Effects of isometric handgrip training dose on resting blood pressure and resistance vessel endothelial function in normotensive women.

Isometric handgrip (IHG) training lowers resting blood pressure (BP) in both hypertensives and normotensives, yet the effect of training dose on the magnitude of reduction and the mechanisms associated with the hypotensive response are elusive. We investigated, in normotensive women, the effects of two different doses of IHG training on resting BP, and explored improved resistance vessel endothelial function and heart rate variability (HRV) as potential mechanisms of BP reduction. Resting BP, HRV, and resistance vessel endothelial function (venous strain-gauge plethysmography with reactive hyperemia) were assessed in 32 women before and after 4 and 8 weeks of 3×/week (n = 12) or 5×/week (n = 11) IHG training (four, 2-min unilateral contractions at 30 % maximal voluntary contraction), or 0×/week control (n = 9). IHG training decreased systolic BP in the 3×/week (94 ± 6 to 91 ± 6 to 88 ± 5 mmHg, pre- to mid- to post-training; P < 0.01) and 5×/week (97 ± 11 to 90 ± 9 to 91 ± 9 mmHg, P < 0.01) groups, concomitant with increased forearm reactive hyperemic blood flow (26 ± 7 to 30 ± 8 to 36 ± 9 mL/min/100 mL tissue, P < 0.01; and 26 ± 7 to 29 ± 7 to 38 ± 13 mL/min/100 mL tissue, P < 0.01, respectively), yet both remained unchanged in the control group. No changes were observed in diastolic BP, mean arterial BP, or any indices of HRV in any group (all P > 0.05). In conclusion, IHG training lowers resting systolic BP and improves resistance vessel endothelial function independent of training dose in normotensive women.

Barriers are not the limiting factor to participation in physical activity in canadian seniors.

The identification of barriers to physical activity and exercise has been used for many decades to explain exercise behavior in older adults. Typically health concerns are the number one barrier to participation. Data from CCHS-HA dataset (N = 20, 875) were used to generate a sample of Canadians, 60+ years, who did not identify a health condition limitation, illness, or injury as a barrier to participation in physical activity (n = 4,900) making this dataset unique in terms of the study of barriers to participation. While the vast majority of older adults participated in physical activity, 9.4% did not. The relationships between nonparticipation, barriers, self-reported health status, and chronic health conditions were determined using binary logistic regression. The main findings suggest that traditional barriers and self-reported health status are not responsible for nonparticipation. Nonparticipation was best predicted by chronic health conditions suggesting a disconnect between self-reported health status and underlying health conditions. The data are clear in suggesting that barriers are not the limiting factor and physical activity programming must be focused on meeting the health needs of our aging population.

Increasing the distance of an external focus of attention enhances learning.

Previous studies (e.g., Wulf, Höss, & Prinz, 1998) have shown that motor learning can be enhanced by directing performers' attention to the effects of their movements ("external focus"), rather than to the body movements producing the effect ("internal focus"). The purpose of the present study was to test the hypothesis that increasing the distance between the body and the action effects might further enhance the learning advantages associated with an external focus of attention. The distance of the external effect was manipulated by instructing three groups of participants learning to balance on a stabilometer to focus on markers attached to the platform located at different distances from their feet. Specifically, two groups were to focus on distant markers on the outside ("far-outside") or inside ("far-inside") of the platform, respectively, whereas another group was instructed to focus on markers close to their feet ("near"). In a retention test administered after two days of practice, all three external-focus groups showed generally more effective balance learning than an internal-focus control group. In addition, the far-outside and far-inside groups demonstrated similar performances, and both were more effective than the near group. Furthermore, the far-outside and far-inside groups showed higher-frequency movement adjustments than the near group. These results suggest that focusing on more distant effects results in enhanced learning by promoting the utilization of more natural control mechanisms. The findings are in line with a "constrained action" hypothesis that accounts for the relatively poorer learning associated with an attentional focus directed towards effects in close proximity to the body, or towards the body itself.

Attentional focus on supra-postural tasks affects postural control.

We examined whether the attentional focus adopted on a supra-postural task has an influence on postural control. Similar to Riley, Stoffregen, Grocki, and Turvey (Human Movement Science 18 (1999) 795), participants were instructed to stand still while lightly touching a loosely hanging sheet with their fingertips. However, instructions varied slightly under two conditions: Participants were either asked to minimize movements of the finger (internal focus) or to minimize movements of the sheet (external focus). In contrast to Riley et al.'s findings, both touch conditions resulted in increased postural sway, compared to a baseline condition (no touch). However, in line with previous findings (e.g., Wulf, McNevin, & Shea, Quarterly Journal of Experimental Psychology 54A (2001) 1143), frequency of responding (fast Fourier transformation) was greater under the external focus condition, compared to both internal focus and baseline conditions. The findings indicate improved static balance responses under external focus conditions and compromised static balance response under internal focus conditions.