Affiliation:
1. Department of Physical Therapy University of Haifa Haifa Israel
2. Pediatric Exercise and Genomics Research Center School of Medicine University of California Irvine California USA
3. Department of Kinesiology Faculty of Applied Health Sciences Centre for Bone and Muscle Health Brock University St. Catharines Ontario Canada
Abstract
AbstractHeart Rate (HR) is widely used for erobic exercise intensity prescriptions and/or studies of exercise training. It is often assumed that exercising at a given HR results in similar physiological response, regardless of exercise modality. This study aimed to gauge cellular immune mobilization to submaximal exercise at a given target HR on a cycle ergometer (CE) and treadmill (TM). Thirteen healthy male adults (23.2 ± 3.5 y.o) completed 4 laboratory visits. Participants performed two graded exercise tests to exhaustion on CE and TM and two 30‐min constant exercise challenges at 70% HR reserve on CE or TM in random order. Rating of Perceived Exertion (RPE) was recorded every 5 min, and blood was drawn before and after exercise to measure leukocytes subpopulation levels, lactate, and IL‐6. HR was successfully “clamped” during the exercise in CE and TM (CE 156.7 ± 1.1; TM 159.3 ± 1.6 bpm). Cycling was perceived as more strenuous than running and was accompanied by a greater increase in lactate post‐exercise (p < 0.0001; 6.2 ± 0.3 vs. 2.9 ± 0.3 mmol/L). IL‐6 and leukocytes subpopulations were significantly elevated post‐exercise (p < 0.003) with no difference between exercise modalities (monocytes; CE 57.6% TM 61.2%, granulocytes; CE 41.37%, TM 50.1%, lymphocytes; CE 91.03%, TM 78.8%). The findings revealed that HR is not sufficient in and of itself to fully assess the metabolic stress associated with a given exercise modality. However, despite different metabolic and subjective stress, the IL‐6 and leukocyte counts relative changes were similar in the two modalities.