Masataka Umeda

Exercise, Hypoalgesia and Blood Pressure

A number of studies have indicated that exercise is associated with alterations in pain perception. In general, investigators have typically found a hypoalgesic response (i.e. diminished pain perception) to occur during and following exercise. It is currently unclear why exercise alters pain perception but some research indicates that there is an interaction between pain modulatory and cardiovascular systems. Elevated resting blood pressure (BP), such as hypertension, has been associated with reduced sensitivity to noxious stimulation. In addition, acute elevations in BP (pharmacologically) have also been associated with alterations in pain perception. Exercise elevates BP due to the physiological demands of the activity, but only a limited amount of research has been conducted examining the interaction between exercise, hypoalgesia and BP. Results from this research indicate that exercise significantly alters cardiovascular responses, and these alterations appear to be associated with alterations in pain perception. However, the interaction between exercise, pain perception and BP has been primarily examined indirectly. The mechanisms underlying the interaction between BP and pain perception are currently not entirely understood. It has been suggested that endogenous opioids may be involved in the interaction between BP and pain perception; however, results appear to be equivocal in the human research that has been conducted in this area. It has also been suggested that baroreceptor activation may play a role in the interaction between BP and pain perception.

Examination of the dose–response relationship between pain perception and blood pressure elevations induced by isometric exercise in men and women

The purpose of this study was to examine exercise-induced hypoalgesia (EIH) in men and women, and whether different magnitudes of BP elevations induced by isometric exercise systematically influenced pain perception. Twenty-five men and 25 women performed isometric exercise at 25% MVC for 1-min, 3-min, and 5-min while BP and pain perception were assessed. Results indicated that BP was significantly elevated (p<0.05) by isometric exercise in a dose-response manner. Pain thresholds were found to be elevated while pain ratings were lower (p<0.05) immediately following isometric exercise but not in a dose-response manner. It was concluded that isometric exercise produced EIH in men and women, and there was not a dose-response relationship between BP and EIH.

Influence of blood pressure elevations by isometric exercise on pain perception in women

Very little research has been conducted examining the relationship between blood pressure (BP), exercise, and hypoalgesia especially in women, even though research indicates that there is an interaction between pain modulatory and cardiovascular systems. The purpose of this study was to examine if pain perception was altered shortly after brief isometric contractions that caused an associated transient prior elevation in BP. Twenty-three healthy women completed two randomly-assigned sessions consisting of isometric exercise (25% MVC for 1-min and 3-min) and quiet rest. A pressure stimulus was applied to the right forefinger for a maximum of 2-min following isometric exercise and quiet rest. The participants pressed a button indicating pain threshold (PT), and rated the intensity (PR-I) and the unpleasantness (PR-U) using pain rating scales. BP was assessed every 15-s during exercise, quiet rest, and during exposure to the pressure stimulus. Results indicated that systolic and diastolic BP were significantly elevated during exercise, with higher BP following 3-min vs 1-min of exercise. Patterns of responses for PT, however, differed with a small increase in PT following 3-min vs 1-min of isometric exercise (d=0.38) while there was a small decrease in PT following 3-min vs 1-min of quiet rest (d=0.20). PR-I and PR-U were not found to change significantly following isometric exercise or quiet rest. It was concluded that both durations of isometric exercise significantly elevated BP, but these elevations in BP were not associated with a consistent alteration in pain perception in this sample of normotensive women.

Physical Activity, Screen-Based Sedentary Behavior, and Sleep Duration in Adolescents: Youth Risk Behavior Survey, 2011-2013.

This study examined the concurrent associations of physical activity and screen-based sedentary behavior with sleep duration among adolescents by using data from the national Youth Risk Behavior Survey 2011–2013. Using latent class analysis, we identified 4 latent subgroups of adolescents with various levels of physical activity and screen-based sedentary behavior. The subgroup with high levels of physical activity and low levels of sedentary behavior generally showed greater odds of having sufficient sleep (≥8 hours/night) than the other subgroups. Findings imply that concurrent achievement of a high level of physical activity and low level of screen-based sedentary behavior is necessary to promote sufficient sleep among adolescents.