Citrulline for Bench Press? Caffeine Wins!

observational-study PMID: 35565718

Quick Summary: A recent study looked at how a pre-workout supplement with citrulline and other ingredients affected bench press performance compared to caffeine alone. The results showed that caffeine boosted bench press reps more effectively than the supplement.

Does Citrulline Help with Bench Press?

Researchers wanted to see if a pre-workout supplement, including citrulline, could improve bench press performance. They compared it to just caffeine. The study found that caffeine alone helped the participants do more bench press repetitions. The supplement with citrulline didn't offer any extra benefit.

Study Details

Who was studied: 15 men who regularly lifted weights. They had an average of about 6 years of training experience.

How long: The study involved two separate workout sessions, about a week apart.

What they took:

Group 1: A pre-workout supplement with citrulline (8g), beta-alanine, arginine, taurine, tyrosine, and caffeine (300mg).
Group 2: Just caffeine (300mg).

What This Means For You

If you're looking to boost your bench press, this study suggests that caffeine might be a better choice than a pre-workout supplement containing citrulline and other ingredients. Caffeine is a well-known performance enhancer, and this research supports that. You might save money by sticking with caffeine if your goal is to increase bench press reps.

Study Limitations

Small Group: The study only included 15 men, so the results might not apply to everyone.

Short-Term: The study only looked at the immediate effects of the supplements, not long-term use.

Other Ingredients: The pre-workout supplement had other ingredients besides citrulline, so it's hard to know if citrulline alone would have the same effect.

Only Men: The study was only done on men, so the results might be different for women.

Key Findings

The study found that caffeine alone (300 mg) significantly improved bench press repetition volume (7.6 ± 2.3 reps) compared to a multi-ingredient pre-workout supplement (MIPS) containing L-citrulline malate (8g), beta-alanine, arginine alpha-ketoglutarate, L-taurine, L-tyrosine, and caffeine (6.9 ± 2.2 reps; p=0.018). No differences were observed in psychological measures (feeling scale, felt arousal scale, session rating of perceived exertion) between conditions. Researchers concluded that MIPS offered no additional benefits over caffeine alone and may be less cost-effective.

Study Design

This was a single-blind cross-over observational study conducted in 2022. Fifteen resistance-trained males (n=15; age: 25.1 ± 4.3 years; weight: 83.92 ± 8.95 kg; training experience: 5.6 ± 3.38 years) participated in two testing sessions separated by 7 days. Participants were blinded to supplementation order (MIPS vs. caffeine), but researchers were not. The cross-over design allowed within-subject comparisons.

Dosage & Administration

MIPS: Included 8g L-citrulline malate, 3.2g beta-alanine, 2g arginine alpha-ketoglutarate, 1g L-taurine, 500mg L-tyrosine, and 300mg anhydrous caffeine.
Caffeine-only: 300mg anhydrous caffeine (matched to MIPS caffeine content).
Both supplements were administered in capsule form with 240ml water, 30 minutes pre-training.

Results & Efficacy

Bench press volume: Caffeine alone increased total repetitions vs. MIPS (7.6 ± 2.3 vs. 6.9 ± 2.2; p=0.018).
Psychological measures: No significant differences in FS (p=0.14), FAS (p=0.42), or sRPE (p=0.21) between conditions.
Statistical significance: Defined as p < 0.05; confidence intervals not reported in the summary.

Limitations

Small sample size (n=15) limits generalizability and statistical power.
Single-blind design: Participants were aware they were receiving supplements, potentially biasing outcomes.
Short-term effects: Only acute supplementation effects were tested; long-term impacts remain unknown.
Mixed supplement composition: Other ingredients in MIPS (e.g., beta-alanine, arginine) may have interacted with caffeine, obscuring L-citrulline’s individual role.
Homogeneous cohort: Findings apply only to trained males; effects in females, untrained individuals, or varied populations are untested.

Clinical Relevance

For resistance-trained males, caffeine alone (300mg) may be more effective than a MIPS containing L-citrulline malate for enhancing short-term bench press strength endurance. The addition of other ingredients like L-citrulline did not improve performance or psychological responses, suggesting potential redundancy in multi-ingredient formulations. Users seeking cost-effective ergogenic aids might prioritize caffeine over complex pre-workout blends, though individual variability and training goals should be considered. Further research is needed to isolate L-citrulline’s effects at varying doses in different populations.