Purpose:
The aim of this study was to evaluate the impact of training with added respiratory dead space volume (ARDSV) on changes in a breathing pattern and cycling efficiency.

Methods:
Twenty road cyclists were equally divided into an experimental (E) and control (C) group. All of them were involved in a training program that included endurance training (at moderate intensity) and interval training (at maximal intensity). During semi-weekly endurance training, ARDSV (1000cm3 tube) was introduced in the experimental group. Respiratory parameters, including, among others, oxygen uptake (VO₂), carbon dioxide excretion (VCO₂), end-tidal partial pressure of carbon dioxide (PETCO₂), pulmonary ventilation (VE), tidal volume (TV) and total work done during the tests (W), were measured before and after the experiment by a progressive and continuous test.

Results:
Higher PETCO₂ and TV in both groups during the progressive and continuous tests were observed. VCO₂ increased in group E during continuous test, while for group C only in the first four minutes of the test. VO₂ and VE increased only in group E during submaximal and maximal exercise. Total work increased during the continuous test in both groups (significantly higher in group C than E). However, total work during the progressive test increased only in group E.

Conclusions:
Training with ARDSV improved exercise capacity at maximal effort and was associated with an increase in maximal oxygen uptake. On the other hand, this type of training lead to a decrease in cycling efficiency, reducing in effect the benefits associated with an increase in VO₂max and reducing the ability to perform submaximal effort.