Fig 1.
Participants ingested either ammonium chloride (0.15 g.kg-1, ACID) or placebo (0.15 g.kg-1, PLA) in four doses during the 24 h prior to the trial day.
An 8 min warm-up (5 min at 40% of peak power output, 3 min at 60% of peak power output) was followed by 10 x 2 min intervals at 80% of peak power output, interspersed with 1 min of active rest at 40% of peak power output, performed on a cycle ergometer. Timings of additional supplementation, venous blood and muscle biopsy samples and a post-exercise meal are shown prior to and following the high-intensity interval session.
Table 1.
Primer and TAQMAN probe sequences used for real-time PCR.
PDK4, pyruvate dehydrogenase kinase 4; PGC-1α, peroxisome proliferator-activated receptor-γ coactivator-1α CS, citrate synthase; Cyt c, cytochrome c oxidase, HKII, hexokinase II; GLUT4, glucose transporter-4; PGC-1β, peroxisome proliferator-activated receptor gamma coactivator-1β FOXO1, forkhead box O1.
Table 2.
Least squares means (and standard errors) for plasma pH (pH), bicarbonate (HCO3-) and lactate (Lac-) concentrations for placebo (PLA) and acidosis (ACID) trials at rest (REST), immediately after exercise (POST-EX) and 2 hours (2H) following exercise.
Fig 2.
Gene expression responses to a high-intensity interval exercise bout (10 x 2 min at 80% peak power output, 1 min @ 40% of peak power output) after the ingestion of ammonium chloride (ACID) or placebo (PLA).
The total ingestion of each supplement was 0.15 g·kg-1 on the day of the exercise protocol, equaling that consumed on the day prior to the trial. (a) PGC-1α, (b) citrate synthase, (C) cytochrome C; (d) PGC-1β. # significantly different to placebo at same time point (P < 0.05); * significantly different to same ingested substance at rest (P < 0.05). Values are least square means ± 95% confidence limits.
Fig 3.
Gene expression responses to a high-intensity interval exercise bout (10 x 2 min @ 80% peak power output, 1 min @ 40% of peak power output) after the ingestion of ammonium chloride (ACID) or placebo (PLA).
The total ingestion of each supplement was 0.15 g·kg-1 on the day of the exercise protocol, equaling that consumed on the day prior to the trial. (a) HKII, (b) GLUT4, (C) PDK4; (d) FOXO1. # significantly different to placebo at same time point (P < 0.05); * significantly different to same ingested substance at rest (P < 0.05). Values are least square means ± 95% confidence limits.