Medicine and science in sports and exercise
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Med Sci Sports Exerc · Dec 2013
Temporal relationships between physical activity and sleep in older women.
The objective of this study is to examine the temporal and bidirectional relationships between accelerometer-derived physical activity estimates and actigraphy-assessed sleep characteristics among older women. ⋯ Few studies have used objective measures to examine the temporal relationships between physical activity and sleep. Notably, these findings suggest that nightly variations in sleep efficiency influence physical activity the following day. Thus, improving overall sleep quality in addition to reducing nightly fluctuations in sleep may be important for encouraging a physically active lifestyle in older women.
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Med Sci Sports Exerc · Dec 2013
Do older females store more heat than younger females during exercise in the heat?
Aging is associated with a reduction in the body's capacity to dissipate heat. To date, few studies have examined age-related changes in thermoregulatory function during short exercise periods in the heat in older females. ⋯ These findings suggest that older females have a lower capacity for whole-body EHL compared with younger females during short intermittent exercise in the heat performed at a fixed rate of metabolic heat production.
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Med Sci Sports Exerc · Aug 2013
Continued sedentariness, change in sitting time, and mortality in older adults.
Prolonged sitting time (ST) is associated with higher mortality. However, previous studies used only a single measure of ST at baseline, so they could not directly assess the effect of continued exposure to high ST, or of changes in ST, on mortality. We prospectively assessed the association of continued sedentariness and of changes in ST for 2 yr with subsequent long-term all-cause mortality. ⋯ Compared with older adults who were consistently sedentary during 2 yr, consistently nonsedentary individuals showed reduced all-cause mortality. Individuals who changed ST experienced an intermediate reduction in mortality.
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Med Sci Sports Exerc · Apr 2013
Head impact exposure sustained by football players on days of diagnosed concussion.
This study compares the frequency and severity of head impacts sustained by football players on days with and without diagnosed concussion and to identify the sensitivity and specificity of single-impact severity measures to diagnosed injury. ⋯ Players sustained more impacts and impacts of higher severity on days of diagnosed concussion than on days without diagnosed concussion. In addition, of historical measures of impact severity, those associated with peak linear acceleration are the best predictors of immediately diagnosed concussion.
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Med Sci Sports Exerc · Apr 2013
Timing of concussion diagnosis is related to head impact exposure prior to injury.
Concussions are commonly undiagnosed in an athletic environment because the postinjury signs and symptoms may be mild, masked by the subject, or unrecognized. This study compares measures of head impact frequency, location, and kinematic response before cases of immediate and delayed concussion diagnosis. ⋯ Concussions diagnosed immediately after an impact event are associated with the highest kinematic measures, whereas those characterized by delayed diagnosis are preceded by a higher number of impacts.