Effects of isometric leg training on ambulatory blood pressure and morning blood pressure surge in young normotensive men and women.

Despite the reported association between diurnal variations in ambulatory blood pressure (BP) and elevated cardiovascular disease risk, little is known regarding the effects of isometric resistance training (IRT), a practical BP-lowering intervention, on ambulatory BP and morning BP surge (MBPS). Thus, we investigated whether (i) IRT causes reductions in ambulatory BP and MBPS, in young normotensives, and (ii) if there are any sex differences in these changes. Twenty normotensive individuals (mean 24-h SBP = 121 ± 7, DBP = 67 ± 6 mmHg) undertook 10-weeks of bilateral-leg IRT (4 × 2-min/2-min rest, at 20% maximum voluntary contraction (MVC) 3 days/week).

Getting the best GRIP on blood pressure control: Investigating a cost-effective isometric handgrip alternative.

Objectives: The World Health Organization emphasises the need for cost-effective alternative methods to lower blood pressure (BP). Endorsed nationally in HTN guidelines, isometric handgrip (IHG) training is an alternative method of BP control. The purpose of this study was to compare the BP, heart rate (HR) and rates of perceived exertion (RPE) responses between a bout of IHG training performed using the traditional computerized device and a more affordable, inflatable stress ball.

Physical literacy improves with the Run Jump Throw Wheel program among students in grades 4-6 in southwestern Ontario.

The purpose of this study was to determine whether the introduction of a fundamental movement skills (FMS) program to grade 4-6 physical education (PE) classes could improve students' physical literacy (PL) and influence the amount of effort exerted in PE class. Athletics Canada's grassroots Run Jump Throw Wheel (RJTW) Program was delivered for 10 weeks during PE classes (2 schools: four grade 4, four grade 5, two grade 6, one split grade 5-6 class, and one split grade 6-7 class, totalling 310 students). Participants completed the Canadian Assessment of Physical Literacy (CAPL) and wore heart rate monitors and pre- and postintervention.

Adiponectin-Consideration for its Role in Skeletal Muscle Health.

Adiponectin regulates metabolism through blood glucose control and fatty acid oxidation, partly mediated by downstream effects of adiponectin signaling in skeletal muscle. More recently, skeletal muscle has been identified as a source of adiponectin expression, fueling interest in the role of adiponectin as both a circulating adipokine and a locally expressed paracrine/autocrine factor. In addition to being metabolically responsive, skeletal muscle functional capacity, calcium handling, growth and maintenance, regenerative capacity, and susceptibility to chronic inflammation are all strongly influenced by adiponectin stimulation.

Acute Response to a 2-Minute Isometric Exercise Test Predicts the Blood Pressure-Lowering Efficacy of Isometric Resistance Training in Young Adults.

Background: This work aimed to explore whether different forms of a simple isometric exercise test could be used to predict the blood pressure (BP)-lowering efficacy of different types of isometric resistance training (IRT) in healthy young adults. In light of the emphasis on primary prevention of hypertension, identifying those with normal BP who will respond to IRT is important. Also, heightened BP reactivity increases hypertension risk, and as IRT reduces BP reactivity in patients with hypertension, it warrants further investigation in a healthy population.

Sex and life expectancy.

Background: A sexual dimorphism in human life expectancy has existed in almost every country for as long as records have been kept. Although human life expectancy has increased each year, females still live longer, on average, than males. Undoubtedly, the reasons for the sex gap in life expectancy are multifaceted, and it has been discussed from both sociological and biological perspectives.

The effects of recreational sport on VO₂peak, VO₂ kinetics and submaximal exercise performance in males and females.

The purpose of the present study was to examine changes in VO(2peak), VO(2) kinetics and steady-state exercise performance following 4 weeks of participation in recreational sport. Subjects (male n = 8, female n = 9) participated in recreational sport (basketball, floor hockey and soccer) four times per week for 4 weeks. Both before and after training, VO(2peak) was measured on a cycle ergometer, VO(2) kinetics was determined as the average of three transitions to 80 W, and heart rate (HR) and respiratory exchange ratio (RER) were measured during 60 min at a work rate corresponding to 50 % of pre-training VO(2peak).

Core temperature is a greater influence than endogenous 17β-estradiol on the exercise-induced accumulation of myocardial heat shock protein mRNA.

Female rats typically do not show significant increases in myocardial Hsp70 after exercise unless trained (exercise over days or weeks). 17β-Estradiol (E2) has been linked to this inhibition, but it varies considerably over the rodent estrus cycle. Consequently, we examined whether the inhibitory effects of endogenously produced E2 (measured immediately pre-exercise) were acute in exercised female Sprague-Dawley rats (60 min treadmill running at 30 m·min(-1)).

Heat shock proteins and exercise: a primer.

Heat shock proteins (HSPs) are, in general, prosurvival molecules within the cellular environment, and the overexpression of even just 1 family of HSPs can lead to protection against and improvements after a variety of stressors. Not surprisingly, a fertile area of study has grown out of efforts to exploit the innate biologic behaviour of HSPs. Exercise, because of the inherent physiologic stresses associated with it, is but 1 stimulus that can result in a robust increase in various HSPs in several tissues, not the least of which happen to be the heart and skeletal muscle.

Myocardial Hsp70 phosphorylation and PKC-mediated cardioprotection following exercise.

Both protein kinase C (PKC) activation and Hsp70 expression have been shown to be key components for exercise-mediated myocardial protection during ischemia-reperfusion injury. Given that Hsp70 has been shown to undergo inducible phosphorylation in striated muscle and liver, we hypothesized that PKC may regulate myocardial Hsp70 function and subsequent exercise-conferred cardioprotection through this phosphorylation. Hence, acute exercise of male Sprague-Dawley rats (30 m/min for 60 min at 2% grade) was employed to assess the role of PKC and its selected isoforms in phosphorylation of Hsp70 and protection of the myocardium during ischemia-reperfusion injury.

Response of the myocardium to exercise: sex-specific regulation of hsp70.

Sex is a potent modifier of the cardiovascular system because males and females differ in several aspects of the heart's biology and physiology. Epidemiologically, premenopausal women possess a distinct advantage over men in the occurrence of cardiovascular heart disease; however, this advantage shifts to men once a negative cardiac event has occurred. The reasons for these differences are not completely understood and are likely attributable to many factors.

Exercise-mediated regulation of Hsp70 expression following aerobic exercise training.

An issue central to understanding the biological benefits associated with regular exercise training is to elucidate the intracellular mechanisms governing exercise-conferred cardioprotection. Heat shock proteins (HSPs), most notably the inducible 70-kDa HSP family member Hsp70, are believed to participate in the protection of the myocardium during cardiovascular stress. Following acute exercise, activation of PKA mediates the suppression of an intermediary protein kinase, ERK1/2, which phosphorylates and suppresses the activation of the heat shock transcription factor 1 (HSF1).

Exercise training improves myocardial tolerance to ischemia in male but not in female rats.

Acute exercise increases myocardial tolerance to ischemia-reperfusion (I-R) injury in male but not in female rat hearts, possibly due to a decreased heat shock protein 70 (Hsp70) response in the female hearts. This study examined whether repetitive exercise training would increase Hsp70 and myocardial tolerance to I-R injury in female rat hearts. Adaptations in myocardial manganese superoxide dismutase (MnSOD) and endothelial nitric oxide synthase (eNOS) were also assessed.

Neuropeptide Y bioavailability is suppressed in the hindlimb of female Sprague-Dawley rats.

We recently reported that male, but not female, rats exhibit basal endogenous neuropeptide Y Y(1)-receptor modulation of hindlimb vasculature. The lack of baseline endo-genous Y(1)-receptor control in females was evident despite the expression of Y(1)-receptors and neuropeptide Y in hindlimb skeletal muscle tissue. The following study addressed the hypothesis that neuropeptide Y bioavailability is blunted in female rats under baseline conditions.

Gender-modulated endogenous baseline neuropeptide Y Y1-receptor activation in the hindlimb of Sprague-Dawley rats.

This study examined the effect of neuropeptide Y Y(1)-receptor blockade both alone, and in interaction with alpha(1)-adrenoceptor antagonism, on basal hindlimb vascular conductance in male and female Sprague-Dawley rats. Hindlimb vascular conductance was measured during infusion of BIBP3226 (Y(1)-receptor antagonist; 100 microg kg(-1)), prazosin (alpha(1)-receptor antagonist; 20 microg kg(-1)), and combined blockade. In males, vascular conductance increased 1.

Exercise-induced elevation of HSP70 is intensity dependent.

Exercise induces expression of the protective heat shock protein, HSP70, in striated muscle. To characterize the relationship between induction of this protein and exercise intensity in muscles exhibiting different recruitment patterns, male Sprague-Dawley rats were assigned to a sedentary control or one of seven exercise groups for which treadmill running speed varied between 15 and 33 m/min (n = 8/group). Twenty-four hours after a single 60-min exercise bout, hearts, red and white portions of the vastus (RV and WV, respectively) muscles, and soleus (Sol) muscles were harvested and analyzed for both relative and absolute HSP70 content.