Muscle pain and blood pressure responses during isometric handgrip exercise in healthy African American and non-Hispanic White adults.

It has been shown that African Americans (AAs) are more sensitive to experimental pain stimuli compared to non-Hispanic Whites (NHWs). A single bout of exercise results in naturally-occurring muscle pain and elevation in blood pressure (BP); however, it is currently unclear whether AAs and NHWs differ in muscle pain and BP responses during exercise. Therefore, we examined the differences in muscle pain and blood pressure (BP) during isometric handgrip exercise in African Americans (AAs) and non-Hispanic Whites (NHWs). Fourteen AAs and 14 NHWs completed isometric exercise consisting of squeezing a hand dynamometer at 25% of maximal strength for 3 min. During exercise, muscle pain ratings (MPRs) were assessed every 30s, whereas systolic and diastolic BP (SBP and DBP) were recorded every minute. During exercise, AAs generally reported greater MPR than NHWs (p<0.001), and MPR increased more rapidly during exercise in AAs than NHWs (p<0.05). In contrast, SBP and DBP continued to increase similarly during exercise in both AAs and NHWs (p>0.05). The results suggest that AAs generally experienced a greater intensity of muscle pain than NHWs during isometric handgrip exercise, but both groups exhibited similar elevations in BP during exercise.