RESUMO
The objective of this study was to verify the agreement between pre-programmed and executed pacing during race walking and whether level of the athletes experience and performance influenced this relationship. Twenty-nine national and international race walkers participated in this study (14 males, 24.0±7.1 years old, and 15 females, 23.3±7.3 years old). Pre-programmed pacing for 10- and 20-km official walking races was self-selected via demonstrative pacing charts prior to races, while executed pacing was analyzed by a specialist investigator via an individual plot of current velocity versus distance. There was no agreement between pre-programmed and executed pacing (P=0.674). There was no association between the ability to match the pre-programmed pace with the executed pace and race walking experience or level of performance. Low- and high-performance athletes pre-programmed a similar pacing profile (P=0.635); however, high-performance athletes generally executed an even pacing strategy, while low-performance athletes generally adopted a positive pacing strategy (P=0.013). Race walkers did not faithfully match their pre-programmed with their executed pacing, and this seemed to be independent of previous experience and level of performance. High-performance athletes, however, tended to execute an even pacing strategy, even though this had not been pre-programmed.
Assuntos
Atletas , Desempenho Atlético/fisiologia , Resistência Física/fisiologia , Corrida/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The objective of this study was to verify the agreement between pre-programmed and executed pacing during race walking and whether level of the athletes experience and performance influenced this relationship. Twenty-nine national and international race walkers participated in this study (14 males, 24.0±7.1 years old, and 15 females, 23.3±7.3 years old). Pre-programmed pacing for 10- and 20-km official walking races was self-selected via demonstrative pacing charts prior to races, while executed pacing was analyzed by a specialist investigator via an individual plot of current velocity versus distance. There was no agreement between pre-programmed and executed pacing (P=0.674). There was no association between the ability to match the pre-programmed pace with the executed pace and race walking experience or level of performance. Low- and high-performance athletes pre-programmed a similar pacing profile (P=0.635); however, high-performance athletes generally executed an even pacing strategy, while low-performance athletes generally adopted a positive pacing strategy (P=0.013). Race walkers did not faithfully match their pre-programmed with their executed pacing, and this seemed to be independent of previous experience and level of performance. High-performance athletes, however, tended to execute an even pacing strategy, even though this had not been pre-programmed.
Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Resistência Física/fisiologia , Corrida/fisiologia , Desempenho Atlético/fisiologia , AtletasRESUMO
Analyzes of cardiac autonomic responses at the initial transient of exercise have been used for the investigation of the cardiovascular health. We evaluated the influence of aerobic fitness on HR and HRV responses at the onset of exercise. 25 male subjects (22.3±2.4 years) were divided into 2 groups: 'low aerobic fitness' (36.2±2.6ml.kg(-1).min(-1); n=10) and 'high aerobic fitness' (46.4±5.0ml.kg(-1).min(-1); n=15). The experimental session consisted of assessing the beat-to-beat HR at rest and during submaximal exercise. The autonomic responses at the onset of exercise were calculated by fitting the HR and HRV (rMSSD-index) curves during the initial 300s of exercise into a first-order exponential equation. The time constant of HR and of the rMSSD index (τonHR and τonrMSSD) were calculated for analysis. We observed lower values of τonrMSSD in the high aerobic fitness group compared to the low aerobic fitness group (26.8±5s vs. 38.0±18s, respectively; p=0.02). The τonHR (42.0±15 vs. 49.3±26s, p=0.38) for the groups showed no difference. Aerobic fitness partially influenced the autonomic responses during exercise, since individuals with higher fitness showed faster decreases in beat-to-beat HRV at the onset of exercise.
Assuntos
Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Aptidão Física/fisiologia , Adulto , Teste de Esforço , Humanos , Masculino , Fatores de Tempo , Adulto JovemRESUMO
Most studies regarding the impact of exercise intensity on cardiac autonomic regulation were conducted with athletes and used exercise intensities exceeding those recommended by position stands. We evaluated the influence of exercise intensity in a typical ACSM-aerobic session on 24-h cardiac autonomic modulation in sedentary subjects. Ten healthy sedentary subjects participated in the 3-day study. On 2 days, subjects performed a moderate- or high-intensity aerobic exercise session (MI, HI). The post-exercise protocol consisted of a continuous electrocardiographic recording for 1 h at the laboratory plus 23 h under ambulatory conditions. On the third day 24-h electrocardiographic recording was done without prior exercise (NPE). Heart rate (HR) and frequency-domain parameters (LF, HF) of heart rate variability were evaluated during the entire recovery period. Higher values of HR and lower values of HF and LF were observed throughout the first hour after the HI compared with the MI session. This difference was not observed after in ambulatory awake condition, but reappeared during sleep, when HF values after HI were lower compared with the NPE and MI (p<0.05). Even within the submaximal intensity-range of a typical exercise session, the intensity of exercise influences the post-exercise cardiac autonomic modulation in sedentary subjects.