Abstract
Despite the demonstrated evidence of the importance of eccentric contractions in sports performance, no research has evaluated the ergogenic effects of caffeine on this type of contraction means during flywheel exercises. Therefore, the aims of the present study were to compare the power outcomes, using different inertial loads, between caffeine and placebo conditions. Twenty-four young, healthy, and active men (age: 22.5 ± 4.8 years) took part in the study. A crossed, randomised double-blind design was used to analyse the effects of caffeine on lower limb power outcomes during a flywheel half-squat exercise. Participants completed four sets of eight all-out repetitions with a fixed three-minutes rest interval, and each set was performed using different inertial loads (i.e., 0.025, 0.050, 0.075 and 0.100 kg·m−2). Both the mean power (MP) and peak power (PP) in concentric (CON) and eccentric (ECC) movement phases at each inertial load were recorded after participants were administered either a caffeine supplement (6 mg·kg−1) or placebo (sucrose). Participants receiving a caffeine supplementation demonstrated improvements versus the placebo in total MP (MPtotal), as well as MP in CON phase (MPcon) and in ECC phase (MPecc) at each inertial load (22.68 to 26.53%; p < 0.01, effect size (ES) = 0.89–1.40). In addition, greater improvements with caffeine ingestion were obtained with respect to the placebo condition (18.79 to 24.98%; p < 0.01, ES = 1.03–1.40) in total PP (PPtotal), as well as PP in CON phase (PPcon) and in ECC phase (PPecc) at each inertial load. Thus, the supplementation of 6 mg·kg−1 caffeine may be considered to maximise on-field physical performance in those sports characterised by high demands of resistance.
Highlights
The majority of sports, team-based sports, are characterized by the need to apply the maximum force the athlete is able to produce over short time periods [1]
It has previously been suggested that power outcomes are perhaps the most important characteristic impacting sport success [2], showing that a superior ability to generate maximal power typically results in enhanced athletic performance [3]
This fact appears to be evidenced by the high correlation between power outcomes and crucial short-term high intensity actions in sport performance, such as changes of direction, acceleration, deceleration, sprints or jumps [4]
Summary
The majority of sports, team-based sports, are characterized by the need to apply the maximum force the athlete is able to produce over short time periods [1] In this sense, it has previously been suggested that power outcomes are perhaps the most important characteristic impacting sport success [2], showing that a superior ability to generate maximal power typically results in enhanced athletic performance [3]. It has previously been suggested that power outcomes are perhaps the most important characteristic impacting sport success [2], showing that a superior ability to generate maximal power typically results in enhanced athletic performance [3] This fact appears to be evidenced by the high correlation between power outcomes and crucial short-term high intensity actions in sport performance, such as changes of direction, acceleration, deceleration, sprints or jumps [4]. Along this line, increasing athletes’ power outcome levels could be an appropriate strategy to maximize on-field performance.
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