In a study examining the role of chronic mental stress in the recovery of muscle function and somatic sensations following resistance exercise, 31 undergraduate students in a weight-training class completed the Perceived Stress Scale and Undergraduate Stress Questionnaire.1 At a later visit, they performed an acute heavy-resistance leg press protocol that included a “ramping phase” and a “burnout phase.” During the “ramping phase,” subjects performed a variable number of sets of 10 repetitions of leg presses with increasing loads until a full set could not be completed. From this process, the subject’s 10 repetition maximal (10RM) capacity was identified. Following the final set of the “ramping phase,” 3 minutes of rest were provided before the beginning of the “burnout phase.” The latter consisted of 6 sets of leg presses performed to volitional exhaustion. For each subject, the load for the first set was the 10RM capacity determined in the “ramping phase.” The second set was 90% of this value. If the subject performed 10+ repetitions during the second set, the remaining sets 3 – 6 were kept at this weight. If subjects were unable to perform 10 repetitions, the load was reduced to 80% of 10RM for the remaining sets.
Maximal isometric force, perceived energy, fatigue and soreness were assessed in approximately 24 hour intervals for 4 days after exercise. Results demonstrated that higher levels of stress resulted in lower recovery curves and, conversely, lower levels of stress were associated with superior levels of recovery over a 4-day period following the exercise protocol. Those low in perceived stress returned to baseline several times faster than those reporting high stress levels. Stress was also significantly related to recovery trajectories of energy, fatigue and soreness.
Stults-Kolehmainen and colleagues suggest perturbations in the hypothalamic-pituitary-adrenal axis and immune system, physiological processes involved in repair of exercise-induced damage and psychological adjustments to stress, could play a role in recovery from strenuous resistance exercise. They conclude that stress, whether assessed as life event stress or perceived stress, can moderate recovery trajectories following strenuous resistance exercise and individuals may benefit from taking stress levels into account when considering length of recovery. They identify study limitations and suggestion additional lines of research to further examine the relationship between stress, exercise, physical recovery and psychological function. These include interventions such as Mindfulness-Based Stress Reduction to examine the potential role of stress reduction in enhancing recovery of muscle function following exercise.
1Stults-Kolehmainen MA, Bartholomew JB, Sinha R. Chronic psychological stress impairs recovery of muscular function and somatic sensations over a 96-hour period. J Strength Cond Res. 2014 Jul;28(7):2007-17.