Abstract
Proper sodium intake can help maintain plasma sodium levels, prevent plasma volume reduction, and improve performance, but specific guidelines on high dosages remain unclear. PURPOSE: The purpose of this study was to investigate the effect of a large dose sodium supplement before submaximal cycling on cardiovascular and thermoregulatory responses in a hot and humid environment. METHODS: Nine participants (6 males, 3 females; age = 22.22 ± 1.99 yrs; weight=79.93 ± 18.78 kg) completed both trials. Using a randomized, crossover design, participants consumed no supplement (control) at one trial and one with a large-dose sodium supplement (experimental, 810mg sodium/serving). After mixing the supplement in 532ml of water, participants drank 266ml 1 hour before the trial; consuming the rest within the first hour of cycling. During each visit, subjects cycled for 2-hours, maintaining their heart rate (HR) between 55-65% of their heart rate reserve in an environmental chamber set to 38°C and 60% relative humidity. Pre-, every 30-minutes during, and post-exercise, HR (bpm), blood pressure (mean arterial pressure [MAP]), and core temperature (Tc; °C). 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<05. RESULTS: Between conditions, there were no significant differences found (p>0.05) for any variables. No significant differences for any time point occurred for Tc. For time, pre-HR was significantly lower than all time-points during exercise (p<0.001). Pre-MAP was significantly lower than 30- (p=0.001), 60- (p=0.022), 90- (p=0.007), and 120-min (p=0.020) MAP. Pre-exercise average MAP in the supplement group was 88.65±6.27 and 88.17±4.94 in the control. 30-minutes into cycling, average MAP in the supplement group was 105.11 ± 8.84 vs. 101.7 ± 7.62 mmHg (control); 60min: experimental: 97.67 ± 5.91, control: 102.67 ± 10.17; 90min: experimental: 102.44 ± 11.04, control: 101.14 ± 8.43; and 120min: experimental: 98.68 ± 9.78, control: 100.17 ± 8.18 mmHg. CONCLUSION: A large dose sodium supplement consumed 1 hour before and during the first hour of exercise, does not negatively effect cardiovascular and thermoregulatory responses in recreationally trained adults.
Recommended Citation
Leale, Madison; Linhares, Abbie; Ott, Ryan; Robison, Kamiry; Kelly, Melani; and Draper, Shane
(2024)
"Impact of High-Dose Sodium Supplementation on Cardiovascular and Thermoregulatory Responses,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
Iss.
4, Article 127.
Available at:
https://digitalcommons.wku.edu/ijesab/vol14/iss4/127
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Health and Physical Education Commons, Medical Education Commons, Sports Sciences Commons