Acetazolamide impaired endurance performance at sea level (36 vs 48 min, P<0.05) but not at simulated altitude (20 vs 17 min, P=NS).
RCT (n=6)
Double-blind
Does acetazolamide impair muscle endurance at sea level and simulated altitude?
Acetazolamide impairs endurance exercise performance at sea level but not at simulated altitude, likely because the resulting metabolic acidosis is offset by a ventilatory-induced increase in arterial oxygen saturation at altitude.
Tasa de eventos absoluta: 36% vs 48%
valor p: p=<0.05
Acetazolamide can be taken at sea level to prevent acute mountain sickness during subsequent altitude exposure. Acetazolamide causes metabolic acidosis at sea level and altitude, and increases SaO2 (arterial oxygen saturation) at altitude. The aim of the present study was to determine whether acetazolamide impairs muscle endurance at sea level but not simulated altitude (4300 m for <3 h). Six subjects (20+/-1 years of age; mean+/-S.E.M.) performed exhaustive constant work rate one-leg knee-extension exercise (25+/-2 W) once a week for 4 weeks, twice at sea level and twice at altitude. Each week, subjects took either acetazolamide (250 mg) or placebo orally in a double-blind fashion (three times a day) for 2 days. On day 2, all exercise bouts began approx. 2.5 h after the last dose of acetazolamide or placebo. Acetazolamide caused similar acidosis (pH) in all subjects at sea level (7.43+/-0.01 with placebo compared with 7.34+/-0.01 with acetazolamide; P<0.05) and altitude (7.48+/-0.03 with placebo compared with 7.37+/-0.01 with acetazolamide; P<0.05). However, endurance performance was impaired with acetazolamide only at sea level (48+/-4 min with placebo compared with 36+/-5 min with acetazolamide; P<0.05), but not altitude (17+/-2 min with placebo compared with 20+/-3 min with acetazolamide; P = not significant). In conclusion, lack of impairment of endurance performance by acetazolamide compared with placebo at altitude was probably due to off-setting secondary effects resulting from acidosis, e.g. ventilatory induced increase in SaO2 for acetazolamide compared with placebo (89+/-1 compared with 86+/-1% respectively; P<0.05), which resulted in an increased oxygen pressure gradient from capillary to exercising muscle.
Fulco et al. (Mon,) reported a rct. Acetazolamide vs. Placebo was evaluated on Endurance performance at sea level (minutes) (p=<0.05). Acetazolamide impaired endurance performance at sea level (36 vs 48 min, P<0.05) but not at simulated altitude (20 vs 17 min, P=NS).