Key result
Bilateral lower extremity positive pressure during exercise increased end-exercise minute ventilation compared to pressure during recovery (53.3 vs 37.3 l/min; P<0.0001).
Why the study?
Does inflating bilateral lower extremity positive pressure cuffs during exercise alter minute ventilation and intracellular pH in healthy subjects?
RCT (n=12)
Randomized order
Does inflating bilateral lower extremity positive pressure cuffs during exercise alter minute ventilation and intracellular pH in healthy subjects?
Skeletal muscle hydrogen ion accumulation during exercise, accentuated by positive pressure cuffs, contributes to the exercise ventilatory response.
Muscle acidosis contributes to exercise ventilation; confirms H+ stimulus and extends mechanistic models in healthy subjects.
To determine whether skeletal muscle hydrogen ion mediates ventilatory drive in humans during exercise, 12 healthy subjects performed three bouts of isotonic submaximal quadriceps exercise on each of 2 days in a 1.5-T magnet for 31P-magnetic resonance spectroscopy (31P-MRS). Bilateral lower extremity positive pressure cuffs were inflated to 45 Torr during exercise (BLPPex) or recovery (BLPPrec) in a randomized order to accentuate a muscle chemoreflex. Simultaneous measurements were made of breath-by-breath expired gases and minute ventilation, arterialized venous blood, and by 31P-MRS of the vastus medialis, acquired from the average of 12 radio-frequency pulses at a repetition time of 2.5 s. With BLPPex, end-exercise minute ventilation was higher (53.3 +/- 3.8 vs. 37.3 +/- 2.2 l/min; P < 0.0001), arterialized PCO2 lower (33 +/- 1 vs. 36 +/- 1 Torr; P = 0.0009), and quadriceps intracellular pH (pHi) more acid (6.44 +/- 0.07 vs. 6.62 +/- 0.07; P = 0.004), compared with BLPPrec. Blood lactate was modestly increased with BLPPex but without a change in arterialized pH. For each subject, pHi was linearly related to minute ventilation during exercise but not to arterialized pH. These data suggest that skeletal muscle hydrogen ion contributes to the exercise ventilatory response.
No takes yet. Share an insight, caveat, or question.
Oelberg et al. (1998) conducted an RCT in Healthy (n=12). Bilateral lower extremity positive pressure cuffs inflated during exercise (BLPPex) vs. Bilateral lower extremity positive pressure cuffs inflated during recovery (BLPPrec) was evaluated on End-exercise minute ventilation (l/min) (p=<0.0001). Bilateral lower extremity positive pressure during exercise increased end-exercise minute ventilation compared to pressure during recovery (53.3 vs 37.3 l/min; P<0.0001).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: