Constant versus variable-intensity during cycling: effects on subsequent running performance

Abstract

The aim of this study was to investigate the metabolic responses to variable versus constantintensity (CI) during 20-km cycling on subsequent 5-km running performance. Ten triathletes, not only completed one incremental cycling test to determine maximal oxygen uptake and maximal aerobic power (MAP), but also three various cycle-run (C-R) combinations conducted in outdoor conditions. During the C-R sessions, subjects performed first a 20-km cycletime trial with a freely chosen intensity (FCI, ~80% MAP) followed by a 5-km run performance. Subsequently, triathletes were required to perform in a random order, two C-R sessions including either a CI, corresponding to the mean power of FCI ride, or a variable-intensity (VI) during cycling with power changes ranging from 68 to 92% MAP, followed immediately by a 5-km run. Metabolic responses and performances were measured during the C-R sessions. Running performance was significantly improved after CI ride (1118 ± 72 s) compared to those after FCI ride (1134 ± 64 s) or VI ride (1168 ± 73 s) despite similar metabolic responses and performances reported during the three cycling bouts. Moreover, metabolic variables were not significantly different between the run sessions in our triathletes. Given the lack of significant differences in metabolic responses between the C-R sessions, the improvement in running time after FCI and CI rides compared to VI ride suggests that other mechanisms, such as changes in neuromuscular activity of peripheral skeletal muscle or muscle fatigue, probably contribute to the influence of power output variation on subsequent running performance.

Longitudinal Changes in Response to a Cycle-Run Field Test of Young Male National “Talent identification” and Senior Elite Triathlon Squads

“…First of all, we used a cycling section at the intensity corresponding to the Th vent that lasted 30 min as this has been shown to produce a modified cardiorespiratory response from that observed during an isolated control run (10-11, 16-18, 20). Secondly, we chose a 3-km time-trial to assess running performance because said distance has been both implemented before in specific-T2 tests (3)(4) and demonstrated to be sufficient to determine the possible effects of neuromuscular fatigue on performance (30).…”

Effects of magnitude and frequency of variations in external power output on simulated cycling time-trial performance

“…To simplify the examination of pacing strategy on performance, the present and other studies compared effects of highly regular, alternately high and low power profiles with those from equivalent, but constant, mean external power outputs. A similar approach has occurred in investigations of physiological response (Lepers, Theurel, Hausswirth, & Bernard, 2008; and performance consequences of variable-power strategies (Bernard et al, 2007;Suriano, Vercruyssen, Bishop, & Brisswalter, 2007) and results have been equivocal. However, the highly regular periods and amplitudes of variation presented in the present and other studies are unlikely to represent the periods and amplitudes of variation that occur during self-paced trials (Jobson, Passfield, Atkinson, Barton, & Scarf, 2009).…”

Age-Related Decline in Olympic Triathlon Performance: Effect of Locomotion Mode

“…During the last decade, triathlon, involving successive swimming, cycling, and running sessions, has become one the most popular multidisciplinary event. Studies focusing on factors affecting performance during a triathlon have clearly identified differences with single performance, indicating that the effect of previous locomotion mode on subsequent exercise was the main factor explaining changes in performance (Bentley, Millet, Vleck, & McNaughton, 2002;Bernard et al, 2007;Hausswirth & Lehénaff, 2001). Therefore the adaptation of triathletes must be considered as unique and relatively specific to the constraints activity (race profile, swim-cycle and cycle-run transitions, intensity, and exercise duration).…”