Topic
Strength
Research on building maximal strength and performance — pre-workout supplements and intensity prescriptions.
Research
Related research
- Meta-analysisConfidence: Moderate2018
Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials
Sanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A, Sadarangani KP, Cristi-Montero C / Journal of Science and Medicine in Sport
Key point: HMBのトレーニング経験者・競技者への筋肉量増加効果は統計的に有意でないケースが多かった
- Randomized controlled trialConfidence: Moderate2018
Efficacy of ketogenic diet on body composition during resistance training in trained men: a randomized controlled trial
Vargas S, Romance R, Petro JL, Bonilla DA, Galancho I, Espinar S, Kreider RB, Benitez-Porres J / Journal of the International Society of Sports Nutrition
Key point: ケトジェニックグループは通常食グループより体脂肪減少が有意に大きかった(-2.2kg vs -1.5kg)
- ReviewConfidence: Moderate2004
Vitamin and mineral status: effects on physical performance
Lukaski HC / Nutrition
Key point: 鉄・ビタミンD・マグネシウムなどの欠乏は有酸素パフォーマンスと筋力に明確な悪影響を与える
- Randomized controlled trialConfidence: Moderate2016
Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men
Schoenfeld BJ, Pope ZK, Benik FM, Hester GM, Sellers J, Nooner JL, Schnak JA, Bond KF, Carter JM, Aragon AA / Journal of Strength and Conditioning Research
Key point: 3分休憩グループは1分休憩グループと比較して筋肉量の増加が有意に大きかった(上腕二頭筋・大腿四頭筋)
- Meta-analysisConfidence: Moderate2018
Effects of Taurine Supplementation on Exercise Performance and Muscle Fatigue: A Meta-Analysis
Waldron M, et al. / Sports Medicine
Key point: Significant improvement in endurance (time to exhaustion) with moderate effect size
- Randomized controlled trialConfidence: Moderate2015
Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial
Wankhede S,Langade D,Joshi K,Sinha SR,Bhattacharyya S / Journal of the International Society of Sports Nutrition
Key point: Bench press and leg extension strength significantly improved vs placebo
- Randomized controlled trialConfidence: Moderate2010
Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness
Pérez-Guisado J,Jakeman PM / Journal of Strength and Conditioning Research
Key point: Citrulline malate increased bench press repetitions by an average of 52.92%
- Meta-analysisConfidence: Moderate2015
Effects of vitamin D supplementation on muscle strength in athletes: A systematic review
Tomlinson PB,Joseph C,Angioi M / Journal of Science and Medicine in Sport
Key point: Vitamin D supplementation may improve muscle strength in deficient athletes
- Meta-analysisConfidence: Moderate2018
Caffeine ingestion improves muscular strength and power (meta-analysis)
Grgic J, et al. / Journal of the International Society of Sports Nutrition
Key point: Small gains in maximal strength and power
- Meta-analysisConfidence: High2017
Creatine supplementation augments gains in strength and lean mass from resistance training (meta-analysis)
Chilibeck PD, et al. / Open Access Journal of Sports Medicine
Key point: Significantly greater lean-mass gains with creatine
- Meta-analysisConfidence: High2018
Protein supplementation augments resistance-training-induced gains in muscle mass and strength (meta-analysis)
Morton RW, et al. / British Journal of Sports Medicine
Key point: Protein adds to lean-mass and strength gains
- ObservationalConfidence: Low2011
Sleep extension improves athletic performance
Mah CD, et al. / Sleep
Key point: Sprint, shooting accuracy and reaction time improved
Supplements
Related supplements
Beetroot (Dietary Nitrate)
Confidence: ModerateDietary Nitrate, Beetroot Extract
Dietary nitrate found abundantly in beetroot is reported to be converted in the body via nitrite to nitric oxide (NO), promoting vasodilation and improved oxygen utilization efficiency. Multiple studies have shown modest benefits for aerobic and endurance performance, including improvements in VO2max and time-trial completion. Effects tend to be more pronounced in recreational to intermediate-level athletes than in elite competitors.
Betaine (Trimethylglycine)
Confidence: ModerateBetaine (Trimethylglycine, TMG)
Betaine is an amino acid derivative that acts as a methyl donor involved in creatine synthesis. Multiple RCTs have reported improvements in upper-body strength and muscle power, though results for lower-body outcomes are mixed. Cardiovascular benefits via homocysteine reduction are also under investigation.
L-Theanine
Confidence: ModerateL-Theanine (green tea-derived amino acid)
An amino acid found in green tea, research suggests it increases alpha-wave activity to promote calm focus without sedation. Combined with caffeine, it may attenuate jitteriness and anxiety while preserving alertness. Evidence for standalone strength or performance benefits is limited; it is most studied as part of a caffeine stack.
Electrolytes
Confidence: ModerateSodium, potassium, magnesium and other minerals
Minerals that act as ions in body fluids. A systematic review reports that dehydration of 2%+ body weight significantly impairs performance, and that for exercise over 60 minutes a sodium-containing electrolyte drink maintains performance better than water alone. Sodium loss during prolonged exercise is linked to muscle cramps and hyponatremia risk.
Ashwagandha
Confidence: ModerateWithania somnifera root extract
An adaptogen herb used in Ayurvedic medicine. Multiple RCTs have confirmed associations with reduced cortisol, improved sleep, and enhanced muscle strength — making it one of the better-researched natural supplements.
Citrulline
Confidence: ModerateL-Citrulline / Citrulline Malate
A non-essential amino acid that acts as a nitric oxide precursor, promoting vasodilation and improving blood flow and oxygen delivery to muscles. Has comparatively strong evidence as a pre-workout. Most research uses the citrulline malate complex.
Vitamin D
Confidence: ModerateVitamin D3 (cholecalciferol)
A fat-soluble vitamin synthesized in the skin from sunlight. Involved in bone metabolism, immune function, and muscle function. Deficiency is common in indoor lifestyles and low-sunlight environments. Athletes show high deficiency rates, and associations with muscle strength, immunity, and bone density are well-researched.
Caffeine
Confidence: ModerateAnhydrous caffeine
A pre-workout staple. Alongside alertness and focus, it gives a small boost to strength, power and endurance. Tolerance builds with habitual use, so timing matters.
Creatine
Confidence: HighCreatine monohydrate
One of the most studied supplements, with strong evidence for efficacy and safety. Supports high-intensity performance and gains in lean mass and strength during resistance training.
Articles
Related reads
- Research vs Bro-science
"Can't Build Muscle After 40" — Myth or Reality? Aging vs. the Research
"I'm too old to build muscle" — a common refrain from trainees in their 40s and 50s. Testosterone and growth hormone do decline with age. But is the muscle-building window actually closed? The research says otherwise.
Shingo Yoshizaki
- Research vs Bro-science
Is HMB Really a Superior Muscle-Building Supplement to Creatine? The HMB Hype vs. Research
HMB (beta-hydroxy-beta-methylbutyrate), a leucine metabolite, is marketed for stimulating muscle protein synthesis and preventing catabolism. But how well does the "guaranteed gains" claim hold up in research, especially for trained individuals?
Shingo Yoshizaki
- Research vs Bro-science
"I Got Stronger in 2 Weeks" — Is That Muscle or Something Else? Training Timeline vs. Research
Many new lifters feel noticeably stronger after 2–3 weeks. But what's actually changing? How long until real muscle hypertrophy — an increase in muscle cross-sectional area — actually occurs? The research timeline differs from gut feeling.
Shingo Yoshizaki
- Research vs Bro-science
Does No 'Feeling' Mean Creatine Isn't Working? Common Belief vs. Research
"I don't feel anything from it" and "it doesn't work for me" are among the most common reasons people stop taking creatine. But these conclusions likely stem from a misunderstanding of how creatine actually works. This article examines whether subjective feel is a valid metric for one of the most evidence-backed supplements in sports nutrition.
Shingo Yoshizaki
- Research vs Bro-science
Does Training More Often Mean More Gains? High Frequency vs. What the Research Shows
"Hit the same muscle group three or more times a week and your gains will accelerate" — it's advice repeated across social media and YouTube channels. The logic sounds intuitive, but does simply training more often actually produce more results? When you factor in total volume and recovery, the picture turns out to be more nuanced.
Shingo Yoshizaki
- Research vs Bro-science
Is caffeine only for cardio, useless for lifting? Lore vs research
'Caffeine is an endurance tool — it doesn't help your max lifts.' We test this common line against the research on maximal strength, dosing, and tolerance. This time the lore loses a round.
Hirotsugu Yoshimura