Project(past)s | SangHoon Yoon

Repeated sprint exercise

Mon, 11 Oct 2021 00:00:00 +0000

It is postulated that females' lower fatigue responses-induced by high-intensity exercise is attributed to the lower mechanical work performed compared to males. The objective of this study was to compare peripheral (quadriceps twitch force, muscle deoxygenation) and central (voluntary activation) fatigue mechanisms between the sexes during repeated all-out cycling. The novel aspect of this work was that we covaried for total mechanical work and corrected the NIRS data for subcutaneous adipose tissue thickness, facilitating intersubject comparison. We found that females showed greater fatigue resistance in the locomotor muscles: lower muscle deoxygenation, peripehral fatigue, as well as smaller reduction in maximal rate of force development (related to excitation-contraction coupling). We speculate that this is ultimately due to sex differences in muscle metabolism related to their muscle fiber type I/II. Manuscript is currently in preparation and was presented at CSEP conference.

Yoon S, Cederbaum LA, Côté JN. Females show less decline in contractile function than males after repeated all-out cycling. Appl Physiol Nutr Metab. 2023;apnm-2023-0184.

Cederbaum LA, Yoon S, Côté JN. Males and females have similar neuromuscular coordination strategies of the quadriceps during fatiguing repeated all-out cycling. Front Sports Act Living. 2023;5:1248303.

Yoon, S., Cederbaum, A. L., & Côté, J. N. (2021). Does adjusting for mechanical work affect sex differences in peripheral and central fatigue during repeated sprints? CSEP Annual General Meeting - Zooming into the Future: Exercise Science in the Virtual Age. Oral presentation.

Repetitive pointing task

Mon, 11 Oct 2021 00:00:00 +0000

Female workers are at a greater risk for neck/shoulder musculoskeletal disorders. This project compared repetitive task-induced changes in muscular parameters between females and males. The outcome measures included muscle activity (via EMG), trapezius oxygenation (via NIRS), and muscle swelling (via ultrasonography). We found that females showed comparable fatigaiblity, oxygenation and majority EMG responses as males; however, females showed greater anterior deltoid activation and an absence of deltoid activation modulation with fatigue. For more details, please refer to studies below:

Yoon, S., Bailey, C. A., Cohen, N. R., & Côté, J. N. (2021). Changes in muscle activation, oxygenation, and morphology following a fatiguing repetitive forward reaching task in young adult males and females. Journal of Electromyography and Kinesiology, 102564. https://doi.org/10.1016/j.jelekin.2021.102564

Yoon S, Bailey CA, Côté JN. Sex-specific muscle activation and oxygenation kinetics during a repetitive forward pointing task. Applied Physiology, Nutrition, and Metabolism. https://doi.org/10.1139/apnm-2021-0664

Cycling workstation

Thu, 07 Oct 2021 00:00:00 +0000

Cycling workstation may be a novel solution to counteract the sedentarism in the office environment. The objectives of this project were to examine the effects of: 1) pedaling intensity (25% vs 40% heart rate reserve) and 2) biological sex (male vs female). The outcome measures included typing performance, neck/shoulder muscle activity, blood flow, sensitivity, and discomfort. In brief, we found that males and females respond differently to the different pedaling intensities, which should be considered when implementing mobile workstations in office setting. For more details, please refer to studies below:

Yoon, S., Lefrançois-Daignault, T., & Côté, J. N. (2019). Effects of cycling while typing on upper limb and performance characteristics. Applied ergonomics, 80, 161-167. https://doi.org/10.1016/j.apergo.2019.05.015

Yoon, S., Lefrançois-Daignault, T., & Côté, J. N. (2021). The Effect of Cycling While Typing on Patterns of Upper Body Muscle Activation. Human Factors, 00187208211022147. https://doi.org/10.1177/00187208211022147