INTERVAL EXERCISE STIMULATES A GREATER TRANSCRIPTIONAL RESPONSE THAN CONTINUOUS EXERCISE WITHIN AGING HUMAN SKELETAL MUSCLE

Authors

RE Perez
AC D'Lugos
JM Dickinson, FACSM

Abstract

R.E. Perez¹, A.C. D’Lugos², J.M. Dickinson, FACSM¹

¹Central Washington University, Ellensburg, WA, USA; ²California State University – Chico, Chico, CA, USA

Exercise is one of the most effective strategies for preserving skeletal muscle health and function with advancing age. However, the molecular mechanisms producing these benefits are less established, and thus to what extent various modes of exercise can be utilized to target impairments in aging muscle is not fully understood. PURPOSE: To identify the transcriptional response of older adult skeletal muscle to acute high-intensity interval (HIIE) and moderate-intensity continuous (MIC) cycling exercise. METHODS: Eight older adults (5M, 3F; 67±2yr; BMI: 26±2kg･m^-2) completed two exercise trials separated by ~1 week. One trial consisted of HIIE cycling (ten, 1-min intervals, 85-95% heart rate max, 1-min rest between intervals) and the other consisted of MIC cycling (30-min, 65-70% VO_2peak). Muscle biopsies (vastus lateralis) were obtained before and 4h post exercise. Whole transcriptome next-generation sequencing was performed on cDNA synthesized from skeletal muscle RNA. Sequencing data were analyzed using HTSeq and differential gene expression from pre-exercise was identified using an adjusted P value of ≤0.10. RESULTS: A total of 55 genes were responsive to both HIIE and MIC. Regarding the unique response to each exercise mode, 264 genes were only responsive to HIIE whereas 149 genes were only responsive to MIC. Interestingly, TNFRSF12A, a gene that is associated with muscle growth, was upregulated by HIIE but not by MIC (P<0.05; normalized counts above pre exercise [mean±SE]: 292±131 vs. 56±29). CONCLUSION: These data highlight that despite less total work, acute HIIE stimulates a greater transcriptional response within the skeletal muscle of older adults as compared to MIC, at least in the immediate hours following acute exercise. While future work is necessary to determine how these transcriptional responses correlate with specific skeletal muscle adaptations, HIIE may provide a better stimulus to promote muscle growth/delay muscle loss in older adults.

Recommended Citation

Perez, RE; D'Lugos, AC; and Dickinson, FACSM, JM (2024) "INTERVAL EXERCISE STIMULATES A GREATER TRANSCRIPTIONAL RESPONSE THAN CONTINUOUS EXERCISE WITHIN AGING HUMAN SKELETAL MUSCLE," International Journal of Exercise Science: Conference Proceedings: Vol. 8: Iss. 12, Article 32.
Available at: https://digitalcommons.wku.edu/ijesab/vol8/iss12/32