The effects of sodium bicarbonate (NaHCO3) ingestion on high intensity cycling capacity

Ten healthy, non-cycling trained males (age: 21.2 +/- 2.2 years, body mass: 75.9 +/- 13.4kg, height: 178 +/- 6cm, [Vdot]O-2PEAK: 46 +/- 10ml center dot kg(1)center dot min(1)) performed a graded incremental exercise test, two familiarisation trials and six experimental trials. Experimental trials consisted of cycling to volitional exhaustion at 100%, 110% and 120% W-PEAK, 60min after ingesting either 0.3g center dot kg(1) body mass sodium bicarbonate (NaHCO3) or 0.1g center dot kg(1) body mass sodium chloride (placebo). NaHCO3 ingestion increased cycling capacity by 17% at 100% W-PEAK (327 vs. 383s; P=0.02) although not at 110% W-PEAK (249 vs. 254s; P=0.66) or 120% W-PEAK (170 vs. 175s; P=0.60; placebo and NaHCO3 respectively). Heart rate (P=0.02), blood lactate (P=0.001), pH (P<0.001), [HCO3 ], (P<0.001), and base excess (P<0.001) were greater in all NaHCO3 trials. NaHCO3 attenuated localised ratings of perceived exertion (RPEL) to a greater extent than placebo only at 100% W-PEAK (P<0.02). Ratings of abdominal discomfort and gut fullness were mild but higher for NaHCO3. NaHCO3 ingestion significantly improves continuous constant load cycling at 100% W-PEAK due to, in part, attenuation of RPEL.