Sports Supplements & Ergogenic Aids

Ergogenic Aid Definition

Any substance, dietary manipulation, training technique, or mechanical apparatus designed to enhance performance, increase lean mass, accelerate recovery, or improve training adaptations.

5 Classes of Ergogenic Aids

Nutritional, Physiological, Psychological, Biomechanical, and Pharmacological.

DSHEA (1994) & FDA Regulation

Supplements are not regulated like drugs; no pre-market safety or efficacy trials are required. The FDA must prove a product is unsafe after marketing to remove it.

Structure/Function vs. Health Claims

Structure/function describes effect on normal function (requires disclaimer); health claim describes reduced disease risk (requires FDA authorization).

Third-Party Testing Certifications

NSF Certified for Sport and Informed Choice; test for banned substances, verify label accuracy, and confirm absence of contaminants/heavy metals.

AIS ABCD Framework

Group A (strong evidence), Group B (emerging research), Group C (no proven benefit), Group D (banned/high contamination risk).

5 Steps to Evaluate a Supplement

1. Assess need, 2. Evaluate evidence, 3. Examine label & dose, 4. Check third-party certification, 5. Identify red flags.

Creatine Synthesis & Storage

Synthesized in liver, kidneys, and pancreas from glycine, arginine, and methionine; stored primarily in skeletal muscle as phosphocreatine (PCr).

Creatine Mechanism of Action

PCr donates high-energy phosphate to ADP via creatine kinase to rapidly regenerate ATP during short, high-intensity anaerobic efforts.

Creatine Dosing Protocols

Fast loading: 20 g/day for 5-7 days, then 3-5 g/day maintenance. Slow loading: 3-5 g/day continuously reaches saturation in ~28 days.

Creatine Genetic & Sex Differences

Response varies by baseline stores. Women have lower dietary intake and ~70-80% lower endogenous stores, showing strong strength and bone responses.

Caffeine Mechanism of Action

Competitive antagonist of adenosine receptors, blocking drowsiness, increasing CNS alertness, stimulating catecholamines, and lowering RPE.

Caffeine Dosing & Timing

3-6 mg/kg body weight consumed ~60 minutes prior to exercise. Doses >=9 mg/kg increase side effects without additional performance benefits.

Caffeine Genetics (CYP1A2 & ADORA2A)

CYP1A2 controls liver clearance (fast vs slow metabolizers); ADORA2A modulates anxiety susceptibility.

Beta-Alanine Mechanism of Action

Rate-limiting precursor in muscle carnosine synthesis; carnosine acts as an intracellular buffer binding free H+ to attenuate exercise-induced acidosis.

Beta-Alanine Performance Applications

High-intensity efforts lasting 4 to 10 minutes (middle-distance running, rowing, swimming, combat sports).

Beta-Alanine Dosing & Side Effects

4.5 to 6.4 g/day for >=4 weeks. Side effect: Paresthesia (skin tingling), prevented by sustained-release or split doses

Sodium Bicarbonate Mechanism of Action

Extracellular buffer that elevates blood HCO3- and pH, creating a steeper gradient to accelerate H+ and lactate efflux.

Sodium Bicarbonate Dosing & Side Effects

0.2 to 0.3 g/kg body weight 60-120 min pre-exercise. Side effects include severe GI distress (osmotic diarrhea, nausea, bloating).

Dietary Nitrate Mechanism (Enterosalivary Pathway)

Ingested nitrate is reduced to nitrite by oral bacteria, then to nitric oxide (NO), which vasodilates vessels and lowers oxygen cost of ATP.

Dietary Nitrate Dosing & 2025 Review

400-800 mg (6-13 mmol) 2-3 hours pre-exercise; improves time-to-exhaustion and muscular endurance.

L-Citrulline / Citrulline Malate Evidence

Bypasses liver to form L-arginine, driving nitric oxide production. 8 g pre-workout increased bench press reps by 52.9% and reduced DOMS.

L-Glutamine Applications & Evidence

Fuel for enterocytes and immune cells; aids intestinal barrier integrity in extreme conditions, but shows no direct benefit for muscle hypertrophy or strength.

Tart Cherry (Montmorency) Benefits

Rich in anthocyanins/polyphenols; acts as COX inhibitor, reducing inflammation, muscle damage, and DOMS, and improves sleep via phytomelatonin.

Collagen Peptides Protocol for Connective Tissue

10-15 g hydrolyzed collagen with ~50 mg Vitamin C 45-60 minutes before targeted loading enhances tendon/ligament collagen synthesis.