Live high: train low increases muscle buffer capacity and submaximal cycling efficiency

This study investigated whether hypoxic exposure increased muscle buffer capacity (βm) and mechanical efficiency during exercise in male athletes. A control (CON, n=7) and a live high:train low group (LHTL, n=6) trained at near sea level (600 m), with the LHTL group sleeping for 23 nights in simulated moderate altitude (3000 m). Whole body oxygen consumption (V˙O₂) was measured under normoxia before, during and after 23 nights of sleeping in hypoxia, during cycle ergometry comprising 4×4-min submaximal stages, 2-min at 5.6 ± 0.4 W kg^–1, and 2-min 'all-out' to determine total work and V˙O_2peak. A vastus lateralis muscle biopsy was taken at rest and after a standardized 2-min 5.6 ± 0.4 W kg^–1 bout, before and after LHTL, and analysed for βm and metabolites. After LHTL, βm was increased (18%, P < 0.05). Although work was maintained, V˙O_2peak fell after LHTL (7%, P < 0.05). Submaximal V˙O₂ was reduced (4.4%, P < 0.05) and efficiency improved (0.8%, P < 0.05) after LHTL probably because of a shift in fuel utilization. This is the first study to show that hypoxic exposure, per se, increases muscle buffer capacity. Further, reduced V˙O₂ during normoxic exercise after LHTL suggests that improved exercise efficiency is a fundamental adaptation to LHTL.

How much physical activity is enough to prevent unhealthy weight gain? Outcome of the IASO 1st Stock Conference and consensus statement

A consensus meeting was held in Bangkok, 21–23 May 2002, where experts and young scientists in the field of physical activity, energy expenditure and bodyweight regulation discussed the different aspects of physical activity in relation to the emerging problem of obesity worldwide. The following consensus statement was accepted unanimously.
‘The current physical activity guideline for adults of 30 minutes of moderate
intensity activity daily, preferably all days of the week, is of importance for
limiting health risks for a number of chronic diseases including coronary heart disease and diabetes. However for preventing weight gain or regain this guideline is likely to be insufficient for many individuals in the current environment. There is compelling evidence that prevention of weight regain in formerly obese individuals requires 60–90 minutes of moderate intensity activity or lesser amounts of vigorous intensity activity. Although definitive data are lacking, it seems likely that moderate intensity activity of approximately 45 to 60 minutes per day, or 1.7 PAL (Physical Activity Level) is required to prevent the transition to overweight or obesity. For children, even more activity time is recommended. A good approach for many individuals to obtain the recommended level of physical activity is to reduce sedentary behaviour by incorporating more incidental and leisure-time activity into the daily routine. Political action is imperative
to effect physical and social environmental changes to enable and encourage physical activity. Settings in which these environmental changes can be implemented include the urban and transportation infrastructure, schools, and workplaces.’

Identifying the energy gap: magnitude and determinants of 5-year weight gain in midage women

Objective: The aims of this study were to estimate average yearly weight gain in midage women and to identify the determinants of weight gain and gaining weight at double the average rate.
Research Methods and Procedures: The study sample comprised 8071 participants (45 to 55 years old) in the Australian Longitudinal Study on Women's Health who completed mailed surveys in 1996, 1998, and 2001.
Results: On average, the women gained almost 0.5 kg per year [average 2.42 kg (95% confidence interval, 2.29 to 2.54) over 5 years]. In multivariate analyses, variables associated with energy balance (physical activity, sitting time, and energy intake), as well as quitting smoking, menopause/hysterectomy, and baseline BMI category were significantly associated with weight gain, but other behavioral and demographic characteristics were not. After adjustment for all of the other biological and behavioral variables, the odds of gaining weight at about twice the average rate (>5 kg over 5 years) were highest for women who quit smoking (odds ratio = 2.94; 95% confidence interval, 2.17, 3.96). There were also independent relationships between the odds of gaining >5 kg and lower levels of habitual physical activity, more time spent sitting, energy intake (but only in women with BMI > 25 at baseline), menopause transition, and hysterectomy.
Discussion: The average weight gain equates with an energy imbalance of only about 10 kcal or 40 kJ per day, which suggests that small sustained changes in the modifiable behavioral variables could prevent further weight gain.

Australian unity wellbeing index

Discussion concerning the Australian Unity wellbeing index.

Australian unity wellbeing index

We keep hearing it, but of course few of us believe it. Today another survey is out that says money doesn't always buy happiness! A new study has found the happiest Australians actually live in one of the poorest rural electorates.

Of course this means that the most disgruntled are in the heart of Sydney, the wealthiest city in the country.

Liz Eckerman is an associate professor in the Sociology Department at Deakin University. She's one of the authors of the Australian Unity Wellbeing Index, and spoke to Fran Kelly this morning.

Where pain = no gain : perspectives on sport, exercise and health, c. 1850-1920

A common perspective today is that sportspeople must train and compete to a level of exertion beyond the ‘pain threshold’ if they are to succeed; a view that has given rise to the popular expression ‘No Pain, No Gain’. Indeed, a common aphorism is that the health and quality of life of individuals and of the wider population is positively correlated with the frequency and vigour of physical exercise. In the period when modern sports were taking on their present characteristics (approximately 1850-1920), the prevailing opinions about the health and well-being effects of exercise were far more cautious, however. While the benefits of moderate exercise for physical and mental well-being went without question, too great an exertion was considered to be as risky as too little, causing ‘strain’ with the potential to inflict lasting and potentially fatal damage, including mental and physical complaints as diverse as neuralgia and ‘athletes’ heart’. The supposedly more strenuous sports, such as football, athletics and rowing, and the training required for them came under particular scrutiny in medical and popular discourses. This paper, an exercise in historical sociology, examines these discourses to demonstrate how advice about the risks on health of participating in sports and of too little or too much exercise more generally, was informed by prevailing physiological models and the interpretation of these within the medical profession and the wider population. The data sources include medical journals and texts, and sports training manuals from the period under investigation.