Reductions in resting blood pressure in young adults when isometric exercise is performed whilst walking

Aerobic and isometric training have been shown to reduce resting blood pressure, but simultaneous aerobic and isometric training have not been studied. The purpose of this study was to compare the changes in resting systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) after 6 weeks of either (i) simultaneous walking and isometric handgrip exercise (WHG), (ii) walking (WLK), (iii) isometric handgrip exercise (IHG), or control (CON). Forty-eight healthy sedentary participants (age 20.7 ± 1.7 yrs, mass 67.2 ± 10.2 kg, height 176.7 ± 1.2 cm, male , and female ) were randomly allocated, to one of four groups ( in each). Training was performed 4 × week−1 and involved either treadmill walking for 30 minutes (WLK), handgrip exercise 3 × 10 s at 20% MVC (IHG), or both performed simultaneously (WHG). Resting SBP, DBP, and MAP were recorded at rest, before and after the 6-week study period. Reductions in resting blood pressure were significantly greater in the simultaneous walking and handgrip group than any other group. These results show that simultaneous walking and handgrip training may have summative effects on reductions in resting blood pressure

Adaptation of arginine synthesis among uropathogenic branches of the Escherichia coli phylogeny reveals adjustment to the urinary tract habitat

Urinary tract infections (UTIs) are predominantly caused by uropathogeni

Reductions in ambulatory blood pressure in young normotensive men and women after isometric resistance training and its relationship with cardiovascular reactivity

Background: There has been very little published work exploring the comparative effects of isometric resistance training (IRT) on blood pressure (BP) in men and women. Most of the previously published work has involved men and used resting BP as the primary outcome variable. Early evidence suggests that IRT is particularly effective in older women and has a positive influence on ambulatory BP, a better predictor of disease risk. Objectives: With the WHO now placing global emphasis on the primary prevention of hypertension, the goals of this proof-of-concept study were to (i) examine whether sex differences exist in the ambulatory BP-lowering effects of IRT in young, normotensive men and women and (ii) determine whether these reductions can be predicted by simple laboratory stress tasks (a 2-min sustained isometric contraction and a math task involving subtracting a two-digit number from a series of numbers). Results: There were no differences in the IRT-induced reductions in 24-h (men: Δ4 mmHg, women: Δ4 mmHg), daytime (men: Δ3 mmHg, women: Δ4 mmHg), or night-time (men: Δ4 mmHg, women: Δ3 mmHg) ambulatory BP in men (n=13) and women (n=11) (P0.05). Conclusion: Our data suggest that lower ambulatory BP can be achieved, to a similar magnitude in young healthy women as well as men, with IRT; however, the BP-lowering effectiveness cannot be predicted by systolic BP reactivity. Taken together, this work heralds a potentially novel approach to the primary prevention of hypertension in both men and women and warrants further investigation in a larger clinical outcome trial

Validity of a pictorial perceived exertion scale for effort estimation and effort production during stepping exercise in adolescent children

This is the author's PDF version of an article published in European Physical Education Review ©2002. The definitive version is available at http://epe.sagepub.com.Recent developments in the study of paediatric effort perception have continued to emphasise the importance of child-specific rating scales. The purpose of this study was to examine the validity of an illustrated 1 – 10 perceived exertion scale; the Pictorial Children’s Effort Rating Table (PCERT). 4 class groups comprising 104 children; 27 boys and 29 girls, aged 12.1±0.3 years and 26 boys, 22 girls, aged 15.3±0.2 years were selected from two schools and participated in the initial development of the PCERT. Subsequently, 48 of these children, 12 boys and 12 girls from each age group were randomly selected to participate in the PCERT validation study. Exercise trials were divided into 2 phases and took place 7 to 10 days apart. During phase 1, children completed 5 x 3-minute incremental stepping exercise bouts interspersed with 2-minute recovery periods. Heart rate (HR) and ratings of exertion were recorded during the final 15 s of each exercise bout. In phase 2 the children were asked to regulate their exercising effort during 4 x 4-minute bouts of stepping so that it matched randomly prescribed PCERT levels (3, 5, 7 and 9). Analysis of data from Phase 1 yielded significant (P<0.01) relationships between perceived and objective (HR) effort measures for girls. In addition, the main effects of exercise intensity on perceived exertion and HR were significant (P<0.01); perceived exertion increased as exercise intensity increased and this was reflected in simultaneous significant rises in HR. During phase 2, HR and estimated power output (POapprox) produced at each of the four prescribed effort levels were significantly different (P<0.01). The children in this study were able to discriminate between 4 different exercise intensities and regulate their exercise intensity according to 4 prescribed levels of perceived exertion. In seeking to contribute towards children’s recommended physical activity levels and helping them understand how to self-regulate their activity, the application of the PCERT within the context of physical education is a desirable direction for future research

China and the crisis : global power, domestic caution and local initiative

Even though the global crisis had a quick and dramatic impact on Chinese exports, the Chinese government responded with a range of policy responses that have helped maintain high rates of growth. This success has helped propel China to the centre of global politics, accelerating what many perceive to be a power shift from the West to China. But these gains were achieved by reversing policy in previous years designed to make a fundamental shift in China‟s mode of development, and have highlighted the problems associated with making such a transition. At the moment that many are looking at the Chinese "model" as a potential alternative to the Washington Consensus, one of the consequences of the crisis is to further question the long term efficacy of this "model" in China itself

The relationship between EMG and either heart rate or blood pressure during a single-leg incremental isometric exercise test

Recently Wiles et al. (2008: Journal of Sports Sciences, 24, 155-162) introduced the linear relationship between double-leg EMG and either HR or BP during incremental isometric exercise as a novel method for regulating exercise intensity during training. However, many previous training studies (eg Wiley et al., 1992: Medicine and Science in Sports and Exercise, 24, 749-754) have employed single-leg protocols. The relationship between EMG and HR or BP during an incremental single-leg protocol has not been explored. Therefore, the purpose of this study was to determine whether these relationships were evident in a single-leg protocol. Following ethical approval fifteen healthy, normotensive (mean systolic blood pressure 123.8, s = 6.8 mmHg) and physically active men (age 24.8, s = 6.7 yrs; mass 78.8, s = 9.5 kg) performed a maximum voluntary contraction (MVC) using a seated isometric single-leg extension, from which peak torque (TORpeak) and EMG (EMGpeak) were determined. Subsequently, subjects performed two incremental isometric exercise tests at 10, 15, 20, 25 and 30 %EMGpeak, using dominant and non-dominant legs, during which HR and BP were measured continuously. The slope and elevation (intercept) of the linear regression lines obtained in each leg were compared with the use of analysis of covariance (ANCOVA). The within- and between-subjects variation of the mean HR, SBP, and %EMGpeak values was assessed using a repeated measures multivariate analysis of variance (MANOVA). The group mean data for each leg showed a linear relationship between %EMGpeak and HR (dominant leg r = 0.98; P0.05 and 0.98, P0.05 and 0.99, P< 0.001). The lack of a linear relationship in many individuals was probably due to the accumulation of local metabolites in the single-leg compared to the previously published double-leg isometric exercise. The inter-individual variation in the relationship between EMGpeak and HR or BP during the single-leg protocol, make it difficult to use the single-leg protocol, in the same way as the double-leg protocol, to prescribe isometric exercise intensity during training

Effects of isometric resistance training and detraining on ambulatory blood pressure and morning blood pressure surge in young normotensives

Isometric resistance training (IRT) has been shown to reduce resting and ambulatory blood pressure (BP), as well as BP variability and morning BP surge (MBPS). However, there are no data available regarding how long after cessation of IRT these effects are maintained. Therefore, the purpose of this study was to determine the effects of 8 weeks of detraining on resting BP, ambulatory BP and MBPS following 8 weeks of IRT in a population of young normotensive individuals and to further substantiate previously reported reductions in MBPS following IRT. Twenty-five apparently healthy participants with resting BP within the normal range (16 men, age=23±6 years; 9 women, age=22±4 years, resting BP: 123±5/69 ±7 mmHg) were randomly assigned to a training-detraining (TRA-DT, n=13) or control (CON, n=12) group. Resting BP, ambulatory BP and MBPS were measured prior to, after 8 weeks of bilateral leg IRT using an isokinetic dynamometer (4 x 2-minute contractions at 20% MVC with 2-minute rest periods, 3 days/week) and following an 8-week detraining period. There were significant reductions in 24-h ambulatory systolic BP (SBP) and calculated SBP average real variability (ARV) following IRT that were maintained after detraining (pre-to-post detraining, -6±4 mmHg, p=0.008, -2±1.5 mmHg, p=0.001). Similarly, the training-induced decreases in daytime SBP and daytime SBP ARV (pre-to-post detraining, -5±6 mmHg, p=0.001; -2±1.2 mmHg, p=0.001, respectively), MBPS (pre-to-post detraining, -6±9 mmHg, 34 p=0.046) and resting SBP (pre-to-post detraining, -4 ± 6 mmHg, P = 0.044) were preserved. There were no changes in night-time or night-time SBP ARV across all time points (pre-to�36 post detraining, -1±8 mmHg, p=1.00, -0.7±2.9 mmHg, p=1.00). These results confirm that IRT causes significant reductions in resting BP, ambulatory BP, ambulatory ARV and MBPS. Importantly, the changes remained significantly lower than baseline for 8 weeks after cessation of training, suggesting a sustained effect of IRT

Acute response to a 2-minute isometric exercise test predicts the blood pressure lowering efficacy of isometric resistance training in young adults

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. METHODS Forty-six young men and women (24 ± 5 years; 116 ± 10/ 68 ± 8 mm Hg) were recruited from 2 study sites: Windsor, Canada (n = 26; 13 women), and Northampton, United Kingdom (n = 20; 10 women). Resting BP and BP reactivity to an isometric exercise test were assessed prior to and following 10 weeks of thrice weekly IRT. Canadian participants trained on a handgrip dynamometer (isometric handgrip, IHG), while participants in the UK trained on an isometric leg extension dynamometer (ILE). RESULTS Men and women enrolled in both interventions demonstrated significant reductions in systolic BP (P < 0.001) and pulse pressure (P < 0.05). Additionally, test-induced systolic BP changes to IHG and ILE tests were associated with IHG and ILE training-induced reductions in systolic BP after 10 weeks of training, respectively (r = 0.58 and r = 0.77; for IHG and ILE; P < 0.05). CONCLUSIONS The acute BP response to an isometric exercise test appears to be a viable tool to identify individuals who may respond to traditional IRT prescription

Isometric exercise training for hypertension

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: We will aim to conduct a systematic review and meta-analysis quantifying the effects of IRT on systolic, diastolic, mean arterial and 24-hour ambulatory blood pressure. We will also quantify changes in heartrate and heartrate variability, and will attempt to determine which patient demographics and exercise program characteristics are associated with the largest blood pressure changes