Current knowledge of the physiological, biomechanical, and sensory effects of the cycle to run transition in the Olympic triathlon (1.5 km, 10 km, 40 km) is reviewed and implications for the training of junior and elite triathletes are discussed. Triathlon running elicits hyperventilation, increased heart rate, decreased pulmonary compliance, and exercise induced hypoxaemia. This may be due to exercise intensity, ventilatory muscle fatigue, dehydration, muscle fibre damage, a shift in metabolism towards fat oxidation, and depleted glycogen stores after a 40 km cycle. The energy cost (C_R) of running during the cycle to run transition is also increased over that of control running. The increase in C_Rvaries from 1.6% to 11.6% and is a reflection of triathlete ability level. This increase may be partly related to kinematic alterations, but research suggests that most biomechanical parameters are unchanged. A more forward leaning trunk inclination is the most significant observation reported. Running pattern, and thus running economy, could also be influenced by sensorimotor perturbations related to the change in posture. Technical skill in the transition area is obviously very important. The conditions under which the preceding cycling section is performed—that is, steady state or stochastic power output, drafting or non-drafting—are likely to influence the speed of adjustment to transition. The extent to which a decrease in the average 10 km running speed occurs during competition must be investigated further. It is clear that the higher the athlete is placed in the field at the end of the bike section, the greater the importance to their finishing position of both a quick transition area time and optimal adjustment to the physiological demands of the cycle to run transition. The need for, and current methods of, training to prepare junior and elite triathletes for a better transition are critically reviewed in light of the effects of sequential cycle to run exercise.

BENTLEY, D. J., L. R. MCNAUGHTON, D. THOMPSON, V. E. VLECK, and A. M. BATTERHAM. Peak power output, the lactate threshold, and time trial performance in cyclists. Med. Sci. Sports Exerc., Vol. 33, No. 12, 2001, pp. 2077–2081. To determine the relationship between maximum workload (Wpeak), the workload at the onset of blood lactate accumulation (WOBLA), the lactate threshold (WLTlog) and the Dmax lactate threshold, and the average power output obtained during a 90-min (W90-min) and a 20-min (W20-min) time trial (TT) in a group of well-trained cyclists. Nine male cyclists (V̇2max 62.7 ± 0.8 mL·kg−1·min−1) who were competing regularly in triathlon or cycle TT were recruited for the study. Each cyclist performed four tests on an SRM isokinetic cycle ergometer over a 2-wk period. The tests comprised 1) a continuous incremental ramp test for determination of maximal oxygen uptake (V̇2max) (L·min−1 and mL·kg−1·min−1); 2) a continuous incremental lactate test to measure Wpeak, WOBLA, WLTlog, and the Dmax lactate threshold; and 3) a 20-min TT and 4) a 90-min TT, both to determine the average power output (in watts). The average power output during the 90-min TT (W90-min) was significantly (P < 0.01) correlated with Wpeak (r = 0.91), WLTlog (r = 0.91), and the Dmax lactate threshold (r = 0.77, P < 0.05). In contrast, W20-min was significantly (P < 0.05) related to V̇2max (L·min−1) (r = 0.69) and WLTlog (r = 0.67). The Dmax lactate threshold was not significantly correlated to W20-min (r = 0.45). Furthermore, WOBLA was not correlated to W90-min (r = 0.54) or W20-min (r = 0.23). In addition, V̇2max (mL·kg−1·min−1) was not significantly related to W90-min (r = 0.11) or W20-min (r = 0.47). The results of this study demonstrate that in subelite cyclists the relationship between maximum power output and the power output at the lactate threshold, obtained during an incremental exercise test, may change depending on the length of the TT that is completed.

This study examined the consequences of performance in swim, cycle, and run phases on overall race finish in an elite “draft legal” Olympic distance (OD) triathlon. The subjects were 24 male athletes grouped by rank order into the top 50 % (n = 12) and bottom 50 % (n = 12) of the race population. Swimming velocity (m · s^-1), cycling speed (km · h^-1), and running velocity (m · s^-1) were measured at regular intervals using a global positioning system, chip timing system, and video analysis. Actual rank after each stage and overall was obtained from the race results and video analysis. The top 50 % athletes overall swam faster over the first 400 m of the swim phase (p > 0.05). Their swim ranking was lower (p < 0.01) than the bottom 50 % athletes after this stage. There were no significant differences in actual race position between the groups after the cycle. However, the bottom 50 % athletes after the swim stage cycled faster (p < 0.01) at 13.4 km of the cycle. Speed at 13.4 km of the cycle stage was inversely correlated (r = 0.60, p < 0.01) to running performance. Performance (rank and velocity) in the running stage was highly correlated with overall race result (r = 0.86 and - 0.53, respectively, both p > 0.01). It appears that inferior swimming performance can result in a tactic that involves greater work in the initial stages of the cycle stage of elite OD racing, and may influence subsequent running performance.