Effect of Exercise Withdrawal on Stress Reactivity to Repeated Mental and Physical Challenge Tasks

Cessation of exercise has adverse consequences for health. There is a critical gap in the literature on the potential risks of dysregulated reactivity to stressors during periods of inactivity. This study examines experimentally controlled exercise withdrawal (EW) on reactivity to repeated exposure to mental and physical challenge tasks.

Regular exercisers (mean age ± SD: 31 ± 8 y; 55% females) were randomly assigned to either withdraw ( n = 20) or continue ( n = 20) their usual exercise for 2 weeks. Participants took part in 3 study visits during which they performed a mental challenge task (Stroop color-word test: Stroop) and a physical challenge task (cold pressor). Systolic blood pressure (SBP), diastolic blood pressure, and heart rate responses were measured at each visit. Change scores from baseline to peak levels were used to measure reactivity and a linear mixed-effect model was used to estimate the reactivity attenuation over time between the EW and control groups.

In response to the Stroop, the magnitude of attenuation over time was larger in the control group than in the EW group across all outcomes and time points. There were statistically significant attenuations in SBP (-8.46 mmHg; CI = -14.5, -2.5), diastolic blood pressure (-5.3 mmHg; CI = -9.5, -1.2), and heart rate (-9.1 bpm; CI = 15.36, -2.92) for the control group compared with only significant attenuations in SBP (-6.9 mmHg; CI = 12.9, -0.9) for the EW group in response to the Stroop. In response to the cold pressor, there were no statistically significant attenuations.

This investigation provides evidence that EW interferes with the attenuation of physiological responses to repeated mental challenge tasks.