Condition

Swimming Performance

Swimming performance is how fast and how long a swimmer can go, drawing on stored phosphocreatine for sprints, anaerobic capacity for middle distances, and aerobic endurance for longer events. Caffeine has the strongest evidence and creatine comes next, but the swimming results available cover beta-alanine, where two small studies found anaerobic capacity improved. Those studies included just 41 people, so the evidence is limited, and creatine showed no clear aerobic difference.

Sources: PMID 39032921; PMID 19935102

Supplements studied: 5
Graded outcomes: 5
Trials: 23
People studied: 724

Evidence by supplement

Strong
Moderate
Limited
Very limited

5 supplements

Beta-Alanine

Beta-Alanine: outcomes studied for Swimming Performance
Grade	Outcome	Effect	Size	Studies	People
	Anaerobic Capacity Small Improvement	Improves (the measure goes up)	Small effect	2 studies	41 people
Studies that measured anaerobic capacity The effect of beta-alanine supplementation on power performance during repeated sprint activityJ Strength Cond Res · PMID 19935102 Effect of Beta-Alanine Supplementation on Maximal Intensity Exercise in Trained Young Male Individuals: A Systematic Review and Meta-Analysis.Int J Sport Nutr Exerc Metab · PMID 39032921
	Anaerobic Exercise Performance	Improves (the measure goes up)		3 studies	1,461 people
Studies that measured anaerobic exercise performance β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysisBr J Sports Med · PMID 27797728 Effects of Beta-Alanine Supplementation on Physical Performance in Aerobic-Anaerobic Transition Zones: A Systematic Review and Meta-Analysis.Nutrients · PMID 32824885 Effects of beta-alanine supplementation on Yo-Yo test performance: A meta-analysis.Clin Nutr ESPEN · PMID 34024507

Magnesium

Magnesium: outcomes studied for Swimming Performance
Grade	Outcome	Effect	Size	Studies	People
	Aerobic Exercise Metrics Moderate Improvement	Improves (the measure goes up)	Moderate effect		23 people
	Blood glucose	Improves (the measure goes down)		17 studies	23 people
Studies that measured blood glucose Efficacy of Magnesium Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Meta-analysis.J ASEAN Fed Endocr Soc · PMID 33442083 Oral magnesium supplementation in insulin-requiring Type 2 diabetic patientsDiabet Med · PMID 9632126 The effect of lowering blood pressure by magnesium supplementation in diabetic hypertensive adults with low serum magnesium levels: a randomized, double-blind, placebo-controlled clinical trialJ Hum Hypertens · PMID 19020533 and 14 more on the Magnesium page
	Muscle Oxygenation	Improves (the measure goes up)		1 study	23 people
Studies that measured muscle oxygenation On the significance of magnesium in extreme physical stressCardiovasc Drugs Ther · PMID 9794094
	Insulin	Changes; see studies			23 people

Sodium Bicarbonate

Aerobic Exercise Metrics: improves
Serum Bicarbonate: improves
Anaerobic Capacity: improves

Sodium Bicarbonate: outcomes studied for Swimming Performance
Grade	Outcome	Effect	Size	Studies	People
	Aerobic Exercise Metrics Small Improvement	Improves (the measure goes up)	Small effect		6 people
	Serum Bicarbonate	Improves (the measure goes up)		26 studies	25 people
Studies that measured serum bicarbonate Effects of various sodium bicarbonate loading protocols on the time-dependent extracellular buffering profileJ Strength Cond Res · PMID 20040895 Acid-base balance during repeated bouts of exercise: influence of HCO3Int J Sports Med · PMID 6094373 Effects of sodium bicarbonate ingestion on prolonged intermittent exerciseMed Sci Sports Exerc · PMID 12900682 and 23 more on the Sodium Bicarbonate page
	Anaerobic Capacity	Improves (the measure goes up)		11 studies	33 people
Studies that measured anaerobic capacity Sodium bicarbonate improves swimming performanceInt J Sports Med · PMID 18004687 Sodium bicarbonate ingestion and repeated swim sprint performanceJ Strength Cond Res · PMID 20881504 Sodium bicarbonate ingestion improves performance in interval swimmingEur J Appl Physiol Occup Physiol · PMID 2849539 and 8 more on the Sodium Bicarbonate page
	Power Output	Improves (the measure goes up)		6 studies	10 people
Studies that measured power output Reliability and effect of sodium bicarbonate: buffering and 2000-m rowing performanceInt J Sports Physiol Perform · PMID 22634964 Influence of sodium bicarbonate on performance and hydration in lightweight rowingInt J Sports Physiol Perform · PMID 21941012 The effect of induced alkalosis and acidosis on plasma lactate and work output in elite oarsmenEur J Appl Physiol Occup Physiol · PMID 2548862 and 3 more on the Sodium Bicarbonate page
	Blood Acidity	Changes; see studies		4 studies	25 people
Studies that measured blood acidity Acidosis stimulates beta-endorphin release during exerciseJ Appl Physiol · PMID 7836218 Time course of blood bicarbonate and pH three hours after sodium bicarbonate ingestionInt J Sports Physiol Perform · PMID 19208932 Effects of sodium bicarbonate on nitrogen metabolism and ketone bodies during very low energy protein diets in obese subjectsMetabolism · PMID 2556622 and 1 more on the Sodium Bicarbonate page
	Blood Lactate (Exercise)	Changes; see studies		2 studies	25 people

Creatine

Aerobic Exercise Metrics
Power Output: improves
Anaerobic Capacity: improves

Creatine: outcomes studied for Swimming Performance
Grade	Outcome	Effect	Size	Studies	People
	Aerobic Exercise Metrics No effect		NoneNo effect	2 studies	26 people
Studies that measured aerobic exercise metrics Creatine supplementation does not enhance submaximal aerobic training adaptations in healthy young men and womenEur J Appl Physiol · PMID 16896727 A randomized, controlled trial of creatine monohydrate in patients with mitochondrial cytopathiesMuscle Nerve · PMID 9390662
	Power Output	Improves (the measure goes up)		44 studies	112 people
Studies that measured power output Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flowMetabolism · PMID 11735088 Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performanceInt J Sport Nutr Exerc Metab · PMID 19033611 The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levelsJ Int Soc Sports Nutr · PMID 19228401 and 41 more on the Creatine page
	Anaerobic Capacity	Improves (the measure goes up)		11 studies	70 people
Studies that measured anaerobic capacity Short-term creatine supplementation does not improve muscle activation or sprint performance in humansEur J Appl Physiol · PMID 14574579 Creatine supplementation: effects on urinary excretion and anaerobic performanceJ Sports Med Phys Fitness · PMID 14625517 Creatine supplementation and performance in 6 consecutive 60 meter sprintsJ Physiol Biochem · PMID 15957245 and 8 more on the Creatine page
	Weight	Improves (the measure goes down)		10 studies	60 people
Studies that measured weight Creatine monohydrate supplementation on body weight and percent body fatJ Strength Cond Res · PMID 14636103 Reliability and detecting change following short-term creatine supplementation: comparison of two-component body composition methodsJ Strength Cond Res · PMID 17530953 Effects of creatine supplementation on aerobic power and cardiovascular structure and functionJ Sci Med Sport · PMID 16248471 and 7 more on the Creatine page
	Swimming Performance Metrics	Improves (the measure goes up)		7 studies	357 people
Studies that measured swimming performance metrics Creatine supplementation does not improve sprint performance in competitive swimmersMed Sci Sports Exerc · PMID 8933496 Effects of creatine supplementation on the performance and body composition of competitive swimmersJ Nutr Biochem · PMID 15302082 Swim performance following creatine supplementation in Division III athletesJ Strength Cond Res · PMID 12930165 and 4 more on the Creatine page
	Hydration (Total Body Water)	Improves (the measure goes up)		5 studies	18 people
	Muscle Mass	Improves (the measure goes up)		5 studies	62 people
	Creatinine	Improves (the measure goes up)		3 studies	34 people
	IGF-1	Improves (the measure goes up)		2 studies	26 people
	Growth Hormone	Improves (the measure goes up)		1 study	46 people
	Heart Rate	Improves (the measure goes down)		1 study	16 people
	Testosterone	Improves (the measure goes up)		1 study	20 people
	Blood Lactate (Exercise)	Changes; see studies			54 people
	Body Fat	Improves (the measure goes down)			46 people
	Cortisol	Improves (the measure goes down)			20 people
	Fatigue Symptoms	Improves (the measure goes down)			38 people
	Training Volume	Improves (the measure goes up)			58 people

L-Carnitine

Blood Acidity
Blood Lactate (Exercise): changes; see studies
Blood Carnitine: improves

L-Carnitine: outcomes studied for Swimming Performance
Grade	Outcome	Effect	Size	Studies	People
	Blood Acidity No effect		NoneNo effect		20 people
	Blood Lactate (Exercise)	Changes; see studies		5 studies	20 people
Studies that measured blood lactate (exercise) Clinical Effects of L-Carnitine Supplementation on Physical Performance in Healthy Subjects, the Key to Success in Rehabilitation: A Systematic Review and Meta-Analysis from the Rehabilitation Point of View.J Funct Morphol Kinesiol · PMID 34842765 The effects of acute L-carnitine supplementation on endurance performance of athletesJ Strength Cond Res · PMID 24263659 Effect of propionyl-L-carnitine on exercise performance in peripheral arterial diseaseMed Sci Sports Exerc · PMID 11528327 and 2 more on the L-Carnitine page
	Blood Carnitine	Improves (the measure goes up)		2 studies	20 people
Studies that measured blood carnitine The effects of L-carnitine supplementation on performance during interval swimmingInt J Sports Med · PMID 8063466 L-carnitine supplementation in patients with cystic acne on isotretinoin therapyJ Eur Acad Dermatol Venereol · PMID 10642057

Key findings

Anaerobic CapacityBeta-AlanineImproves (the measure goes up)
Aerobic Exercise MetricsMagnesiumImproves (the measure goes up)
Blood AcidityL-Carnitine

The Swimming Performance Enhancement protocol

2 primary supplements · 6 supporting supplements

Creatine Monohydrate3–5 g daily (loading optional)
Caffeine3–6 mg/kg body weight 30–60 minutes before competition

See the full protocol

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Studies cited

2 studies from PubMed

Effects of Postexercise Sauna Bathing on Recovery of Swim Performance.Int J Sports Physiol Perform · PMID 31869820
The effect of respiratory muscle training on swimming performance: a systematic review and meta-analysis.Front Physiol · PMID 40746984