continuous bout of equivalent duration, at reducing post-prandial lipaemia. There was little evidence on accumulation of bouts of <10 minutes.9 However, for health outcomes such as fitness, adiposity and psychological well-being, there was insufficient evidence to determine whether 'accumulation ' of short bouts was as effective as continuous activity. Frequency of Bouts or Sessions The optimal frequency of activity, in terms of the number of days per week that involve a session or bout of activity, has also not been extensively investigated. Few studies have demonstrated the benefits of activity carried out <3 times per week, but papers that have investigated the 'weekend warrior' concept (all activity on one day each week) indicate that there are benefits from weekly activity (for example playing golf).10,11 However, given that there are acute, as well as chronic metabolic benefits of physical activity, current consensus is that daily activity should be encouraged.12 Intensity For the purposes of reporting results from cohort studies, it is generally accepted that vigorous activity expends energy at the rate of moderate intensity activity; hence most researchers 'weight' time spent in vigorous activity by two when reporting activity time in minutes as the exposure variable. These studies rarely differentiate between the benefits of moderate and vigorous activity, and cannot distinguish their relative benefits. Is there greater benefit from vigorous activity? There is some evidence to indicate that for coronary heart disease and its risk factors, there may be greater risk reductions from vigorous activity. Nine epidemiological studies have now shown a lower risk of heart disease (or risk factor profile) for people who do vigorous activity, after adjusting for total volume of activity. However, only out of 20 clinical trials have confirmed that vigorous intensity activity confers greater improvement in maximal oxygen uptake than the same volume of moderate intensity activity.6 While vigorous exercise is important for improving many forms of athletic performance, it remains unclear whether doing vigorous activity adds to the substantial benefits that
Table 3.1. Summary of existing guidelines showing phrases used to convey recommendations about different forms of activity. Guidelines that Mention the Phrase: Moderate-intensity Vigorous activity Strength/ Balance/ Flexibility Sedentary behaviours Other Global 2010 At least 150 minutes of moderate-intensity aerobic physical activity throughout the week. For additional health benefits, adults should increase their aerobic physical activity to 300 minutes per week. . . . .or do at least 75 minutes of aerobic physical activity throughout the week . . . or engage in 150 minutes of aerobic physical activity per week. . . . . or an equivalent combination of moderate- and activity. . . or an equivalent combination of moderate- and activity. Muscle-strengthening activities should be done involving major muscle groups on 2 or more days a week. Aerobic activity should be performed in bouts of at least 10 minutes duration WHO 2008 30 minutes of physical activity on five or more days each week. If you can, enjoy some regular activity for extra health and fitness benefits. moderate-
1999 Put together at least 30 minutes of physical activity on most, preferably all, days. If you can, also some regular, vigorous activity for extra health and fitness. Think of movement as an opportunity, not an inconvenience. Be active day in an many ways as you can 2011 Accumulate at 150 minutes/week of moderate-intensity aerobic physical activity . . . Add muscle and bone strengthening activities using major muscles groups, at least 2 days per week. More physical activity provides greater health benefits. 2009 Improve aerobic fitness by being active several days a week, for total of at least 2 h 30 min of moderate activity . . . . . . . .or h 15 min of vigorous activity. In addition increase muscular strength and improve balance at least 2 times a week. 2009 All adults should undertake minutes of physical activity on 5 or more days of the week. (abbreviated to: At 30 minutes on days per week) Physical activity can consist of a combination of moderate- and periods. Activities to increase muscular strength and endurance should be added on 2 to 3 days per week. Shorter bouts of activity can be accumulated to reach the target. These bouts should be at least 10 minutes duration. All adults should avoid inactivity. Some activity is better than none, more is better than some, and adults who participate in any amount of physical activity gain some health benefits.
Footnote: The benefits of physical activity far outweigh the risk of remaining inactive or the risks of adverse outcomes. There is a slightly increased risk of injury or accident in adults who are unaccustomed to any physical activity at all, and in those doing high intensity, long duration activities. To reduce risk, those unaccustomed to activity are advised to start slowly (for example, by walking), and to adapt gradually towards recommended levels. Do not over-exert without sufficient training. Individual physical and mental capabilities should be considered when interpreting the guidelines PROPOSED NEW AUSTRALIAN PHYSICAL ACTIVITY GUIDELINES FOR ADULTS – DRAFT ONE Footnote: The benefits of physical activity far outweigh the risk of remaining inactive or the risks of adverse outcomes. There is a slightly increased risk of injury or accident in adults who are unaccustomed to any physical activity at all, and in those doing high intensity, long duration activities. To reduce risk, those unaccustomed to activity are advised to start slowly (for example, by walking), and to adapt gradually towards recommended levels. Do not over-exert without sufficient training. Individual physical and mental capabilities should be considered when interpreting the guidelines. RESULTS PART FIVE: CONSULTATION, FEEDBACK AND REVIEW INTRODUCTION As part of the development process, feedback on a draft of the proposed Evidence-Based Physical Activity and Sedentary Behaviour Recommendations for Adults was sought from a group of people identified as key stakeholders and/or with research/academic expertise in adult physical activity and health.
Your feedback is requested by Monday June 11, 2012 at 5pm. I apologise for the short notice that is required to meet the timelines for this work. Your involvement is greatly appreciated. With best wishes Wendy Brown, Adrian Bauman, Fiona Bull, Nicola Burton (consultants) Survey Link: Any questions about the survey can be directed to Helen Elizabeth Brown on email Wendy J Brown Professor of Physical Activity and Public Health School of Human Movement Studies, University of Queensland Blair Drive St Lucia QLD4072 Tel: +61 (0)7 3365 6446 Fax: +61 (0)7 3365 6887 ONLINE SURVEY USED IN THE CONSULTATION PROCESS Proposed Recommendations for Physical Activity and Sedentary Behaviour for Australian Adults (18-64 years) The following questions ask your opinion on the appropriateness, accuracy, content and wording of the proposed recommendations. There is also space for you to provide any additional comments. If you have any questions about this survey, please feel free to contact Helen Elizabeth Brown on There are 22 questions in this survey PREAMBLE The proposed preamble provides an overall statement on the benefits of physical activity. Regular physical activity reduces the risk of many adverse physical and psychosocial health outcomes. is clear evidence that doing some activity is better than doing none at all and increasing amounts of activity provide increasing benefit. [1] Is it appropriate to include a preamble? Please choose only one of the following: Yes