are linked to metabolic health, measured by the TyG index (a score from fasting blood sugar and triglycerides that flags insulin resistance,…
This study looked at whether adding avocado and mango to the diet improves blood vessel function and metabolic health in adults with prediabetes. It was a randomized trial where 82…
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…
This study looked at whether the quality and amount of carbohydrates in a man's diet affect sperm DNA damage, a common problem in unexplained infertility. Researchers compared 300 Iranian men…
This systematic review and meta-analysis looked at how combining aerobic exercise with other interventions affects metabolic, heart, and inflammation markers in men. It pooled data from 14 randomized controlled trials…
This study looked at what drives low testosterone in U.S. men, going beyond aging to include habits and life circumstances. It analyzed over 10,000 men aged 18 and up from…
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…
This study compared two forms of omega-3 supplements, structured triglycerides (STGs) and physical mixtures (PMs), to see which better boosts blood EPA levels and muscle performance. Twenty-eight healthy young men…
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…
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…
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…
This study looked at how eating patterns relate to sperm quality in healthy young men. Researchers scored the diets of 200 men against several patterns, healthy ones like the Mediterranean…
This study looked at whether dietary polyphenols (plant antioxidants found in fruits, vegetables, tea, and olive oil) are linked to semen quality in young men. It analyzed 3-day diet records…
This study looked at how lifestyle and hormones affect semen quality and sperm DNA health in men. It examined 278 Indian men aged 21 to 50, measuring sperm count, movement,…
This study looked at how diet relates to sperm quality, comparing the Mediterranean diet, which is built on seasonal, fresh and whole foods, against ultra-processed foods, which are high in…
This study tested whether a workplace canteen could improve the health of men with metabolic syndrome (a cluster of a large waist, high blood pressure, high blood sugar, high triglycerides,…
This study set out to see whether ashwagandha, a herb widely sold for stress and performance, adds anything to interval training. Interval training here meant repeated hard efforts on a…
This study set out to see how lifestyle and insulin resistance relate to male fertility. Insulin resistance means the body has stopped responding properly to insulin, so it takes more…
This study set out to examine how cigarette smoking affects semen quality, hormone levels, metabolic health, zinc levels, and sperm DNA damage in young Russian men. It compared 450 smokers…
This study set out to see whether testosterone in men varies with the season, independently of age, weight and existing illness. It used the medical records of 27,328 Israeli men…
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…
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,…
This study set out to test whether the benefits of intermittent fasting come only from losing weight. Men with prediabetes ate all their meals inside a 6 hour window early…
This study set out to test whether vitamin D supplements raise testosterone in healthy men. It randomly assigned 98 men with normal testosterone but low vitamin D to a high…
This study looked at whether catching up on sleep at the weekend improves insulin sensitivity and hormones in men who habitually sleep too little in the week. Nineteen such men…
This study set out to see how cutting sleep affects glucose handling and hormones in young men. Fourteen healthy men were kept in a laboratory for two nights of 10…