Autonomic nervous system (ANS) recovery following two types of supramaximal exercise: 1 Wingate (1W) and sprint interval exercise (SIE)

The ANS is an important regulator of the cardiovascular system. ANS recovery following 2 types of supramaximal exercise (1W and SIE) was studied using baroreceptor sensitivity (BRS). SIE consists of 4 Wingates interspersed with 4 min. of light cycling. The RR intervals (RRi) and blood pressure (BP) of nine males, aged 18–22 yrs. were monitored during 10 min. of supine rest and 8 min. of standing after 50 min. of supine rest before exercise (PRE); after 50 min. of supine rest after exercise (PST1); and 1 h. 50 min. after exercise (PST2). Baroreceptor sensitivity (BRS:ms/mm. Hg) was determined as a ratio of 3 consecutive increases/decreases in the RRi and systolic BP. Supine BRS was significantly lower (p<0.001) at PST1 (6.771±1.120) than PRE (15.289±1.809) and PST2 (11.273±1.333). BRS at PST2 returned to PRE values after 1W, but remained lower after SIE (p=0.02). Standing BRS was significantly less (p<0.001) at PST1 (2.272±0.482) than PRE (5.599±0.770) or PST2 (3.713±0.620) and returned to PRE values after 1W, but not after SIE (p=0.01). We conclude that ANS takes longer than 1 h. to recover following supramaximal exercise, and recovery is longer after SIE than 1W. This study was supported by NSERC.