Purpose: To investigate the gender differences in the effect of increasing workload level and thus of an increasing metabolic drive to ventilation on the degree of coordination between breathing and cycling rhythms.
Methods: Twenty-one men and 21 women cycled on an electromagnetically braked ergometer while breathing through a pneumotachograph at workloads corresponding to 55, 75, and 95% of V0(2peak) (WL1, WL2, and WL3). Leg movements, respiratory parameters, and heart rate were continuously recorded. The degree of coordination (%coord) was quantified as the percentage of breaths starting during the same phase of leg movement.
Results: In men, %coord increased with increasing exercise intensity (WL1: mean +/- SE = 18.8 +/- 2.6%, WL2: 30.9 +/- 4.9%, WL3: 40.9 +/- 5.6%), whereas in women exercise intensity had no influence on %coord (WL1: 25.0 +/- 5.0%, WL2: 29.7 +/- 5.1, WL3: 31.7 +/- 4.7%). There were no gender differences in breathing pattern during high metabolic demands. A major effect on %coord came from the regularity of the breathing rhythm, whereas cycling frequency, fitness level, or cycling experience exerted no influence.
Conclusions: The present study demonstrates that the effect of exercise intensity on the occurrence of coordination between breathing and cycling rhythms differs between men and women.