Abstract
BackgroundTo investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon.Methodology/Principal FindingsWe recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg) for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage.ResultsJump height (from 30.3±5.0 to 23.4±6.4 cm; P<0.05) and leg power output (from 25.6±2.9 to 20.7±4.6 W · kg−1; P<0.05) were significantly reduced after the race. However, handgrip maximal force was unaffected by the race (430±59 to 430±62 N). Mean dehydration after the race was 2.3±1.2% with high inter-individual variability in the responses. Blood myoglobin and creatine kinase concentration increased to 516±248 µg · L−1 and 442±204 U · L−1, respectively (P<0.05) after the race. Pre- to post-race jump change did not correlate with dehydration (r = 0.16; P>0.05) but significantly correlated with myoglobin concentration (r = 0.65; P<0.001) and creatine kinase concentration (r = 0.54; P<0.001).Conclusions/significanceDuring a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon.
Highlights
The triathlon is an endurance sport activity that combines phases of swimming, cycling and running
Suzuky et al [3] found that jump height during squat and countermovement jumps (CMJ) significantly decreased after an Iron triathlon along with a reduction in the maximal isometric strength of the knee extensors
Urine pH and bilirubin concentration remained unchanged after the race. The aim of this investigation was to determine the sources of muscle fatigue experienced by triathletes during a half-iron distance race
Summary
The triathlon is an endurance sport activity that combines phases of swimming, cycling and running. Independent of the distance, the triathlon is one of the most fatiguing exercise activities since it combines long duration (from 1 h 50 min in the Olympic distance to more than 14 hours in the Ironman distance) with high exercise intensity [1]. Margaritis et al [2] found a decreased capacity to generate force in the knee extensor and flexor muscles after a half-iron triathlon. Suzuky et al [3] found that jump height during squat and countermovement jumps (CMJ) significantly decreased after an Iron triathlon along with a reduction in the maximal isometric strength of the knee extensors. To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
