Condition
Rugby Performance
Rugby is a contact sport that demands strength, power, speed, endurance and recovery from repeated impacts. Creatine and caffeine carry the strongest evidence for sports like this, and small trials found creatine improved alertness while sodium bicarbonate improved anaerobic capacity. Those specific findings are limited, though, since the studies were small and some bicarbonate work involved swimmers rather than rugby players.
Sources: PMID 17185404; PMID 21324203; PMID 18004687
- Supplements studied
- 5
- Graded outcomes
- 5
- Trials
- 6
- People studied
- 113
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Anaerobic Capacity Small Improvement | Improves (the measure goes up) | Small effect | 10 studies | |||
| Serum Bicarbonate | Improves (the measure goes up) | 26 studies | 25 people | |||
| Power Output | Improves (the measure goes up) | 6 studies | 25 people | |||
| Blood Acidity | Changes; see studies | 4 studies | 25 people | |||
Studies that measured blood acidity | ||||||
| Blood Lactate (Exercise) | Changes; see studies | 2 studies | 25 people | |||
Studies that measured blood lactate (exercise) | ||||||
Caffeine
- Cortisol: worsens
- Power Output: improves
- Training Volume: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Cortisol Increase | Worsens (the measure goes up) | 1 study | 16 people | |||
| Power Output | Improves (the measure goes up) | 3 studies | 16 people | |||
Studies that measured power output | ||||||
| Training Volume | Improves (the measure goes up) | 1 study | 16 people | |||
Studies that measured training volume | ||||||
| Testosterone | Improves (the measure goes up) | 16 people | ||||
Spirulina
- Power Output
- Sprint Performance Metrics: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Power Output No effect | 1 study | 22 people | ||||
| Sprint Performance Metrics | Improves (the measure goes up) | 22 people | ||||
Tribulus Terrestris
- Body Fat
- Testosterone
- Muscle Mass
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Body Fat No effect | NoneNo effect | 2 studies | 22 people | |||
| Testosterone No effect | 3 studies | |||||
Studies that measured testosterone
| ||||||
| Muscle Mass No effect | 1 study | |||||
Studies that measured muscle mass | ||||||
| Power Output | ||||||
Key findings
- Anaerobic CapacityImproves (the measure goes up)
- AlertnessImproves (the measure goes up)
- CortisolWorsens (the measure goes up)
The Rugby Performance Enhancement protocol
2 primary supplements · 5 supporting supplements
- Creatine Monohydrate3–5 g daily (or 20 g/day x 5 days loading, then 3–5 g maintenance)
- Caffeine3–6 mg/kg body weight, 30–60 min before match/training
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Studies cited
100 studies from PubMed
- Does creatine supplementation improve glycemic control and insulin resistance in healthy and diabetic patients? A systematic review and meta-analysis.
- Effects of spirulina and wakame consumption on intestinal cholesterol absorption and serum lipid concentrations in non-hypercholesterolemic adult men and women
- The antioxidant, immunomodulatory, and anti-inflammatory activities of Spirulina: an overview.
- Effect of Spirulina maxima on postprandial lipemia in young runners: a preliminary report
- Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress
- Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players
- Does creatine supplementation improve the plasma lipid profile in healthy male subjects undergoing aerobic training
- Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training
- Wheat grass supplementation decreases oxidative stress in healthy subjects: a comparative study with spirulina
- Creatine supplementation increases glycogen storage but not GLUT-4 expression in human skeletal muscle
- Creatine supplementation affects glucose homeostasis but not insulin secretion in humans
- Creatine supplementation and health variables: a retrospective study
- 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 1,3-dimethylamylamine and caffeine alone or in combination on heart rate and blood pressure in healthy men and women
- Ergogenic effect of varied doses of coffee-caffeine on maximal aerobic power of young African subjects
- The effect of caffeine ingestion on mood state and bench press performance to failure
- Effect of Caffeine on LT, VT and HRVT
- Metabolic effects of caffeine ingestion and physical work in 75-year old citizens. A randomized, double-blind, placebo-controlled, cross-over study
- Dose response effects of a caffeine-containing energy drink on muscle performance: a repeated measures design
- Acute caffeine ingestion increases voluntarily chosen resistance training load following limited sleep
- Effects of caffeine on the metabolic and catecholamine responses to exercise in 5 and 28 degrees C
- Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men
- Effect of two doses of caffeine on muscular function during isokinetic exercise
- Dose effect of caffeine on testosterone and cortisol responses to resistance exercise
- The effects of low-dose caffeine on perceived pain during a grip to exhaustion task
- Caffeine increases sweating sensitivity via changes in sudomotor activity during physical loading
- Effects of caffeinated and decaffeinated coffee on biological risk factors for type 2 diabetes: a randomized controlled trial
- Caffeine and sprinting performance: dose responses and efficacy
- Effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes
- Caffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists
- The effects of different doses of caffeine on endurance cycling time trial performance
- Effect of caffeine ingestion on time trial performance in cyclists: a systematic review and meta-analysis.
- Effect of ambient temperature on caffeine ergogenicity during endurance exercise
- The influence of a CYP1A2 polymorphism on the ergogenic effects of caffeine
- Caffeine ingestion, affect and perceived exertion during prolonged cycling
- Effect of caffeine intake on pain perception during high-intensity exercise
- Caffeine as an analgesic adjuvant for acute pain in adults
- Caffeine for the prevention of injuries and errors in shift workers.
- Caffeine enhances working memory for extraverts
- Comparing the benefits of caffeine, naps and placebo on verbal, motor and perceptual memory
- Subjective, behavioral, and physiological effects of acute caffeine in light, nondependent caffeine users
- Effects of caffeine and glucose, alone and combined, on cognitive performance
- Effects of acute caffeine consumption following sleep loss on cognitive, physical, occupational and driving performance: A systematic review and meta-analysis.
- Effect of caffeine on reactive agility time when fresh and fatigued
- Effects of Nutritional Interventions on Accuracy and Reaction Time with Relevance to Mental Fatigue in Sporting, Military, and Aerospace Populations: A Systematic Review and Meta-Analysis.
- Effect of caffeine on target detection and rifle marksmanship
- Association of the anxiogenic and alerting effects of caffeine with ADORA2A and ADORA1 polymorphisms and habitual level of caffeine consumption
- Caffeine: a double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers
- Caffeine can decrease insulin sensitivity in humans
- Effects of caffeine on glucose tolerance: a placebo-controlled study
- Caffeine ingestion decreases glucose disposal during a hyperinsulinemic-euglycemic clamp in sedentary humans
- Caffeinated coffee does not acutely affect energy intake, appetite, or inflammation but prevents serum cortisol concentrations from falling in healthy men
- Influence of caffeine on perception of effort, metabolism and exercise performance following a high-fat meal
- Impact of acute caffeine ingestion on endothelial function in subjects with and without coronary artery disease
- Caffeine and opening the eyes have additive effects on resting arousal measures
- Effects of diurnal variation and caffeine consumption on Test of Variables of Attention (TOVA) performance in healthy young adults
- Caffeine supplementation and multiple sprint running performance
- Effects of caffeine on repeated sprint ability, reactive agility time, sleep and next day performance
- Genetic determinants of blood pressure responses to caffeine drinking
- Caffeine and Physiological Responses to Submaximal Exercise: A Meta-Analysis
- Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses
- Effects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis.
- Caffeine for asthma.
- The Effect of Consuming Caffeine Before Late Afternoon/Evening Training or Competition on Sleep: A Systematic Review with Meta-Analysis.
- The effect of caffeine on subsequent sleep: A systematic review and meta-analysis.
- The Prophylactic Effect of Acetaminophen and Caffeine on Post Dural Puncture Headache after Spinal Anesthesia for Cesarean Section: A Randomized Double-Blind Clinical Trial.
- The Effect of Pre-Exercise Caffeine and Glucose Ingestion on Endurance Capacity in Hypoxia: A Double-Blind Crossover Trial.
- Effect of creatine monohydrate in improving cellular energetics and muscle strength in ambulatory Duchenne muscular dystrophy patients: a randomized, placebo-controlled 31P MRS study
- Creatine for treating muscle disorders.
- Creatine monohydrate enhances strength and body composition in Duchenne muscular dystrophy
- Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow
- Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performance
- The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels
- Effect of in-season creatine supplementation on body composition and performance in rugby union football players
- Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study
- Effect of creatine and weight training on muscle creatine and performance in vegetarians
- Effects of creatine supplementation in taekwondo practitioners
- Creatine supplementation improves muscular performance in older women
- The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations
- Effects of creatine on body composition and strength gains after 4 weeks of resistance training in previously nonresistance-trained humans
- Creatine monohydrate supplementation on body weight and percent body fat
- Reliability and detecting change following short-term creatine supplementation: comparison of two-component body composition methods
- Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain
- Efficacy of Creatine Supplementation Combined with Resistance Training on Muscle Strength and Muscle Mass in Older Females: A Systematic Review and Meta-Analysis.
- The Paradoxical Effect of Creatine Monohydrate on Muscle Damage Markers: A Systematic Review and Meta-Analysis
- Creatine supplementation and physical training in patients with COPD: a double blind, placebo-controlled study
- Creatine monohydrate increases strength in patients with neuromuscular disease
- Effect of creatine ingestion after exercise on muscle thickness in males and females
- Does nutritional supplementation influence adaptability of muscle to resistance training in men aged 48 to 72 years
- Effects of four weeks of high-intensity interval training and creatine supplementation on critical power and anaerobic working capacity in college-aged men
- Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes
- Effect of short-term creatine supplementation on neuromuscular function
- The effects of polyethylene glycosylated creatine supplementation on muscular strength and power
- Effect of thirty days of creatine supplementation with phosphate salts on anaerobic working capacity and body weight in men
- The effects of supplementation with creatine and protein on muscle strength following a traditional resistance training program in middle-aged and older men
- The effects of pre versus post workout supplementation of creatine monohydrate on body composition and strength
- Effect of different frequencies of creatine supplementation on muscle size and strength in young adults
- Effects of creatine monohydrate and polyethylene glycosylated creatine supplementation on muscular strength, endurance, and power output
- The effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreaching