Abstract
Sodium intake plays a major role in maintaining fluid-electrolyte balance and cardiovascular function during exercise. PURPOSE: To evaluate how a high-dose sodium supplement impacts heart rate (HR), mean arterial pressure (MAP), and ratings of perceived exertion (RPE). METHODS: Twenty recreationally active participants (15 males, 5 females; age = 23.4 ± 2.8) completed a 2-h bout of cycling in an environmental chamber (37.3℃, 59.1 ± 4.4% relative humidity) on two occasions separated by > 7 days. Participants were randomly provided a large-dose sodium supplement (810mg/532 mL of water) before one trial. Participants were instructed to consume 266mL 1-h pre-trial and consumed the remaining 266mL within the first hour of cycling. Participants were instructed to maintain their HR between 55-65% of their HR reserve. Pre- and every 30-min during, HR (bpm), blood pressure (MAP), and RPE were collected. Paired samples t-tests and repeated measures ANOVA were used to analyze differences between condition and time. Descriptive statistics (mean ± standard deviation) were calculated for all data. Significance level was set at p < 0.05. RESULTS: Between conditions, there were no significant differences found (p > 0.05) for any variables. For time, pre-HR was significantly lower than all time-points during exercise (p < 0.001). Average HR pre-trial was 66.7 ± 7.4 bpm (supplement) and 70.9 ± 8.7 bpm (control). At 120-min of cycling, HR was 145.7 ± 9.1 bpm (supplement) and 136.7 ± 19.9 bpm (control). CONCLUSION: Cardiovascular responses do not appear to be significantly altered when cycling in a hot, humid environment after consuming a supplement with 810mg of sodium. Although heart rate increased over time in both conditions, the control group exhibited a lower heart rate at the end of exercise, suggesting acute, high-doses of sodium may exert additional cardiovascular strain that remains within safe limits.
Recommended Citation
Ott, Ryan; Caruso, Abram; Hatch, Sterling; McQuinn, Melanie; Kelly, Melani; Creer, Andrew; and Draper, Shane
(2025)
"High-Dose Sodium Supplementation on Cardiovascular Responses while Cycling in the Heat,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
Iss.
5, Article 67.
Available at:
https://digitalcommons.wku.edu/ijesab/vol14/iss5/67
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