Effects of sodium phosphate and caffeine loading on repeated-sprint ability

Abstract

The effects of sodium phosphate and caffeine supplementation were assessed on repeated-sprint ability. Using a randomised, double-blind, Latin-square design, 12 female, team-sport players participated in four trials: (1) sodium phosphate and caffeine, (2) sodium phosphate and placebo (for caffeine), (3) caffeine and placebo (for sodium phosphate) and (4) placebo (for sodium phosphate and caffeine), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (4 × 15 min quarters) with 6 × 20-m repeated-sprints performed once before (Set 1), at half-time (Set 2), and after end (Set 3). Total sprint times were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 1: P = 0.003; Set 2: d = -0.51; Set 3: P < 0.001; overall: P = 0.020), caffeine (Set 3: P = 0.004; overall: P = 0.033) and sodium phosphate (Set 3: d = -0.67). Furthermore, total sprint times were faster after sodium phosphate supplementation compared with placebo (Set 1: d = -0.52; Set 3: d = -0.58). Best sprint results were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 3: P = 0.007, d = -0.90) and caffeine (Set 3: P = 0.024, d = -0.73). Best sprint times were also faster after sodium phosphate supplementation compared with placebo (d = -0.54 to -0.61 for all sets). Sodium phosphate and combined sodium phosphate and caffeine loading improved repeated-sprint ability.

The Effect of Caffeine Supplementation on Trained Individuals Subjected to Maximal Treadmill Test

“…The caffeine stands out as the most ergogenic substance to be taken before practicing anaerobic exercises (high intensity and short duration), because it staves off fatigue and, thus, improves performance (Buck et al, 2015). However, the present study did not find physical performance improvement in CG in comparison to PG differently from other studies (Chen et al, 2015; Del Coso et al, 2016).…”

Practical Issues in Evidence-Based Use of Performance Supplements: Supplement Interactions, Repeated Use and Individual Responses

“…While the former may simply be a quirk of the statistical analysis in a small sample size, there may be some interaction that requires further investigation. Similar findings regarding the combination of caffeine and phosphate [42, 43] also merit additional research.…”

“…Effects of phosphate seen when fresh as well as fatiguedCaffeine and phosphate Kopec et al [42]Trained team sport athletes ( n  = 11 M)Crossover design to produce caffeine, phosphate, combined, and placebo trials6 mg/kg caffeine @ 60 min pre-exercise and/or 6 days @ 50 mg/kg/dayFFM sodium phosphate in split dosesWashout of 17 days between trialsTeam sport 6 × 20 s sprints Undertaken @ 0, 30, and 60 around a 2 × 30 min simulated team game circuitCaffeine: NoPhosphate: PerhapsInteraction: independent mechanism with possibly counteractive effectAlthough results failed to reach statistical significance, effect size and magnitude based analysis revealed that, compared with placebo, phosphate resulted in the fastest times for all sprints with moderate-large effect sizes and “likely” to “very likely” benefits. The beneficial effects of combined were smaller, and the effects of caffeine alone were minimal Buck et al [43]Recreationally trained team sport athletes ( n  = 12 F)Crossover design to produce caffeine), phosphate, combined, and placebo trials6 mg/kg caffeine @ 60 min pre-exerciseand/or 6 days @ 50 mg/kg/day FFM sodium phosphate in split dosesWashout of 17 days between trialsTeam sport 6 × 20 s sprints Undertaken @ 0, 30, and 60 around a 4 × 15 min simulated team game circuitCaffeine: NoPhosphate: YesInteraction: independent mechanism with no additive effectOverall results showed that combined and phosphate alone improved sprint times when fresh (set 1) and fatiguing (set 2 and 3) compared with placebo. Caffeine alone had small effects

BJ beetroot juice, BM body mass, ES effect size, FFM fat free mass, GI gastrointestinal, JSPT judo specific performance test, M male, F female, TT time trial

a Randomized, double-blind, placebo-controlled unless noted

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The Effects of Sodium Phosphate Supplementation on Physiological Responses to Submaximal Exercise and 20 km Cycling Time-Trial Performance

“…Sodium phosphate (SP) is a legal nutritional supplement that has been suggested to improve athletic performance (Currell et al, 2012). Several mechanisms have been proposed to explain this potential ergogenic effect, including an increase in resting erythrocyte 2, 3-diphosphoglycerate (2, 3-DPG) concentration (promoting oxygen offloading at the muscle via a reduction in oxyhaemoglobin affinity) (Bremner et al, 2002;Cade et al, 1984), an enhancement of myocardial contractility (Kreider et al, 1992), an increase in extracellular hydrogen phosphate (HPO4 -) concentration (facilitating hydrogen ion buffering) (Buck et al, 2015;Kopec et al, 2016), and an increase in the activity of various oxidative enzymes, such as phosphofructokinase and glyceraldehyde 3-phosphate dehydrogenase (Buck et al, 2013).…”