Condition
Warm- or Hot-Weather Exercise Performance
Exercising in the heat forces your body to work harder to cool itself while also powering the workout, which can blunt performance and, in severe cases, lead to heat illness. The evidence is strongest for electrolytes and carbohydrates, which replace minerals lost in sweat and fuel long efforts. Small trials of quercetin, betaine and tyrosine, with 10 to 31 people, found no clear difference in performance measures.
Sources: PMID 21558570
- Supplements studied
- 5
- Graded outcomes
- 5
- Trials
- 14
- People studied
- 327
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Aldosterone Moderate Increase | Improves (the measure goes up) | Moderate effect | 20 people | |||
| Blood Pressure No effect | NoneNo effect | 44 people | ||||
| Power Output | Improves (the measure goes up) | 44 studies | 20 people | |||
Studies that measured power output
| ||||||
| Muscle Creatine Content | Improves (the measure goes up) | 11 studies | 21 people | |||
Studies that measured muscle creatine content
| ||||||
| Weight | Changes; see studies | 10 studies | 20 people | |||
Studies that measured weight | ||||||
| Hydration (Total Body Water) | Improves (the measure goes up) | 5 studies | 221 people | |||
| Creatinine | Improves (the measure goes up) | 3 studies | 20 people | |||
| Heart Rate | Changes; see studies | 1 study | 20 people | |||
| Sprint Performance Metrics | Improves (the measure goes up) | 1 study | 20 people | |||
| Fatigue Resistance | Changes; see studies | 21 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Anaerobic Capacity No effect | NoneNo effect | 1 study | 10 people | |||
Studies that measured anaerobic capacity | ||||||
| Exercise-induced Stress Response | Changes; see studies | 1 study | 8 people | |||
Studies that measured exercise-induced stress response | ||||||
| Rating of Perceived Exertion | Improves (the measure goes up) | 1 study | 10 people | |||
Studies that measured rating of perceived exertion | ||||||
| Hydration (Total Body Water) | Improves (the measure goes up) | 10 people | ||||
| Intestinal Permeability | Improves (the measure goes up) | 8 people | ||||
| Training Volume | Improves (the measure goes up) | 10 people | ||||
L-Tyrosine
- Aerobic Exercise Metrics
- Heart Rate: changes; see studies
- Rating of Perceived Exertion: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Aerobic Exercise Metrics No effect | NoneNo effect | 31 people | ||||
| Heart Rate | Changes; see studies | 5 studies | 31 people | |||
| Rating of Perceived Exertion | Improves (the measure goes up) | 3 studies | 23 people | |||
| Alertness | Improves (the measure goes up) | 1 study | 8 people | |||
| Blood glucose | Changes; see studies | 1 study | 8 people | |||
Studies that measured blood glucose | ||||||
| Body Temperature | Improves (the measure goes up) | 1 study | 16 people | |||
| Blood Lactate (Exercise) | Changes; see studies | 8 people | ||||
| Power Output | Improves (the measure goes up) | 15 people | ||||
| Vigor/Activity | Improves (the measure goes up) | 8 people | ||||
| Weight | Changes; see studies | 7 people | ||||
Betaine
- Anaerobic Capacity
- Oxygen Uptake: improves
- Blood glucose
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Anaerobic Capacity No effect | NoneNo effect | 10 people | ||||
| Oxygen Uptake | Improves (the measure goes up) | 1 study | 10 people | |||
Studies that measured oxygen uptake | ||||||
| Blood glucose | ||||||
| Heart Rate | Changes; see studies | 10 people | ||||
| Hematocrit | Improves (the measure goes up) | 10 people | ||||
| Hydration (Total Body Water) | Improves (the measure goes up) | 10 people | ||||
| Rating of Perceived Exertion | Improves (the measure goes up) | 10 people | ||||
Caffeine
- Adrenaline: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Adrenaline | Improves (the measure goes up) | 2 studies | 8 people | |||
Key findings
- AldosteroneImproves (the measure goes up)
- Anaerobic Capacity
- Blood Pressure
The Hot Weather Exercise Performance Support protocol
2 primary supplements · 7 supporting supplements
- Electrolytes (Sodium, Potassium, Magnesium)300–1,000 mg sodium per hour during prolonged hot weather exercise; potassium and magnesium as needed
- Glycerol1–1.5 g/kg body weight with fluid 60–120 min before exercise
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Studies cited
92 studies from PubMed
- Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization
- Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle
- Effects of L-tyrosine and carbohydrate ingestion on endurance exercise performance
- Effect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammation
- Thermotolerance and heat acclimation may share a common mechanism in humans
- No effect of nutritional adenosine receptor antagonists on exercise performance in the heat
- Chronic dietary tyrosine supplements do not affect mild essential hypertension
- Effects of Tyrosine on Parkinson's Disease: A Randomized, Double-Blind, Placebo-Controlled Trial
- Ingestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance
- Oral tyrosine supplementation improves exercise capacity in the heat
- Failure of oral tyrosine supplementation to improve exercise performance in the heat
- No Influence of Low-, Medium-, or High-Dose Tyrosine on Exercise in a Warm Environment
- Effect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment
- Oral L-Tyrosine Supplementation Improves Core Temperature Maintenance in Older Adults
- Oral l-tyrosine supplementation augments the vasoconstriction response to whole-body cooling in older adults
- L-tyrosine ameliorates some effects of lower body negative pressure stress
- Comparison of creatine monohydrate and carbohydrate supplementation on repeated jump height performance
- The effects of creatine supplementation on selected factors of tennis specific training
- Effect of Creatine Supplementation on Jumping Performance in Elite Volleyball Players
- Effect of oral creatine supplementation on urinary methylamine, formaldehyde, and formate
- Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans
- Effects of long-term creatine supplementation on liver and kidney functions in American college football players
- Creatine has no beneficial effect on skeletal muscle energy metabolism in patients with single mitochondrial DNA deletions: a placebo-controlled, double-blind 31P-MRS crossover study
- Resistance training with creatine monohydrate improves upper-body strength in patients with Parkinson disease: a randomized trial
- Brain serotonin and dopamine modulators, perceptual responses and endurance performance during exercise in the heat following creatine supplementation
- Does creatine supplementation hinder exercise heat tolerance or hydration status? A systematic review with meta-analyses
- Creatine use and exercise heat tolerance in dehydrated men
- Creatine and glycerol hyperhydration in trained subjects before exercise in the heat
- Creatine supplementation does not impair the thermoregulatory response during a bout of exercise in the heat
- Effects of acute creatine loading with or without carbohydrate on repeated bouts of maximal swimming in high-performance swimmers
- Creatine supplementation improves the anaerobic performance of elite junior fin swimmers
- Low dose creatine supplementation enhances sprint phase of 400 meters swimming performance
- Effect of creatine on swimming velocity, body composition and hydrodynamic variables
- Effect of oral creatine supplementation on single-effort sprint performance in elite swimmers
- Randomized controlled trial of dietary creatine as an adjunct therapy to physical training in chronic obstructive pulmonary disease
- Creatine supplementation during pulmonary rehabilitation in chronic obstructive pulmonary disease
- Effects of creatine supplementation on oxidative stress and inflammatory markers after repeated-sprint exercise in humans
- The effect of short-term creatine loading on active range of movement
- The effect of creatine supplementation on muscle fatigue and physiological indices following intermittent swimming bouts
- Effect of low-dose, short-duration creatine supplementation on anaerobic exercise performance
- Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women
- Effects of creatine loading on electromyographic fatigue threshold in cycle ergometry in college-age men
- Effect of creatine phosphate supplementation on anaerobic working capacity and body weight after two and six days of loading in men and women
- Effect of two and five days of creatine loading on anaerobic working capacity in women
- Effects of creatine supplementation on aerobic power and cardiovascular structure and function
- Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans
- Creatine supplementation reduces muscle inosine monophosphate during endurance exercise in humans
- Parallel increases in phosphocreatine and total creatine in human vastus lateralis muscle during creatine supplementation
- Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers
- Muscle glycogen supercompensation is enhanced by prior creatine supplementation
- Skeletal muscle total creatine content and creatine transporter gene expression in vegetarians prior to and following creatine supplementation
- Physiological responses to short-term exercise in the heat after creatine loading
- Mg2+-creatine chelate and a low-dose creatine supplementation regimen improve exercise performance
- Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function
- Effect of caffeine ingestion after creatine supplementation on intermittent high-intensity sprint performance
- The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial
- Effects of high dose oral creatine supplementation on anaerobic capacity of elite wrestlers
- Effects of two and five days of creatine loading on muscular strength and anaerobic power in trained athletes
- Effects of oral creatine and resistance training on serum myostatin and GASP-1
- Effects of creatine monohydrate supplementation on body composition and strength indices in experienced resistance trained women
- Creatine as a metabolic controller of skeletal muscles structure and function in strength exercises in humans
- The effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreaching
- Effects of creatine monohydrate and polyethylene glycosylated creatine supplementation on muscular strength, endurance, and power output
- Effect of different frequencies of creatine supplementation on muscle size and strength in young adults
- The effects of pre versus post workout supplementation of creatine monohydrate on body composition and strength
- The effects of supplementation with creatine and protein on muscle strength following a traditional resistance training program in middle-aged and older men
- Effect of thirty days of creatine supplementation with phosphate salts on anaerobic working capacity and body weight in men
- The effects of polyethylene glycosylated creatine supplementation on muscular strength and power
- Effect of short-term creatine supplementation on neuromuscular function
- Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes
- Effects of four weeks of high-intensity interval training and creatine supplementation on critical power and anaerobic working capacity in college-aged men
- Does nutritional supplementation influence adaptability of muscle to resistance training in men aged 48 to 72 years
- Effect of creatine ingestion after exercise on muscle thickness in males and females
- Creatine monohydrate increases strength in patients with neuromuscular disease
- Creatine supplementation and physical training in patients with COPD: a double blind, placebo-controlled study
- The Paradoxical Effect of Creatine Monohydrate on Muscle Damage Markers: A Systematic Review and Meta-Analysis
- Reliability and detecting change following short-term creatine supplementation: comparison of two-component body composition methods
- Creatine monohydrate supplementation on body weight and percent body fat
- Effects of creatine on body composition and strength gains after 4 weeks of resistance training in previously nonresistance-trained humans
- The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations
- Creatine supplementation improves muscular performance in older women
- Effects of creatine supplementation in taekwondo practitioners
- Effect of creatine and weight training on muscle creatine and performance in vegetarians
- Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study
- Effect of in-season creatine supplementation on body composition and performance in rugby union football players
- The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels
- Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performance
- Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow
- Effect of creatine monohydrate in improving cellular energetics and muscle strength in ambulatory Duchenne muscular dystrophy patients: a randomized, placebo-controlled 31P MRS study
- Caffeine can decrease insulin sensitivity in humans
- Effects of caffeine on the metabolic and catecholamine responses to exercise in 5 and 28 degrees C
- Influence of betaine consumption on strenuous running and sprinting in a hot environment