Influence of isocapnic hyperpnoea on maximal arm cranking performance

Abstract

Isocapnic hyperpnoea has been shown to reliably produce fatigue of the diaphragm. The aim of the present study was to investigate whether incremental isocapnic hyperpnoea (IH(incr)) impairs the arm exercise performance and alters the breathing pattern during subsequent maximal incremental arm cranking. Nine healthy volunteers performed an arm cranking test with prior IH(incr) (AC(IH)) and without prior IH(incr) (AC(control)). Minute ventilation ( V(E)), tidal volume ( V(T)), breathing frequency ( f(b)), O(2) uptake ( VO(2)), CO(2) elimination ( VCO(2)), respiratory exchange ratio (RER) and end-tidal partial pressure of CO(2) ( P(ET)CO(2)) were measured at three different time intervals ( t(1): the average of the 3.30th min to the 6.30th min, t(2): 1 min before the end, t(3): peak value) and expressed as mean (SD). V(T) at t(1) and at t(3) was significantly ( P<0.05) lower during AC(IH) [AC(control): t(1): 1.3 (0.5) l, t(p): 1.9 (0.3) l; AC(IH): t(1): 1.1 (0.3) l, t(p): 1.6 (0.3) l]. f(b) at t(1) and t(2) was significantly ( P<0.05) higher during AC(IH) [AC(control): t(1): 23 (4) breaths min(-1), t(2): 42 (14) breaths min(-1); AC(IH): t(1): 27 (5) breaths min(-1), t(2): 48 (14) breaths min(-1)]. The maximal voluntary ventilation (MVV), measured before and immediately after the IH(incr), demonstrated a small but significant decrease from 157 (15) l min(-1) to 150 (14) l min(-1) ( P<0.05) after the IH(incr). In conclusion, rapid shallow breathing occurred during maximal arm cranking exercise after IH(incr). The alteration was irrespective of the workload and had already occurred at the start of exercise.

Increased ventilation does not impair maximal voluntary contractions of the elbow flexors

“…The effect of respiratory work on dynamic arm exercise is unclear. Volianitis et al (50) have reported improved rowing performance after a period of inspiratory muscle training, whereas van Houtte et al (49) reported no change in the endurance time of arm cranking exercise following a period of isocapnic hyperventilation. Furthermore, if the limit to performance is caused by blood flow interactions, the maximal isometric contraction of our study will have minimized any effect because intramuscular pressure makes such sustained contractions virtually ischemic (36,53).…”

“…Exercise performance and limb muscle contractile function can be impaired by a period of increased respiratory work, such as voluntary hyperventilation (30,52) (although for no difference see Refs. 11,40,49), breathing CO 2 mixtures (3,4,6), and increased inspiratory or expiratory resistance (22,25,29,35,38,47). Conversely, task performance benefits when the work of breathing is decreased by continuous positive airway pressure or proportional assist ventilation (13,22,33,35), or by breathing hyperoxic or HeO 2 mixtures (3,5,13).…”

Patients with acute spinal cord injury benefit from normocapnic hyperpnoea training

“…During 5 min of resting breathing, tidal volume and breathing frequency were measured with a spirometer (Ohmeda 5420, Cheshire, CT, USA) while P eT CO 2 was assessed using a CO 2 -analyser (Datascope 500, Paramus, NJ, USA). Normocapnic hyperpnoea was performed using a laboratory-developed device, described in detail by Markov et al (13) and Van houtte et al (14). In brief, the device consists of a re-breathing bag connected to a tube system and mouthpiece.…”

“…In a second phase the size of the hole could optimize the conditions (CO 2 /O 2 fraction) during normocapnic hyperpnea (NCh) training by making small changes in the amount of fresh air. This approach was validated in 2 previous studies (13,14). During normocapnic hyperpnoea, minute ventilation was displayed to the patient for feedback and a digital metronome paced breathing frequency.…”