Physiological Responses to Running in Three Different Depths of Water at same Stride Frequency

Abstract

Many people utilize running in water as a form of exercise or rehabilitation. The physiological responses to exercising in different water depths are not fully understood. PURPOSE: To compare the responses of running at the same stride rate in three different water depths. METHODS: 8 subjects participated in a total four exercise sessions. Each subject underwent a deep water maximal exercise test to anchor the Borg 6–19 RPE scale. Subjects then participated in three exercise sessions. Each session consisted of running at a stride rate of 75 rpm's for 20 minutes, in waist deep (WD), chest deep (CD), and deep (DD) water depth levels. Deep water running was performed while wearing a floatation vest. Variables measured included heart rate (HR), rate of perceived exertion (RPE), whole blood lactic acid (LA), & thermal sensation (TS). HR and RPE were measured every 2 minutes. LA and TS were measured every 5 min. Data were analyzed using a repeated measures ANOVA with a Tukey's follow up test. RESULTS: Results for LA, TS are presented below as means and standard deviations.TableHR means were CD 119.7+15.6;WD 120.2+19.4;DD 128.5+13.2 bpm for each 20 min run. NSD (p>.05) was found among water depth for HR, RPE or TS. NSD (p>.05) was also found among water depths at the 5 min LA measurement, however a SD (p<05) was found at the 10, 15, and 20 min LA measurement. NSD was found between the WD, CD at any time measurement for LA. CONCLUSION: These results indicate that depth of water for running does not significantly impact HR, RPE, or TS. However the greater the depth of water in which exercise is performed, the greater the LA accumulation. When running in water the depth of the water should be considered for maximal benefit.