Caffeine and anaerobic exercise performance: an exploration of caffeine’s effects on performance in young men and the influence of genotype on the variation in responses

INTERVENTION: Caffeine supplementation. Dose: 3 mg per kg of body weight The duration of administration: only on one occasion. Mode of administration: oral tablet. Wash out period between the caffeine and placebo conditions is from 4 to 7 days. The CYP1A2 genotype will be assessed using a buccal swab sample collected before the caffeine and placebo conditions. CONDITION: Exercise performance; ; Exercise performance Metabolic and Endocrine ‐ Normal metabolism and endocrine development and function Musculoskeletal ‐ Normal musculoskeletal and cartilage development and function PRIMARY OUTCOME: Primary Outcome 1: vertical jump height and power assessed using a countermovement jump on a force platform. ; [One hour post caffeine and placebo ingestion. ; ] Primary Outcome 2: barbell velocity in the bench press exercise assessed using linear position transducers. [One hour post caffeine and placebo ingestion. ] Primary Outcome 3: maximal number of repetitions in an upper‐body muscle endurance test.[One hour post caffeine and placebo ingestion. ] SECONDARY OUTCOME: Primary Outcome 4: mean and peak power in the Wingate test.[One hour post caffeine and placebo ingestion. ] Secondary Outcome 1: side‐effects to caffeine ingestion such as tachycardia, self‐reported by the participants. [Immediately post testing and upon waking up in the morning after testing. ] INCLUSION CRITERIA: The sample size will consist of resistance‐trained men. Resistance‐trained men will be defined as having a minimum of 6 months of resistance training experience with a minimum weekly training frequency of two times on most weeks.