Catecholamine, blood lactate and ventilatory responses to multi-cycle-run blocks.
OBJECTIVE
This study was designed to determine whether the physiological responses elicited during the run part of repeated bouts of cycle-run exercise are similar to those required during the run segment of a cycle-run succession. Thirteen male triathletes underwent four successive laboratory trials: 1) an incremental treadmill test, 2) an incremental cycle test, 3) 30 min of cycling followed by 20 min of running (C-R), and 4) five repeated bouts of 6 min of cycling and 4 min of running (X-CR). During the C-R and X-CR trials, venous blood samples were obtained to measure lactate, epinephrine and norepinephrine concentrations. During all trials, ventilatory data were collected every min using an automated breath-by-breath system.


RESULTS
The results showed that 1) the cardiorespiratory responses observed during running were similar in the X-CR and C-R trials, 2) the lactate concentration was similar in both trials, 3) the epinephrine concentration was greater (277.9 +/- 11.9 vs 169.8 +/- 86.7 pg x mL(-1), P < 0.025) in X-CR than in C-R, and 4) the norepinephrine concentration was similar in both trials, except at the first cycle-run succession (T1) of X-CR.


CONCLUSIONS
We concluded that 1) multi-block training is a good method to stimulate the specific adaptations required for the cycle-run succession, and particularly for the cycle-run transition, and 2) multi-block training seems to induce a greater catecholaminergic response, which may be due to a combination of an inherent effect of this type of training and the triathletes' relative lack of experience with it. In any case, the efficacy of the multi-block model needs to be more thoroughly evaluated over the course of a longer-term training program.
Hue
O
O
Laboratoire Sport, Performance, Santé, UPRES-EA, UFR-STAPS, Montpellier, France. HueO@wanadoo.fr
Le Gallais
D
D
Boussana
A
A
Galy
O
O
Chamari
K
K
Mercier
B
B
Prefaut
C
C
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D002302:Cardiac Output; D004837:Epinephrine / Q000097:blood*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D012119:Respiration; D012420:Running / Q000502:physiology*
D019344:Lactic Acid; D009638:Norepinephrine; D004837:Epinephrine