Background: This study was designed to determined the pulmonary responses elicited by multi-cycle-run exercise in triathletes and to compare them to those elicited during a simple cycle-run succession.
Methods: Twelve male triathletes underwent three successive laboratory trials: 1) an incremental cycle test, 2) 30 min of cycling followed by 20 min of running (C-R), and 3) five repeated bouts of 6 min of cycling and 4 min of running (X-CR). Before and 10 minutes after the third and fourth trials, the triathletes underwent lung function testing, especially spirometry and diffusing capacity testing for carbon monoxide (DL(CO)). During all trials, ventilatory data were collected every minute using an automated breath-by-breath system.
Results: The results showed that: 1) the cardiorespiratory responses observed during running were greater in the X-CR trial for VE/VCO2 and HR, 2) DL(CO) and DL(CO)/VA were significantly reduced after both trials, and 3) there were no significant changes in pulmonary volumes.
Conclusions: We concluded that 1) the multi-block trial elicited greater cardioventilatory responses than simple the cycle-run succession and 2) multi-block seems a good method to stimulate the specific adaptations required for the cycle-run succession, and particularly for the cycle-run transition. In any case, the efficacy of the multi-block model needs to be more thoroughly evaluated over the course of a longer-term training programme.