Topical Sodium Bicarbonate: No Improvement in Blood Buffering Capacity or Exercise Performance.

Abstract

To assess the efficacy of a topical sodium bicarbonate (0.3g/kg body weight NaHCO3) application (PR lotion; Amp Human) on blood buffering capacity and performance in recreationally active participants (study A) and moderately trained athletes (study B). In Study A, 10 participants completed 2 experimental trials: oral NaHCO3 (0.3g/kg body weight + placebo lotion) or PR lotion (0.9036g/kg body weight + oral placebo) applied 90minutes prior to a cycling task to exhaustion (30-s sprints at 120% peak power output with 30-s rest). Capillary blood was collected and analyzed for pH, bicarbonate, and lactate every 10minutes throughout the 90-minute loading period and postexercise at 5, 10, and 15minutes. In Study B, 10 cyclists/triathletes completed 2 experimental trials, applying either PR or placebo lotion 30minutes prior to a cycling performance task (3 × 30-s maximal sprints with 90-s recovery). Capillary blood samples were collected at baseline, preexercise, and postexercise and analyzed as per study A. In Study A, pH and bicarbonate were significantly elevated from baseline after 10minutes in the oral NaHCO3 condition and throughout recovery compared with no elevation in the PR lotion condition (P < .001). No differences in cycling time occurred between PR lotion (349 [119]s) and oral NaHCO3 (363[80]s; P = .697). In Study B, no differences in blood parameters, mean power (P = .108), or peak power (P = .448) were observed between conditions. PR lotion was ineffective in altering blood buffering capacity or enhancing performance in either trained or untrained individuals.