Comparing Acute Effects of Caffeine Delivery Forms on Cross-Training Performance: A Randomized Placebo-Controlled Crossover Trial.

Caffeine mouth rinse (CMR) significantly improved countermovement jump (CMJ) performance compared to baseline, while other caffeine delivery forms did not.

• CMR produced a change of Δ: +3.5 cm in CMJ performance
• Effect size was Cohen's dunb: 0.51, indicating a moderate effect
• The improvement exceeded the estimated smallest worthwhile change (SWC) by approximately three-fold
• No changes in CMJ were observed with caffeine capsule (CC) or caffeine chewing gum (CCG)

No significant differences were found between any caffeine delivery forms in internal load measures.

• Rate of perceived exertion (RPE), maximum heart rate (HRmax), and mean heart rate (HRmean) showed no significant differences between conditions
• The inferential analysis revealed no significant main effects of the caffeine administration method on any measured outcomes
• Conditions compared included caffeine capsule (CC), caffeine chewing gum (CCG), caffeine mouth rinse (CMR), and a placebo group (PG)

No significant differences were found between caffeine delivery forms in the total number of repetitions performed during the 'Cindy' CrossFit protocol.

• The total number of repetitions was tracked at the end of the workout for all four conditions
• The inferential analysis revealed no significant main effects of caffeine administration method on repetition count
• This finding was consistent across all three caffeine delivery forms (CC, CCG, CMR) compared to placebo

The study employed a randomized, placebo-controlled, crossover design with fourteen trained male CrossFit participants.

• Participants had more than six months of continuous CrossFit training experience
• Sample characteristics: age 30.9 (±5.62) years, height 179 (±1.33) cm, weight 78 (±5.75) kg, BMI 24.3 (±1.33) kg·m-2
• A 7-day washout period was used before each crossover condition
• Participants were blinded to whether any delivery method contained caffeine
• Caffeine was administered 30 minutes prior to training to replicate real-world athlete pre-workout routines

The study used the 'Cindy' CrossFit protocol as the exercise intervention with CMJ measured pre- and post-intervention as the primary outcome.

• CMJ was measured before and after the intervention as the primary outcome measure
• RPE, heart rate, and number of repetitions were tracked at the end of the workout as secondary outcomes
• The protocol was designed to ensure ecological validity by mirroring typical athlete pre-workout routines