The dosing of aerobic exercise therapy on experimentally-induced pain in healthy female participants

Abstract

Knowledge of efficacious dosing respective to exercise type and pain condition is extremely limited in the literature. This study aimed to determine the impact of dose of moderate intensity treadmill walking on experimentally-induced pain in healthy human participants. Forty females were divided into 4 groups: control (no exercise), low dose exercise (3×/wk), moderate dose exercise (5×/wk) or high dose exercise (10×/wk). Over a 7-day period, subjects performed treadmill walking during assigned exercise days. Both qualitative and quantitative measures of pain were measured at baseline, during the trial, and 24 hrs post-final intervention session via sensitivity thresholds to painful thermal and painful pressure stimulation. Significant effects of treatment were found post-intervention for constant pressure pain intensity (p = 0.0016) and pain unpleasantness ratings (p = 0.0014). Post-hoc tests revealed significant differences between control and moderate and control and high dose groups for constant pressure pain intensity (p = 0.0015), (p = 0.0094), respectively and constant pressure pain unpleasantness (p = 0.0040), (p = 0.0040), respectively. Moderate and high dose groups had the greatest reductions in ratings of pain, suggesting that our lowest dose of exercise was not sufficient to reduce pain and that the moderate dose of exercise may be a sufficient starting dose for exercise-based adjuvant pain therapy.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1

The effects of exercise intervention on qualitative and quantitative measures of pressure pain. (A) Percent baseline pressure pain intesnity (VAS) in the forearm was significantly different from the control group for moderate and high dose groups. (B) Percent baseline pressure pain unpleasantness (VAS) in the forearm was significantly different from the control group for the moderate and high dose groups. (C) There were no significant different between groups for percent baseline pressure pain threshold as meausred in the forearm. Tukey post-hoc significant differences between groups at **p < 0.01. Data shown as mean +/− SEM. (D) Model representation of average pressure pain thresholds (PPT) compared to their subsequent pain intensity rating (VAS) at baseline (Base) and post-intervention (Post) for the moderate and high groups.

Figure 2

Acute effects of exercise on HR. No significant effect of treatment was found for exercise groups on percent change in HR. Data shown as mean +/− SEM.

Figure 3

Acute effects of exercise on QST for the forearm and calf. Results of univariate tests of between-subjects effects. (A) Acute effect of intervention on pressure pain threshold for the forearm, (p = 0.006) for DAY at 5 min time point. (B) Pressure pain intensity for the forearm, (p = 0.007) for Treat at 30 min time point. (C) Pressure pain unpleasantness for the forearm, (p = 0.005) for Treat at 5 min time point and (p < 0.001) for Treat at 30 min time point. (D) Constant heat intensity for the calf, (p = 0.004) for Treat at 30 min time point. (E) Pressure pain threshold for the calf, (p = 0.006) for Treat at 5 min time point and (p = 0.007) for DAY at 30 min time point. Data shown as mean +/− SEM.