In two small crossover studies of men, cuff occlusion applied before each explosive bench press or squat set kept power higher from the third set onwards; bar velocity was also higher in the bench press study.

After a fatiguing protocol, back-squat bar velocity fell at every load tested, and mean velocity at 40% or 80% of 1RM best matched losses in jump height. But warm-up-based 1RM predictions varied too much between individuals for daily load setting.

Quercetin, a plant flavonoid, is marketed for recovery. In 12 and 16 men from one laboratory, 1,000 mg a day for 14 days raised isometric strength 4.7% from baseline and reduced the loss of strength and muscle fibre conduction velocity after damaging eccentric exercise.

A review of 19 studies found good sleepers ate a higher share of protein, but with no dose-response. In a three-day crossover trial, a high-carbohydrate diet improved sleep efficiency, sleep onset and melatonin compared with a high-protein, low-carbohydrate diet.

A scoping review found bedtime variability was linked to poorer diet quality but not to total calories. Studies of social jetlag in students point the same way, though all the evidence is observational.

A meta-analysis of three trials in 151 older adults found magnesium shortened sleep onset latency by 17.36 minutes versus placebo, on low to very low quality evidence. For exercise performance, most human data are cross-sectional or indirect.

In a placebo-controlled crossover trial, night-time melatonin did not change sleep, morning caffeine increased shuttle-run distance with or without melatonin, and the combination lowered muscle-damage and inflammation markers. Taken in the daytime, melatonin dulled alertness and memory without changing a 4-km time trial.

In two small crossover trials in trained men, foam rolling during the rest between sets did not hurt performance: it was linked to more repetitions on the leg extension and lat pull-down, lower soreness in one study and unchanged effort in the other.

Across 56 studies, self-reported well-being tracked training load more sensitively and consistently than common objective measures. After a simulated match, readiness questions on strength and soreness changed at 24 and 48 hours while jump tests did not.

A 2026 meta-analysis of 10 studies found palm or sole cooling between sets had no significant effect on training volume or perceived effort. One small study in trained women saw more volume, but heating worked about as well.

A 0–10 perceived recovery rating moderately tracked changes in sprint performance, fell sharply 48 hours after a high-volume lifting session, and showed excellent reliability after interval training. None of these studies tested whether training by it beats a fixed plan.

Adjusting training by daily HRV improved HRV itself, but its advantage for fitness and performance over a fixed plan was small or not significant in three meta-analyses of endurance training. After lifting, HRV recovered before neuromuscular markers did.

Sessions at 80% of 1RM to failure, and squat sets taken to 40% velocity loss, shifted HRV more than lighter or less fatiguing work, with differences detectable from 30 minutes to 24 hours. HRV reflects session strain, not proven readiness.

Caffeine is promoted as a soreness reliever. In 20 elite athletes it restored lost strength in both sexes but cut soreness by 21.5% in men versus 4.6% in women; pooled trials show a reduction at 48 hours, with a 24-hour reduction only in resistance-exercise studies.

In healthy volunteers, late chronotypes performed worse in the morning than early chronotypes on grip strength, vigilance and executive function. Long-term training effects were not tested.

In a survey of 156,696 Korean adults, higher sodium intake was associated with modestly higher odds of poor sleep quality, short sleep and waking to urinate, and a small student survey agreed. We found no trial testing whether cutting salt improves sleep.

In a crossover trial, two hours of smartphone use before bed for five nights worsened elite soccer players' sleep and next-day reaction time, jumping and agility. In a diary study, only multiple-device use was linked to harder sleep onset, and amber glasses improved only self-rated sleep.

Men with an estimated fast muscle typology lost more power during all-out sprints and had not recovered strength 5 hours later, while slow types recovered in 20 minutes. In novice lifters, typology partly explained repetitions to failure at 60% and 80% of 1RM.

Sets taken to failure, especially with many repetitions, reduced jump height and bar velocity for up to 48 hours. In the first hour, heavy and high-volume sessions did not differ in force, but high-volume work briefly impaired agility and memory.

In observational data, vitamin D deficiency was associated with higher odds of sleep disorders (OR 1.50, 95% CI 1.31 to 1.72). In a meta-analysis of three randomised trials, supplementation lowered the Pittsburgh Sleep Quality Index versus placebo (mean difference −2.33, 95% CI −3.09 to −1.57), with moderate certainty.