Effects of different protocols of hydration on cardiorespiratory parameters during exercise and recovery

Abstract

IntroductionHydration plays a key role in the physiological maintenance required by exercise.ObjectiveTo evaluate the behavior of heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, pulse oxygen saturation (SpO2) and respiratory rate (RR) of young people during and after prolonged physical exercise, with and without the intake of water or isotonic solution.Method31 young individuals (21.63 ± 1.86 years) were subjected to a four-step protocol with a 48-hour interval between each step, namely: i) a test to determine the incremental load used in subsequent steps, ii) a control protocol without hydration (CP), iii) an experimental protocol with water intake (PE1), iv) an experimental protocol with ingestion of isotonic (PE2). The protocols consisted of 10 min rest, 90 min of exercise on a treadmill at 60% of VO2peak and 60 min of recovery. The parameters HR, SBP, DBP, RR and SPO2 were measured at rest, at 30, 60 and 90 min of exercise, with the exception of RR; and at 1, 3, 5, 7, 10, 20, 30, 40, 50 and 60 min of recovery. The two-factor analysis of variance for repeated measures model was used for analysis (p<0.05).ResultsThere was a moment effect for all variables in exercise (p<0.001), however, no effect was observed between the protocols (SBP, p=0.998; DBP, p=0.897; SpO2, p=0.077, HR=0.281) and in the interaction moment and protocol (SBP, p=0.058; DBP, p=0.191 and SpO2, p=0.510, HR=0.496). In recovery there was also a moment effect for all variables analyzed (p<0.001). There was no effect among protocols for SBP (p=0.986), DBP (p=0.536) and RR (p=0.539), however in the SpO2 (p=0.001) and HR (p=0.033) variables, effects were observed between the protocols. Regarding the moment and protocol interaction, an effect was observed for HR (SBP, p=0.431; DBP, p=0.086; SpO2, p=0.445, RR, p=0.147, HR, p=0.022).ConclusionFor the type of exercise performed, both the water and the isotonic solution influenced the behavior of cardiorespiratory parameters, and independent of the type of hydration given the behavior of the parameters studied was similar.

The Role of Water Intake on Cardiac Vagal Reactivation after Upper-body Resistance Exercise

“…The authors observed lower oxygen saturation levels and higher HR during recovery on control visits compared with those involving water or isotonic intake, and no protocols demonstrated an effect on blood pressure or respiratory rate. These studies [43,45] are consistent with the results of the present study, in which higher CVI values during recovery were obtained after 500 ml of water intake compared with 50 ml. Although our study was not aimed at verifying the physiological mechanisms of the effects of drinking on cardiac autonomic reactivation, based on other studies, it can be speculated that the observed effect may be related to either gastrovascular reflex (gastric distention) [39,44] or osmotic factors [13,29].…”

“…Drinking water has been shown to induce cardiovascular and autonomic responses [6,14,25,40]. Previous studies found that hydration accelerates post-exercise cardiovascular recovery after a single session of submaximal aerobic exercise [43,45]. Vianna et al [45] reported that drinking 500 ml of water immediately after 30 min of cycling exercise at a workload representing 80 % of anaerobic threshold accelerated post-exercise cardiac vagal reactivation in 10 healthy subjects, suggesting that hydration after aerobic exercise may be an effective strategy for increasing postexercise cardiovascular safety.…”

“…This simple and highly reliable protocol [10] has been used in various physiological and clinical studies [17,28,30,34,36,37,45]. Previous studies have been performed to verify the influence of water intake on post-exercise cardiac autonomic control after an aerobic exercise session [43,45]. Vianna et al [45] submitted 10 subjects (8 men) to a 30-min cycling exercise at 80 % of anaerobic threshold and, using 4sET, verified higher cardiac vagal activity at 30-min post-exercise when 500 ml of water was ingested compared with 50 ml of water, without effects on HR or blood pressure.…”

“…Vianna et al [45] submitted 10 subjects (8 men) to a 30-min cycling exercise at 80 % of anaerobic threshold and, using 4sET, verified higher cardiac vagal activity at 30-min post-exercise when 500 ml of water was ingested compared with 50 ml of water, without effects on HR or blood pressure. More recently, Vanderlei et al [43] compared 3 protocols with or without drinking water or isotonic solution administered in 10 equal portions at regular 15-min intervals over 90 min of treadmill aerobic exercise and 60 min of recovery. The authors observed lower oxygen saturation levels and higher HR during recovery on control visits compared with those involving water or isotonic intake, and no protocols demonstrated an effect on blood pressure or respiratory rate.…”

Influence of the hydration on autonomic modulation and cardiorespiratory parameters of coronary heart disease patients submitted to a cardiovascular rehabilitation session: crossover clinical trial protocol

“…In this sense, different strategies to accelerate the autonomic and cardiovascular system recovery after physical exercise practice have been studied on literature [15][16][17][18][19][20] , and water intake is one of than [21][22][23] . Studies that investi-gated the effects of water intake associated to physical exercise, pointed that this strategy was able to attenuate cardiovascular 18,24 and autonomic [20][21][22][23] alterations promoted by the thermic stress as a result of physical exercise and to promote a faster recovery of the organism 18,[20][21][22][23] .…”