Work

Changes in Cortisol Awakening Response During 10 Days of High-Intensity Cycling Exercise

Year: 2025

Type: article

Abstract: Previous studies suggest that the cortisol awakening response (CAR) shows a biphasic pattern—either an increase or a blunting—in response to exercise involving overload, potentially reflecting physiological adaptation. However, its response to continuous high-intensity exercise under controlled experimental conditions has not been sufficiently investigated. This pilot case series examined daily CAR changes during a 10-day high-intensity cycling protocol (20 min/day at 80% of maximal oxygen uptake [V˙O2max]) in two healthy male participants. The CAR increased during Days 1–4 and returned to baseline levels from Day 5 onward, showing similar trends in acute physiological responses. V˙O2max and/or maximum workload improved following the intervention. These findings support the methodological feasibility of longitudinal CAR monitoring during short-term high-intensity exercise under controlled experimental conditions and suggest that CAR may be a promising non-invasive biomarker for assessing short-term physiological adaptation.

Source: Life

DOI: 10.3390/life15121872

Authors: Yui Ogasawara, Takayuki Sugo, Hironobu Tsuchiya

Institutions: Osaka Metropolitan University, Osaka University of Health and Sport Sciences

Language: English

Topic: Stress Responses and Cortisol

Subfield: Behavioral Neuroscience

Field: Neuroscience

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,137