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Published on: October 17, 2018
Physiological effects of constant versus variable power during endurance cycling
M A Liedl1, D P Swain, J D Branch
1Wellness Institute and Research Center, Old Dominion University, Norfolk, VA 23529-0196, USA.
Cycling with variable power (VP) does not increase physiological stress compared to constant power (CP). This finding is crucial for optimizing performance in cycling time trials without added exertion.
Area of Science:
- Exercise Physiology
- Sports Science
- Cycling Performance
Background:
- Theoretical research suggests variable power cycling may enhance time trial performance.
- The physiological stress associated with variable power cycling remains unquantified.
Purpose of the Study:
- To determine if variable power (VP) cycling induces greater physiological stress than constant power (CP) cycling.
- To compare physiological responses during VP and CP cycling at the same mean intensity.
Main Methods:
- Eight trained male cyclists completed three 1-hour ergometer trials.
- Trials included a self-paced maximal effort to determine mean power.
- Constant power (CP) and variable power (VP, +/- 5% of mean power) trials were conducted.
Main Results:
- No significant differences were observed in mean VO2, heart rate, blood lactate, or RPE between CP and VP trials.
- Mean VO2: CP 3.33 L/min, VP 3.26 L/min.
- Mean heart rate: CP 158 bpm, VP 159 bpm.
Conclusions:
- Variable power cycling (+/- 5%) does not impose additional physiological stress compared to constant power cycling.
- This holds true even during strenuous 1-hour efforts at approximately 78% of VO2max.
- Findings suggest VP cycling is a viable strategy for time trials without increased physiological strain.
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