1. Neuromuscular and Metabolic Responses to High-Intensity Intermittent Cycling Protocols With Different Work-to-Rest Ratios.
- Author
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Nicolò, Andrea, Bazzucchi, Ilenia, Lenti, Mauro, Haxhi, Jonida, di Palumbo, Alessandro Scotto, and Sacchetti, Massimo
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QUADRICEPS muscle physiology ,ANALYSIS of variance ,ANTHROPOMETRY ,CARDIOPULMONARY system ,CARDIOPULMONARY system physiology ,CLINICAL trials ,STATISTICAL correlation ,CROSSOVER trials ,CYCLING ,ELECTROMYOGRAPHY ,EXERCISE physiology ,EXERCISE tests ,HEART rate monitoring ,LACTATES ,MUSCLE contraction ,NEUROPHYSIOLOGY ,PHYSICAL fitness ,REGRESSION analysis ,RESEARCH funding ,RESPIRATORY measurements ,STATISTICAL sampling ,SPORTS sciences ,STATISTICS ,T-test (Statistics) ,TIME ,DATA analysis ,COOLDOWN ,NEUROMUSCULAR system ,RANDOMIZED controlled trials ,REPEATED measures design ,OXYGEN consumption ,EXERCISE intensity ,DATA analysis software ,DESCRIPTIVE statistics - Abstract
Purpose: To investigate the effects of work-to-rest-ratio manipulation on neuromuscular and metabolic responses during 2 high-intensity intermittent training (HIT) protocols to exhaustion. Since different exercise durations were expected, the authors hypothesized that the protocol registering a longer duration would have a more pronounced effect on neuromuscular responses, while the other would challenge the cardiopulmonary system more. Methods: Thirteen competitive cyclists (age 19 ± 2 y) performed a preliminary incremental test to identify their maximal power output and 2 intermittent protocols to exhaustion (40:20s and 30:30s) at a fixed work rate of 135%Pmax interspersed by passive recovery. Surface electromyographic (sEMG) parameters (including muscle-fiber conduction velocity), cardiopulmonary parameters, and blood lactate concentration [La
-1 ] were recorded. Results: Time to exhaustion and total work were significantly higher for the 30:30s (38 ± 13 min, 495+161 kJ) than for the 40:20s (10 ± 3 min, 180 ± 51 kJ). No differences were found in sEMG parameters for the 2 protocols. Mean and peak values of VO2, heart rate, ventilatory parameters (except for the peak value of respiratory frequency), and [La-1 ] were significantly higher in the 40:20s than in the 30:30s. Conclusions: These results do not support the hypothesis that a longer time spent at high intensity has a more pronounced effect on neuromuscular responses, as no differences in EMG parameters were found in the 2 HIT protocols. Regarding metabolic responses, while the 40:20s led to maximal values of VO2 , [La-1 ], and ventilatory parameters within a few minutes, the 30:30s allowed maintenance of moderately high values for a considerably longer period, especially for [La-1 ] and ventilatory parameters. [ABSTRACT FROM AUTHOR]- Published
- 2014
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