Determinants of endothelial function in a cohort of patients with peripheral artery disease.

OBJECTIVES: Endothelial dysfunction assessed by brachial artery flow-mediated dilatation (FMD) has been associated with cardiovascular events. There have been relatively few studies examining FMD or other measures of endothelial function in patients with peripheral artery disease (PAD). The aim of this study was to examine determinants of FMD in a homogenous cohort of patients with PAD. METHODS: We prospectively assessed patients presenting with life style-limiting intermittent claudication to establish the presence of cardiovascular risk factors, obesity and metabolic syndrome. Fasting serum was assayed for lipids, C-reactive protein, adiponectin, leptin, resistin and osteoprotegerin (OPG). FMD was measured by high-resolution ultrasound. RESULTS: Serum concentrations of OPG were elevated in patients with obesity and metabolic syndrome. FMD was impaired in patients with obesity and metabolic syndrome and negatively correlated with serum concentrations of OPG. By multiple regression analysis, metabolic syndrome was independently associated with impaired FMD after adjustment for age, smoking, ischaemic heart disease, cerebrovascular disease and severity of PAD. CONCLUSIONS: Our findings suggest that metabolic syndrome is an important determinant of endothelial function in patients with PAD, and OPG may be a useful biomarker of this effect.

Effects of static stretching on leg power during cycling.

AIM: This study investigated the effects of warm-up involving static stretching on leg power. It was expected that the inclusion of static stretching in the warm-up would decrease leg power. METHODS: Twenty-seven healthy volunteers (16 male, 11 female) participated in the study. A prospective, repeated measures design was implemented where volunteers underwent 2 testing sessions at least 24 hours apart. One testing session involved a control warm-up (5 min submaximal cycling) followed by 4 10-s leg power tests at 5, 20, 40 and 60 min postwarm-up. For the other testing session, the subjects performed 5 min of submaximal cycling followed by 15 min of lower body static stretching and then the four leg power tests. Relative peak power, time to peak power and relative total work were measured for each leg power test. RESULTS: Peak power and total work were significantly greater after the static stretching warm-up compared to the control warm-up on all power tests. Peak power was achieved more quickly for the static stretching warm-up compared to the control warm-up on the 5 min test only. CONCLUSIONS: A warm up that includes static stretching has beneficial effects on anaerobic power events in comparison to submaximal cycling alone.

Exercise, mobility and aging.

The elderly population is growing both in size and in proportion of the total population. The costs to the community of the elderly being in poor health are also growing proportionately. The beneficial effects of exercise on various physiological and psychological parameters in the elderly have been well established. The effects of exercise on the mobility and independence of the elderly are also of primary concern, their maintenance being an important exercise goal. Impaired balance and gait are the 2 most significant risk factors for limited mobility and falls in the elderly. It is important to understand the effects of aging and exercise on these risk factors.

Dynamics of exercise induced affect.

This study investigated: (a) whether moderate intensity aerobic exercise exerted a significant affective influence during, and postexercise, (b) the nature of the affective response to exercise in relation to positive and negative affects, and affects associated with physiological distress, and (c) whether exercise induced affect was significantly influenced by exercise behaviour. Habitual exercisers (n = 15) and sedentary participants (n = 13) undertook three randomly allocated interventions; (a) exercise (EX; i.e., 20 min of cycling at 60% estimated VO2max), (b) normal workstation duties for 60 min (WRK), and (c) a 60 min sedentary lunch break (SED). Affect was measured pre, post, and 90 min postintervention, as well as every 5 min during exercise, using the Subjective Exercise Experiences Scale (SEES; McAuley & Courneya, 1994). Exercise behaviour had no significant affect on affective responses to exercise in this study (p > .05). Significant (p < .05) postintervention increases in positive affect were found for EX compared to WRK and SED indicating that exercise did produce a positive affective influence. Despite enduring postexercise (i.e., 90 min) improvements in both positive and negative affects, and affects related to fatigue, the affective response during exercise was characterised by significant (p < .05) decreases in levels of positive affect and increased levels of affects related to fatigue.

Discriminant analysis of biomechanical differences between novice, good and elite rowers.

Oar force and oar angle data resulting from a 6-min maximal rowing ergometer test undertaken by novice (n = 9), good (n = 23) and national (n = 9) level male rowers, were used to identify biomechanical performance variables which accurately discriminated between rowers of differing ability levels. The variables included two work capacity measures, mean propulsive power output per kilogram of body mass (W kg-1) and propulsive work consistency (%), and two skill variables, stroke-to-stroke consistency (%) and stroke smoothness (%). Discriminant function analysis indicated the presence of two functions, both of which clearly indicated the importance of mean propulsive power output per kilogram of body mass as a discriminating variable. Function 2 gave greater weight to stroke-to-stroke consistency and stroke smoothness than function 1; however, function 1 was the most powerful discriminator. Classification procedures were used to predict the ability level to which a rower most likely belonged and involved defining the 'distance' between each rower and each ability level centroid, with the rower being classified into the 'nearest' ability level. These procedures indicated that 100% of the elite, 73.9% of the good, 88.9% of the novice and 82.9% of all rowers were correctly classified into their respective skill levels. Stepwise discriminant analysis included the variables in the following order: mean propulsive power output per kilogram of body mass, stroke-to-stroke consistency, stroke smoothness and propulsive work consistency (P < 0.001). The results of this study indicate that biomechanical performance variables related to rowing capacity and skill may be identified and used to discriminate accurately between rowers of differing skill levels, and that, of these variables, propulsive work consistency is the least effective discriminator.