Shorter CWR cycling tests as proxies for longer tests in highly trained cyclists

Severe-intensity constant work rate (CWR) cycling tests simulate the
high-intensity competition environment and are useful for monitoring
training progression and adaptation, yet impose significant physiological
and psychological strain, require substantial recovery, and may disrupt
athlete training or competition preparation. A brief, minimally fatiguing
test providing comparable information is desirable. Purpose: To determine
whether physiological variables measured during, and functional decline in
maximal power output immediately after, a 2-min CWR test can act as a
proxy for 4-min test outcomes. Methods: Physiological stress (V̇O2
kinetics, heart rate, blood lactate concentrations ([La-]b)) was monitored
and performance fatigability was estimated (as pre-to-post-CWR changes in
10-s sprint power) during 2- and 4-min CWR tests in 16 high-level cyclists
(V̇O2peak=64.4±6.0 ml∙kg-1∙min-1). The relationship between the 2- and
4-min CWR tests and the physiological variables that best relate to the
performance fatigability were investigated. Results: The 2-min CWR test
evoked a smaller decline in sprint mechanical power (32% vs. 47%,
p<0.001). Both the physiological variables (r=0.66-0.96) and sprint
mechanical power (r=0.67-0.92) were independently and strongly correlated
between 2- and 4-min tests. Differences in V̇O2peak and [La-]b in both CWR
tests were strongly associated with the decline in sprint mechanical
power. Conclusion: Strong correlations between 2- and 4-min
severe-intensity CWR test outcomes indicated that the shorter test can be
used as a proxy for the longer test. A shorter test may be more practical
within the elite performance environment due to lower physiological stress
and performance fatigability and should have less impact on subsequent
training and competition preparation.