Australian fitness professionals' level of interest in engaging with high health-risk population subgroups: findings from a national survey.

OBJECTIVES: Fitness industry professionals (personal trainers, group instructors) may have a role in health promotion, particularly when working with subgroups with known health risks (e.g. older adults, obese). The aim of this study is to examine fitness professionals' level of interest in engaging with high-risk populations. STUDY DESIGN: Cross-sectional evaluation of a national survey. METHODS: In 2014, 9100 Australian registered exercise professionals were invited to complete an online survey. Respondents reported their level of interest in engaging with nine health-risk population subgroups. A multivariable logistic regression analysis assessed the odds of being classified as having a 'low level' of interest in training high health-risk subgroups, adjusting for demographic and fitness industry-related factors. RESULTS: Of 1185 respondents (aged 17-72 years), 31.1% reported having a 'high level' of interest in training high health-risk subgroups. The highest level of interest was among 'obese clients' and 'adults (18-64 years) with chronic health conditions'. In the adjusted analysis, males (odds ratio [OR], 1.55, 95% confidence interval [CI]: 1.06-2.25) and those in urban settings (OR, 2.26, 95% CI: 1.54-3.37) were more likely to have a 'low level' of interest. CONCLUSIONS: Fitness professionals have a modest level of interest in training high health-risk subgroups. In addition to the development of strategies to increase interest, research should examine whether fitness professionals are able to safely prescribe exercise to high health-risk subgroups.

Neural mechanisms in human obesity-related hypertension.

OBJECTIVE: Two hypotheses concerning mechanisms of weight gain and of blood pressure elevation in obesity were tested. The first hypothesis is that in human obesity sympathetic nervous system underactivity is present, as a metabolic basis for the obesity. The second hypothesis, attributable to Landsberg, is that sympathetic nervous activation occurs with chronic overeating, elevating blood pressure. These are not mutually exclusive hypotheses, since obesity is a heterogeneous disorder. DESIGN AND METHODS: Whole body and regional sympathetic nervous system activity, in the kidneys and heart, was measured at rest using noradrenaline isotope dilution methodology in a total of 86 research voluteers in four different subject groups, in lean and in obese people who either did, or did not, have high blood pressure. RESULTS: In the lean hypertensive patients, noradrenaline spillover for the whole body, and from the heart and kidneys was substantially higher than in the healthy lean volunteers. In normotensive obesity, the whole body noradrenaline spillover rate was normal, mean renal noradrenaline spillover was elevated (twice normal), and cardiac noradrenaline spillover reduced by approximately 50%. In obesity-related hypertension, there was elevation of renal noradrenaline spillover, comparable to that present in normotensive obese individuals but not accompanied by suppression of cardiac noradrenaline spillover, which was more than double that of normotensive obese individuals (P<0.05), and 25% higher than in healthy volunteers. There was a parallel elevation of heart rate in hypertensive obese individuals. CONCLUSIONS: The sympathetic underactivity hypothesis of obesity causation now looks untenable, as based on measures of noradrenaline spillover, sympathetic nervous system activity was normal for the whole body and increased for the kidneys; the low sympathetic activity in the heart would have only a trifling impact on total energy balance. The increase in renal sympathetic activity in obesity may possibly be a necessary cause for the development of hypertension in obese individuals, although clearly not a sufficient cause, being present in both normotensive and hypertensive obese individuals. The discriminating feature of obesity-related hypertension was an absence of the suppression of the cardiac sympathetic outflow seen in normotensive obese individuals. Sympathetic nervous changes in obesity-related hypertension conformed rather closely to those expected from the Landsberg hypothesis.