The IOC consensus names the few supplements with good evidence; a 2026 systematic review of 44 contamination studies says how often a tub contains something the label does not mention.

A systematic review of 16 studies plus three recent case series show what a stage diet actually does to fat, lean mass, hormones and the menstrual cycle - and why the leanest competitor did not place highest.

The rationale behind post-workout protein and carbohydrate is real physiology. Two meta-analyses, one from 2013 and one from 2025, show the clock stops mattering once the daily total is right. Here are the numbers and the one narrow exception.

Every US guideline since 1980 said the same thing about plants, whole grains, saturated fat, sugar and salt. Here is why each edition was attacked anyway, and the two numerical contradictions 19 journal editors found in the newest one.

An anti-inflammatory diet is less a diet than a pattern: mostly plants, healthy fats, fibre, fish and steady blood sugar, with processed food kept to the margins. Here is what defines it and what the evidence says it does to inflammatory markers.

Skinfold calipers can track body composition well, but only when the site is marked exactly, the same technique is repeated every time, and the tester knows their own error. Here is what the research says about doing it properly.

Adults need 55 micrograms a day and most get twice that from food. The reference numbers, the Brazil-nut trap, and the meta-analysis linking extra selenium to higher diabetes risk.

Adults need 2,600 to 3,400 milligrams a day and average less. The reference numbers, the best food sources, and the trial analysis suggesting potassium does most of the work in salt-substitute blood pressure benefits.

Salmon, herring, sardines and mackerel carry most of the EPA and DHA on the fish counter. The reference tables per serving, and what the feed data say about farmed versus wild.

Beta-alanine buffers the acid that builds in hard one-to-four-minute efforts. A 40-study meta-analysis and a 2024 analysis of trained men put a number on how much that is worth - and for which events it is worth nothing.

Does a protein shake build more muscle? A 49-trial meta-analysis of 1,863 lifters puts the answer at 0.3 kg of lean mass and 2.5 kg on a 1RM - with a ceiling around 1.6 g/kg/day and a bigger payoff the more trained you are.

HMB is sold as a muscle-sparing anabolic. The mechanism is real in rats; in trained humans the pooled effect on strength is 1.1 kg with a confidence interval that crosses zero. Here is what the trials found, and why two of the famous ones were excluded.

Low-carb, low-fat, high-protein, Mediterranean: which loses more? Five landmark trials, the two-year DIRECT study, a 609-person head-to-head and a 121-trial network meta-analysis agree on the number - and on where the ratio still matters.

L-carnitine is sold for fat burning and recovery. The muscle does not absorb it from a capsule, the fat-loss effect is about a kilogram, and the recovery signal comes from 79 people in seven trials - most from one lab. The numbers, and who paid for them.

Beetroot juice lowers the oxygen cost of exercise and extends time to exhaustion by about 25 seconds. It does not make time trials faster. A 2025 umbrella review of 20 meta-analyses and 2,672 participants shows where the line falls.

Citrulline is in every pre-workout for its nitric-oxide promise. One elegant 10-man trial showed why; two meta-analyses of 30 and 6 trials show how small the effect is - g = 0.16 overall, and nothing for endurance time trials.

Fish oil is the anti-inflammatory everyone takes and few can measure. The pooled trials show soreness drops by less than a point on a 10-point scale, performance does not change, and the newest position stand is more confident than its data.

More than half of athletes test low for vitamin D. Whether topping it up makes them stronger is a different question - and an 11-trial meta-analysis of 436 athletes says the pooled strength effect is not distinguishable from zero.

Taurine is in every energy drink and most pre-workouts. A 10-study meta-analysis found a moderate boost to time to exhaustion from a single 1 to 6 g dose; a 15-study follow-up found the same for jumps and nothing for VO2max. Small trials, real signal.

Glutamine was the recovery supplement of the 1990s. A 25-trial meta-analysis found no effect on aerobic performance, lean mass or immune cells - and a small weight loss nobody asked for. Here is what a decade of trials actually measured.