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

Figures & data

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). .

Table 1. Completion times (s) for individual sprints during the 8 × 25 m repeated sprint test.

	Sprint 1	Sprint 2	Sprint 3	Sprint 4	Sprint 5	Sprint 6	Sprint 7	Sprint 8
SB-ORAL	4.05 ± 0.26	4.10 ± 0.24	4.11 ± 0.21	4.14 ± 0.21	4.09 ± 0.17 *	4.12 ± 0.23 *	4.14 ± 0.22	4.12 ± 0.21 *
SB-LOTION	4.03 ± 0.26	4.07 ± 0.31	4.14 ± 0.29	4.11 ± 0.29	4.10 ± 0.25 *	4.12 ± 0.25 *	4.15 ± 0.28	4.13 ± 0.21 *
PLA	4.06 ± 0.26	4.13 ± 0.24	4.18 ± 0.24	4.20 ± 0.20	4.20 ± 0.21	4.23 ± 0.21	4.23 ± 0.21	4.23 ± 0.15

Values are presented as mean ± SD. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; * faster 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).

Table 2. Blood lactate and electrolyte response throughout the battery of team sport-specific exercise tests.

	Baseline	Pre-warm-up	Pre-test	Pre-sprints	Post-sprints	Pre-Yo-Yo IR2	Post-Yo-Yo IR2
SB-ORAL
BLa^− (mmol·L^−1)	1.16 ± 0.15	1.32 ± 0.33	2.63 ± 0.81	2.35 ± 0.46	7.13 ± 1.78	4.09 ± 1.93	13.87 ± 2.90 ^
Na^+ (mmol·L^−1)	135 ± 2	137 ± 2 *	137 ± 2 *	-	-	138 ± 3 *	139 ± 2 *
K^+ (mmol·L^−1)	4.4 ± 0.5	3.9 ± 0.3 *	4.0 ± 0.5	-	-	3.9 ± 0.4	3.8 ± 0.4
SB-LOTION
BLa^− (mmol·L^−1)	1.21 ± 0.28	1.36 ± 0.45	2.71 ± 1.06	2.41 ± 0.74	7.02 ± 2.43	3.82 ± 2.36	11.22 ± 2.48
Na^+ (mmol·L^−1)	135 ± 2	136 ± 2	136 ± 2	-	-	136 ± 3	137 ± 3
K^+ (mmol·L^−1)	4.3 ± 0.2	4.2 ± 0.4	4.2 ± 0.4	-	-	4.0 ± 0.4	3.9 ± 0.3
PLA
BLa^− (mmol·L^−1)	1.15 ± 0.28	1.31 ± 0.24	3.08 ± 1.68	2.55 ± 1.28	6.01 ± 2.45	4.20 ± 2.42	11.45 ± 2.55
Na^+ (mmol·L^−1)	134 ± 1	135 ± 2	135 ± 1	-	-	135 ± 2	136 ± 2
K^+ (mmol·L^−1)	4.3 ± 0.4	4.3 ± 0.3	4.2 ± 0.4	-	-	4.3 ± 0.7	4.2 ± 0.8

Values are presented as mean ±SD. Blood electrolytes were not measured pre- or post-sprints. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; * difference compared with PLA, ^ difference 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).

Table 3. RPE (au.) after each of the 8 × 25 m repeated sprints and post-Yo-Yo IR2.

	Sprint 1	Sprint 2	Sprint 3	Sprint 4	Sprint 5	Sprint 6	Sprint 7	Sprint 8	Yo-Yo IR2
SB-ORAL	10.7 ± 3.0	11.3 ± 2.8	12.5 ± 2.8	13.4 ± 2.6	14.0 ± 2.4	14.9 ± 2.2 *	15.5 ± 2.1	16.6 ± 2.0	19.0 ± 1.1
SB-LOTION	10.5 ± 3.1	11.7 ± 2.8	12.4 ± 2.8	13.1 ± 2.7	13.9 ± 2.3 *	14.6 ± 2.0 *	15.7 ± 1.9	16.1 ± 2.2 *	19.2 ± 0.8
PLA	10.8 ± 3.2	11.6 ± 3.0	12.7 ± 2.6	14.1 ± 2.3	14.8 ± 2.0	15.8 ± 1.6	16.4 ± 1.5	17.5 ± 1.2	19.1 ± 0.9

Values are presented as mean ± SD. RPE values were measured using the 6–20 Borg scale. SB-ORAL = oral sodium bicarbonate, SB-LOTION = topical sodium bicarbonate, PLA = placebo; * lower than PLA (p < 0.05).

Data availability statement

The datasets used and/or analyzed during the present study are available from the corresponding author on reasonable request https://shura.shu.ac.uk/.