Efeitos agudos de uma sessão longa e curta de CrossFit® sobre a creatinaquinase, controle autonômico e fadiga muscular

Abstract

The main characteristic of CrossFit® is working in a constantly varied way and at high intensity. Studies show that aerobic and anaerobic stimulation leads to improvements in metabolic and musculoskeletal adaptations. Performance decline has been associated in athletes who have been exposed to high-intensity disabling activities without controlling the intervening variables. Therefore, understanding the psychophysical state of athletes is essential for planning training programs to maximize adaptations and performance. Objective: To compare the effects of a short (‘Fran’) and long (‘Cindy’) CrossFit® workout on creatine kinase, autonomic control and muscle fatigue in CrossFit® practitioners. Methods: 13 trained men (31.2 ± 3.2 years) with 5.72 ± 2 years of experience were recruited. Everyone performed two CrossFit® training sessions: ‘Fran’ and ‘Cindy’. Blood samples were collected to check creatine kinase (CK), heart rate variability (HRV) and vertical jump in the pretraining moments, immediately after (IA), 24h and 48h after. Results: A significant increase in CK was shown in ‘Fran’ 24h pre (p<0.05), while in ‘Cindy’ there was an increase IA and 24h after vs pre (p<0.05). HRV showed lower values (p<0.05) at the IA moment in both training sessions in relation to the time domain, but in the frequency domain it was only reduced (p<0.05) immediately after in ‘Cindy’. The vertical jump did not show significant differences between times and training. Conclusion: The present study showed that CK in both training sessions increased at specific moments evaluated, depending on the type of training. HRV reduced AI, except in the frequency domain for the shortest training session (‘Fran’). The vertical jump did not change until 48 hours after training, regardless of the stimulus.