Sports Supplement Science: The Effects of Caffeine, Beta-Alanine, and Creatine on Cycling Performance

The sports supplement market is vast and full of questionable products, but among the hundreds of products claiming to enhance performance, only a few have been rigorously validated by science. This article focuses on three supplements with the strongest evidence base: caffeine, beta-alanine, and creatine, analyzing their effects on cycling performance one by one.

Caffeine: The “Legal Stimulant” of the Sports World

Mechanism of Action

Caffeine enhances sports performance primarily through the following mechanisms:

1. Adenosine receptor antagonism: Blocks adenosine from binding to receptors, reducing the perception of fatigue
2. Central nervous system stimulation: Enhances alertness, focus, and reaction speed
3. Increased fat oxidation: Promotes fat utilization as fuel during low-to-moderate intensity exercise
4. Reduced perceived exertion: The same exercise intensity feels easier (lower RPE)

Scientific Evidence

Meta-analysis results (2019, British Journal of Sports Medicine):

• Endurance performance improvement: 2-4%
• High-intensity performance improvement: 3-7%
• Most significant effects observed in time trial formats

For cyclists, a 2-4% performance improvement means a 40-minute time trial could be 1-2 minutes faster.

Optimal Usage Protocol

Dosage:

• Minimum effective dose: 2 mg per kg body weight
• Optimal dose: 3-6 mg per kg body weight
• Exceeding 6 mg/kg provides no additional benefit and increases side effects

Timing:

• Consume 30-60 minutes before exercise (peak plasma concentration takes approximately 45-60 minutes)
• For long-distance events, a small “top-up” dose (1-2 mg/kg) can be taken in the latter half

Source Comparison:

Source	Caffeine Content	Pros and Cons
Caffeine tablets	Precisely controllable	Most precise; recommended for racing
Black coffee (240ml)	~95mg	Contains other beneficial compounds, but dosage is imprecise
Caffeinated energy gels	25-50mg	Convenient for use while riding
Energy drinks	80-300mg	High sugar content; not recommended

Example protocol for a 70 kg rider:

• 45 minutes before race: 200mg caffeine tablet (~3 mg/kg)
• Mid-race (if needed): 1 caffeinated energy gel (+50mg)
• Total: 250mg (~3.6 mg/kg), within the optimal range

Precautions

• Tolerance: Regular coffee drinkers may experience diminished effects. Moderately reducing intake 1-2 days before competition can restore sensitivity
• Genetics: The CYP1A2 gene determines caffeine metabolism rate. “Slow metabolizers” may need lower doses or earlier intake
• Sleep impact: Using caffeine for afternoon or evening races/training may affect sleep that night
• Gastrointestinal issues: High doses may cause stomach discomfort; always test during training

Beta-Alanine: Combating Muscle Acidification

Mechanism of Action

Beta-alanine does not act directly; rather, it serves as a precursor for synthesizing carnosine. Carnosine plays a crucial “pH buffering” role in muscle:

1. Beta-alanine enters muscle cells
2. Binds with histidine to form carnosine
3. Carnosine neutralizes hydrogen ions (H+) produced during high-intensity exercise
4. Delays the decline in muscle pH (delays “acidification”)
5. Result: extended tolerance time for high-intensity exercise

Scientific Evidence

Meta-analysis results (2012, Amino Acids):

• Most effective for high-intensity efforts lasting 1-4 minutes
• Average performance improvement: 2.85%
• Diminishing effects for efforts exceeding 4 minutes
• No significant effect for efforts under 1 minute

Relevance for Cyclists

Beta-alanine is best suited for the following scenarios:

• Track pursuit events (4-minute all-out efforts)
• Short climbing surges in road races (2-5 minute climbs)
• Repeated attacks in criteriums
• Final sprint in time trials

For steady-paced long-distance riding, the effects are less pronounced.

Optimal Usage Protocol

Loading phase:

• 3.2-6.4 grams daily, divided into 3-4 doses
• Continue for 4-10 weeks to achieve carnosine saturation

Maintenance phase:

• 1.2-1.6 grams daily

Important notes:

• Beta-alanine is not a pre-race acute supplement; it requires several weeks of consistent use to be effective
• Common side effect: skin tingling (Paresthesia), harmless but potentially uncomfortable
• Dividing into smaller doses can reduce tingling
• Taking with meals improves absorption

Creatine: Not Just for the Gym

Mechanism of Action

Creatine plays a key role in the cellular energy system:

1. Stored in muscle as phosphocreatine (PCr)
2. Provides rapid energy during the first 5-15 seconds of high-intensity exercise
3. Accelerates ATP resynthesis
4. May promote post-training muscle repair and protein synthesis

Scientific Evidence

Effects on explosive power:

• Repeated sprint ability improvement: 5-15%
• Peak power output improvement: 3-8%

Effects on endurance performance:

• Traditional view holds that creatine is ineffective for endurance sports
• However, recent research suggests that in training incorporating high-intensity intervals, creatine may indirectly enhance endurance performance through improved training quality
• Creatine aids recovery after high-intensity training

Applicable Scenarios for Cyclists

Best suited for:

• Track racers (sprint, pursuit)
• Road racers requiring frequent explosive efforts
• Winter strength training periods
• Interval training phases (improving training quality)

Potentially unsuitable for:

• Pure climbers (weight gain may be a negative factor)
• Long-distance time trials (steady low-intensity efforts)

Optimal Usage Protocol

Rapid loading protocol (effective in 5-7 days):

• 20 grams daily, divided into 4 doses, for 5-7 days
• Followed by 3-5 grams daily for maintenance

Slow loading protocol (effective in 3-4 weeks):

• 3-5 grams daily for 3-4 weeks to reach saturation
• Same results, but requires more time

Recommended form:

• Creatine Monohydrate is the most researched and cost-effective form
• Other forms (creatine hydrochloride, buffered creatine, etc.) show no significant advantage

Common Concerns

“Does creatine damage the kidneys?”
Long-term use of research-safe doses of creatine (3-5g/day) in healthy individuals has shown no kidney damage. However, those with kidney disease should consult a physician.

“Will it cause weight gain?”
Creatine does cause weight gain, primarily from increased intramuscular water retention, approximately 1-2 kg. Climbers need to weigh the pros and cons.

Comparative Summary of the Three Supplements

Characteristic	Caffeine	Beta-Alanine	Creatine
Onset of effect	Immediate (30-60 minutes)	Slow (4-10 weeks)	Moderate (5 days-4 weeks)
Optimal exercise duration	All ranges	1-4 minutes	<30 seconds (direct) / All ranges (indirect)
Daily dosage	3-6 mg/kg (training days)	3.2-6.4g (loading) / 1.2g (maintenance)	3-5g
Side effects	Insomnia, anxiety, gastrointestinal	Skin tingling	Weight gain
Scientific support	Extremely strong	Strong	Extremely strong
Road race recommendation	Extremely high	Moderate	Moderate
King of the Mountains recommendation	Extremely high	Moderate-high	Low (weight considerations)
Time trial recommendation	Extremely high	Moderate	Moderate

Basic Principles of Supplement Use

1. Get your diet right first: Supplements are the icing on the cake; they cannot replace a balanced diet
2. Choose third-party certified products: Such as Informed Sport, NSF Certified for Sport
3. Test during training first: Never use a supplement for the first time on race day
4. Keep records: Dosage, timing, subjective feelings—find your personal optimal protocol
5. Consult professionals: Sports nutritionists or sports medicine physicians

Summary

Among the three supplements, caffeine is the most comprehensive and powerful choice for cyclists, suitable for nearly all race types. Beta-alanine is best suited for riders who frequently need short-duration, high-intensity output. Creatine is most valuable during strength training and interval training phases. Understanding the mechanisms of action and optimal usage protocols for each supplement is the key to truly benefiting from them, rather than simply wasting money.

Related Reading

• Sports Supplement Science: Research Support and Usage Recommendations for Caffeine, Beta-Alanine, and Creatine
• Caffeine and Cycling Performance: The Strongest Legal Supplement Supported by Sports Science
• Caffeine Supplementation Strategies for Cycling: Benefits, Timing, and Side Effect Management
• The Application of Caffeine in Cycling: Intake Timing and Dosage