The effect of multi-cycle-run blocks on pulmonary function in triathletes

Background. This study was designed to determined the pulmonary responses e licited by multi-cycle-run exercise in triathletes and to compare them to t hose elicited during a simple cycle-run succession. Methods. Twelve male triathletes underwent three successive laboratory tria ls: 1) an incremental cycle test, 2) 30 min of cycling followed by 20 min o f running (C-R), and 3) five repeated bouts of 6 min of cycling and 4 min o f 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 (DLCO). During all trials, v entilatory data were collected every minute using an automated breath-by-br eath system. Results. The results showed that: 1) the cardiorespiratory responses observ ed during running were greater in the X-CR trial for (V) over dot(E)/(V) ov er dot CO2 and HR,2) DLCO and DLCO/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 ca rdioventilatory responses than simple the cycle-run succession and 2) multi -block seems a good method to stimulate the specific adaptations required f or 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 thorou ghly evaluated over the course of a longer-term training programme.