Acute phenylcapsaicin supplementation improves CrossFit® performance: a randomized, triple-blind, placebo-controlled crossover trial.

Phenylcapsaicin improved squat performance at 70% 1RM in both load and repetitions compared to placebo.

• The deep squat was performed at 70% 1RM post-session.
• Statistical significance was reached at P ≤ 0.035 for both load and repetitions.
• The squat assessment occurred after the full CrossFit session including warm-up, weightlifting block, and WOD.
• This was a crossover design with 50 CF-trained athletes (50% women).

Phenylcapsaicin attenuated the decline in countermovement jump (CMJ) performance compared to placebo.

• CMJ was evaluated pre- and post-session in both conditions.
• The difference between groups was statistically significant (P < 0.001).
• Sex-stratified analysis showed that PC reduced CMJ loss specifically in men (P = 0.043).
• No specific CMJ magnitude values are reported in the abstract.

Phenylcapsaicin maintained weightlifting performance over time, with significantly higher load in round 9 compared to placebo.

• The interaction effect for weightlifting performance over time was significant (P interaction = 0.011).
• Significantly higher load was observed in round 9 specifically (P = 0.030).
• The weightlifting block was a standardized component of the CF session.
• No differences were observed during the WOD phase (P interaction ≥ 0.826).

Phenylcapsaicin significantly reduced delayed-onset muscle soreness (DOMS) at both 24 and 48 hours post-session.

• DOMS was assessed at 24-hour and 48-hour post-session time points.
• The difference between PC and placebo groups was statistically significant (P = 0.030).
• Lower DOMS was observed in the PC group at both time points.
• No specific DOMS magnitude values are reported in the abstract.

No significant differences between phenylcapsaicin and placebo were found for capillary lactate, rating of perceived exertion (RPE), perceived recovery status (PRS), or heart rate.

• All four physiological and perceptual measures showed no group differences (P interaction ≥ 0.340 for all).
• These variables were monitored throughout the CF session.
• Heart rate, capillary lactate, RPE, and PRS were all measured during the session.
• This indicates PC's performance benefits did not manifest through changes in these commonly measured parameters.

Sex-stratified analysis revealed that phenylcapsaicin effects differed between men and women for specific outcomes.

• PC reduced CMJ loss in men (P = 0.043).
• PC increased squat load in women (P = 0.021).
• The study included 50 CF-trained athletes with 50% women (25 men, 25 women).
• These sex-specific findings suggest potentially different mechanistic pathways or sensitivities to PC between sexes.

The study used a randomized, triple-blind, placebo-controlled crossover design with 2.5 mg phenylcapsaicin ingested 45 minutes before a standardized CrossFit session.

• Fifty CrossFit-trained athletes participated (50% women).
• The dose was 2.5 mg of phenylcapsaicin or matched placebo.
• Supplementation was administered 45 minutes before the CF session.
• The standardized CF session included a warm-up, weightlifting block, and WOD.
• The crossover design allowed each participant to serve as their own control.