Topical Sodium Bicarbonate: No Improvement in Blood Buffering Capacity or Exercise Performance.
Level 2 - randomized trial
Individual randomized crossover trials in human participants
PubMed 32575069 · doi:10.1123/ijspp.2019-0345
What was done
Two crossover experimental trials evaluated topical sodium bicarbonate lotion (PR lotion). In Study A, 10 recreationally active participants completed 2 trials: PR lotion (0.9036 g/kg NaHCO3 equivalent plus oral placebo) or oral NaHCO3 (0.3 g/kg plus placebo lotion) applied 90 minutes before cycling to exhaustion (30-s sprints at 120% peak power output, 30-s rest). Capillary blood pH, bicarbonate, and lactate were measured every 10 minutes over the 90-minute loading window and postexercise. In Study B, 10 cyclists/triathletes completed 2 trials: PR lotion or placebo lotion applied 30 minutes before 3 × 30-second maximal sprints (90-s recovery), with blood analyzed at baseline, preexercise, and postexercise.
What was found
In Study A, oral NaHCO3 significantly elevated blood pH and bicarbonate after 10 minutes and throughout recovery, whereas PR lotion produced no elevation (P < .001). Cycling time to exhaustion did not differ between PR lotion (349 [119] s) and oral NaHCO3 (363 [80] s; P = .697). In Study B, PR lotion produced no differences in blood parameters, mean power (P = .108), or peak power (P = .448) compared to placebo lotion.
Why it matters
Topical bicarbonate lotions are marketed to provide the ergogenic buffering benefits of sodium bicarbonate without gastrointestinal distress. These findings indicate the formulation does not penetrate sufficiently to alter systemic blood buffering capacity or improve sprint cycling performance.
Limits
Sample sizes were small (n = 10 per sub-study). The abstract does not specify participant sex or describe blinding methods. Only short-duration cycling sprint protocols were tested.
Cited by
- contradicts Sodium bicarbonate topical creams applied 30 to 60 minutes before exercise acutely improve high-intensity performance without causing GI distress.