REF-831 · Etxebarria et al., 2013 · International Journal of Sports Physiology and Performance, Vol. · Paper · PubMed
Cycling Attributes That Enhance Running Performance After the Cycle Section in Triathlon
Twelve well-trained male triathletes rode two 1-h cycle trials at the same mean power (65% of maximal aerobic power, MAP): one with power varying from 40% to 140% MAP, as in a triathlon bike leg, and one at constant power. Each ride was followed by an outdoor 9.3-km time-trial run.
The run was 42 ± 37 s slower after the variable ride (35:32 vs 34:50 min:s), with most of the loss in the first half of the run. Higher lactate and RPE after the variable ride went with a larger run decrement; the power-profile test did not predict who lost most.
Participants
n=12 well-trained male triathletes (abstract: "Twelve well-trained male triathletes"): VO2peak 4.9 ± 0.5 L/min, body mass 73.5 ± 7.7 kg (mean ± SD).
Protocol
Preliminary tests: cycle VO2peak and maximal aerobic power (MAP) test; a power profile of 6 maximal efforts from 6 s to 10 min.
Two 1-h experimental rides on the bike, each averaging 65% MAP:
VAR: variable power ranging from 40% to 140% MAP (triathlon-specific distribution)
CON: constant power
Each ride was followed by an outdoor 9.3-km time-trial run.
A control 9.3-km run with no preceding exercise.
Blood lactate and rating of perceived exertion recorded after the rides.
Key Results
| After VAR cycling | After CON cycling | |
|---|---|---|
| 9.3-km run time (mean ± SD) | 35:32 ± 3:18 min:s | 34:50 ± 2:49 min:s |
| Difference (mean ± 90% CL) | 42 ± 37 s slower after VAR | — |
| Time lost in the run's first half | 35 ± 20 s (mean ± 90% CL) | — |
Higher blood lactate and RPE after 1 h of VAR cycling were moderately correlated with a larger run decrement (r = .51-.55; ± ~.40).
No clear association between the power-profile test and the decrement in run time after VAR compared with CON.
Authors' conclusion: riding with a very uneven power output probably hurts the 10-km run of a triathlon; training that lowers the physiological and perceptual responses to the ride should limit the negative effect.
Practical Application
**Does riding the bike leg unevenly cost me on the run even if my average watts are the same?In this crossover of twelve well-trained male triathletes, yes: a 1-h ride with power swinging between 40% and 140% of MAP slowed the following 9.3-km run by 42 ± 37 s compared with the same mean power held steady (35:32 vs 34:50), and most of the loss came in the first half of the run.** Ride the bike as evenly as the course allows; the surges are paid for on the run, not only in the bike split.
The riders who finished the variable ride with higher lactate and RPE lost the most on the run (r = .51-.55), so how hard the ride felt and how much lactate it produced mattered more than the rider's sprint or short-effort profile.
The power-profile test did not identify who copes with surges, so do not use a fresh short-effort profile to decide who can afford to ride aggressively.
Inference, not tested here: in a draft-legal race or on a hilly course some variability is unavoidable; the authors' suggestion is to train so that variable riding costs less, for example with bricks that include surges, but the paper did not test a training intervention.
Limitations
Twelve men; no women; well-trained, not elite.
One mean intensity (65% MAP) for 1 h and one variability pattern; a harder, longer or hillier ride may give a different decrement.
The ride was a controlled lab trial and the run was outdoors; no swim before the ride and no race conditions.
The 90% confidence limits are wide (42 ± 37 s), so the size of the effect for an individual is uncertain.
Correlations with lactate and RPE are moderate and cannot show cause.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level
crossover, n=12