Does exercise intensity affect wellness scores in a dose-like fashion?

Wellness questionnaires are common in monitoring systems, yet the sensitivity to variations in acute training intensity is unclear. This study examined the controlled dosage effects of differing exercise intensities on wellness variables and subsequent associations with neuromuscular performance. Participants (n = 10) completed low-, moderate- and high-intensity conditions of a 90 min simulated football match shuttle running protocol scaled relative to beep test scores. The protocols were completed in a randomised and counterbalanced fashion matched for time of day. Wellness (sleep quality, readiness to train, soreness, fatigue, stress, mood, motivation) and neuromuscular performance (maximal voluntary contraction, countermovement jump, 6 s cycle-ergometer sprint) were assessed pre-, post- and 24 h post-exercise. Heart rate (HR) and rating of perceived exertion (RPE) were recorded during, and session RPE (sRPE) after exercise. Generalised linear mixed models demonstrated main effects between conditions with increased HR, RPE and sRPE (P < 0.03; d > 0.8) responses from the low-high condition. Total and z-score wellness showed no significant differences between trials at any time-point (P > 0.05; d = 0.03-0.91). Fatigue was lower 24 h post-exercise for the low, compared to moderate and high conditions (P = 0.006-0.047; d = 1.20-1.77). Ratings of fatigue and soreness increased from pre- to 24 h post-trial (P < 0.003; d = 0.96-2.48), while total wellness and readiness to train decreased over time (P < 0.04; d = 0.91-1.86). Wellness showed limited capacity to differentiate training intensities. Practitioners should be aware while wellness may be highly practical, it may be limited to solely determine athlete accommodation of load considering the strength of association observed with the applied load.