Mechanical Efficiency Is Lower After Cycling Compared To After Running In Trained Triathletes

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Justin Stewart (Creator)
Institution
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/
Advisor
Kevin Zwetsloot

Abstract: Triathlon involves swimming, cycling, and running. PURPOSE: To examine whether a 40-km cycling bout alters running economy (RE) and mechanical efficiency of running (ME) in trained triathletes. METHODS: Eight competitive triathletes (7 M, 1 F; 21.0±1.5 yrs; VO2max 59.2±7.6 mL?kg-1?min-1) with a minimum of one-year experience competing in triathlons. Subjects reported to the lab for 3 separate visits. At visit 1, subjects completed the informed consent, a VO2max test, anthropometric measures, and baseline performance testing [isometric squat (MVC) and countermovement jump (CMJ)]. During the 2nd visit, RE and ME were measured after subjects completed a 5-km treadmill run (R5K). For visit 3, RE and ME were measured after subjects completed 40-km of cycling (C40K). MVC, CMJ, and muscle glycogen values were measured before and after the exercise bout on visits 2 and 3. RESULTS: ME after C40K was significantly lower than ME after R5K (C40K: 48.4±5.7%, R5K: 53.7±3.5%; p=0.004). RE, blood lactate, respiratory exchange ratio, work, glycogen, CMJ, or MVC were not statistically different between C40K and R5K. CONCLUSION: The lower ME in running observed following cycling might be due to the combined effect of slightly higher blood lactate and RER values, and slightly lower external mechanical work performed.

Additional Information

Publication
Thesis
Stewart, J. (2016). Mechanical Efficiency Is Lower After Cycling Compared To After Running In Trained Triathletes. Unpublished Master’s Thesis. Appalachian State University, Boone, NC.
Language: English
Date: 2016
Keywords
Mechanical Work, Energy Expenditure, Respiratory Exchange Ratio, VO2, Lactate

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