Beneficial effects of oral and topical sodium bicarbonate during a battery of team sport-specific exercise tests in recreationally trained male athletes

Abstract

Objective: This study examined the effects of oral and topical (PR Lotion; Momentous) sodium bicarbonate (NaHCO₃) during a battery of team sport-specific exercise tests.

Method: In a block randomized, crossover, double-blind, placebo-controlled design, 14 recreationally trained male team sport athletes performed a familiarization visit and three experimental trials receiving: (i) 0.3 g·kg^-1 body mass (BM) NaHCO₃ in capsules + placebo lotion (SB-ORAL), (ii) placebo capsules +0.9036 g·kg^-1 BM PR Lotion (SB-LOTION), or (iii) placebo capsules + placebo lotion (PLA). Supplements were given ~120 min prior to the team sport-specific exercise tests: countermovement jumps (CMJ), 8 × 25 m repeated sprints and Yo-Yo Intermittent Recovery Level 2 (Yo-Yo IR2). Blood acid-base balance (pH, bicarbonate) and electrolytes (sodium, potassium) were measured throughout. Rating of perceived exertion (RPE) was recorded after each sprint and post-Yo-Yo IR2.

Results: Distance covered during the Yo-Yo IR2 was 21% greater for SB-ORAL compared with PLA (+94 m; p = 0.009, d = 0.64) whereas performance was only 7% greater for SB-LOTION compared with PLA (480 ± 122 vs. 449 ± 110 m; p = 0.084). Total completion time for the 8 × 25 m repeated sprint test was 1.9% faster for SB-ORAL compared with PLA (-0.61 s; p = 0.020, d = 0.38) and 2.0% faster for SB-LOTION compared with PLA (-0.64 s; p = 0.036, d = 0.34). CMJ performance was similar between treatments (p > 0.05). Blood acid-base balance and electrolytes were significantly improved for SB-ORAL compared with PLA, but no differences were observed for SB-LOTION. Compared to PLA, RPE was lower for SB-LOTION after the fifth (p = 0.036), sixth (p = 0.012), and eighth (p = 0.040) sprints and for SB-ORAL after the sixth (p = 0.039) sprint.

Conclusions: Oral NaHCO₃ improved 8 × 25 m repeated sprint (~2%) and Yo-Yo IR2 performance (21%). Similar improvements in repeated sprint times were observed for topical NaHCO₃ (~2%), but no significant benefits were reported for Yo-Yo IR2 distance or blood acid-base balance compared to PLA. These findings suggest that PR Lotion might not be an effective delivery system for transporting NaHCO₃ molecules across the skin and into systematic circulation, therefore further research is needed to elucidate the physiological mechanisms responsible for the ergogenic effects of PR Lotion.

Keywords: Supplements; Yo-Yo intermittent recovery test level 2; alkalosis; repeated sprint ability; team sports.

Figure 1.

Experimental schematic showing timings (minutes) and procedures for warm up and battery of team sport-specific exercise tests. BG = blood gas (pH, bicarbonate, hemoglobin, hematocrit, sodium, potassium), La = blood lactate, GI = gastrointestinal discomfort questionnaire, TA = treatment assignment questionnaire.

Figure 2.

Total distance covered during the Yo-Yo IR2 test. Bars represent mean values. Individual treatment differences depicted by symbol/line. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; * greater than PLA (p < 0.05). .

Figure 3.

(a, b) 8 × 25 m repeated sprint test average times (a) and total times (b). Bars represent mean values. Individual treatment differences depicted by symbol/line. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; * faster than PLA (p < 0.05).

Figure 4.

(a, b) Mean ± SD responses for blood acid–base balance (a, pH; b, bicarbonate). Bars represent mean values. Some SD error bars were removed for clarity. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; ^ elevated for SB-ORAL compared with SB-LOTION and PLA (p < 0.05).

Figure 5.

Mean ± SD for changes in plasma volume (PV) from baseline. Bars represent mean values. Some SD error bars were removed for clarity. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; ^ SB-ORAL higher than SB-LOTION and PLA, * SB-ORAL higher than PLA (p < 0.05).