Stress-induced complaints included measures of negative mood, distress, somatic complaints, general health complaints, illness severity, and health care use. The impact of physical activity was determined as the proportion of significant interaction effects between stress, activity and complaint in each study, with categories of full support (>2/3 of all interactions significant), partial support (>1/3 of all interactions significant) and no support (<1/3 of all interactions significant). Of the 12 cross sectional studies, 4 were classified as providing full support, 3 as partial support, and 5 as no support. Of the three longitudinal studies, 2 were classified as providing full support and one as providing partial support. No information was provided on dose-response relationships. PHYSICAL ACTIVITY AND PSYCHOSOCIAL WELLBEING As previously stated, The US Department of Health and Human Services report combined evidence for psychological wellbeing and distress, with the conclusion was that the available evidence from prospective cohort studies indicated a small to moderate association that favours people who are physically active. These results have been reported in the previous section on physical activity and stress. The report also identified enhanced self-esteem and reduced chronic fatigue as significant aspects of mental health that could benefit from physical activity. Results were cited from a meta-analysis of approximately 50, mostly small, RCTs of exercise and self-esteem: this demonstrated an average increase in self-esteem of 0.25SD. There was little evidence on the relationship between physical activity and chronic fatigue syndrome. Five RCTs were described as showing a small positive effect, and population-based observational studies suggested a protective effect against feelings of fatigue or low energy (OR=0.61, 95%CI 0.52-0.72). We identified five quantitative reviews that examined the results of studies of physical activity and psychological wellbeing. Two of these (one systematic review, one focussed on quality of life, one meta-analysis focussed on positive affect, and one review focussed on feelings of energy and fatigue. Bize et al., conducted a systematic review of studies (published 1996-2006) on the association between physical activity and health related quality of life (HRQoL). Of the 14 studies identified, 12 included a psychological subcomponent of HRQoL (vs for
201013 Occupational SB 201114 Leisure time SB 201115 TV and SB 201016 Depression Evidence is: No. of studies 43 19 48 11 Study design x-s c-c p p p x-s p BMI and weight gain x-s 5/10 c-c 0 p 1/3 p 4/10 p 13/18 Mixed Diabetes x-s 1/1 c-c - p 2/3 p 2/2 p 4/4 Moderate biomarkers p 3/7 Mixed disease c-c ½ p 3/6 p 2/4 p 1/1 Mixed Cancers p 4/4 p 1/13 p 4/5 Mixed Depression x-s 6/10 p 2/2 Limited All-cause mortality p 4/6 p 2/3 p 6/6 Strong or convincing Study design: x-s=cross sectional; c-c=case control; p=prospective. The conclusions from the three main reviews were that the majority of the prospective studies found that occupational/leisure time sitting was associated with higher risk of mortality. There was moderate or mixed evidence of relationships between sitting time and diabetes and a range of weight related health outcomes, including weight gain and obesity, and insufficient evidence to support any relationship for cancer or CVD (including CVD biomarkers).13-15 Although the level and strength of the evidence appears to be increasing, heterogeneity of study designs, measures and findings made it difficult to draw definitive conclusions. The review that focussed only on depression
activity, 500 – 1000 MET.min/week equates with 75 – 150 minutes of vigorous activity per week. The minimal volume of 500 MET.min/week can be achieved by moderate-intensity activity alone, by vigorous activity alone, or through combinations of moderate and vigorous intensity activity, as indicated by the examples in Table 2.1. Table 2.1: Examples of activity patterns that will accrue the minimal recommended amount of 150 minutes/week of moderate intensity, or 75 minutes/week of vigorous activity, or a combination. (These patterns are examples; many other combinations of activities will provide this amount of activity). Frequency /week Duration (mins) Total minutes Intensity (METs) Volume or dose (MET.min) Example Moderate intensity only 5 30 150 3.33 500 Brisk walking (5 km/hour) Moderate intensity only 10 15 150 3.33 500 Walk to work, 15 minutes, twice a day Vigorous intensity only 25 75 6.66 500 'Aerobics' (Vigorous exercise class) Vigorous intensity only 4 19 76 6.66 506 Jogging Combination of moderate and vigorous using generic MET values 1 + 2 30 + 30 30 + 60 3.33 + 6.66 100 + 400 Brisk walking + Basketball
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, 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 enjoy some regular, vigorous activity for extra health and fitness. Think of movement as an opportunity, not an inconvenience. Be active every day in an many ways as you can 2011 Accumulate at least 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. 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.
(abbreviated to: At least 30 minutes on days per week) The 2011 For adults (18 to 54 years) the norm is: at least half an hour of moderately intensive physical activity (4 to 6.5 MET; walking (5km/h) or cycling (16 km/h) briskly), on at least five days a week (summer and winter). New 2005 30 minutes moderate intensity physical activity on most, preferably all, days. If you can, also enjoy some regular, vigorous activity for extra health and fitness. 2004 Adults are recommended to take at least 30 minutes of moderate or vigorous physical activity every day. This activity be made up of several sessions during the day, each lasting at least 10 minutes.
2006 Engage in physical activity every day for at least half an hour at moderate level intensity. Endurance training 3 x per week 20-60 minutes. Strength and flexibility exercises 2 x per week. UK 2011 Over a week, activity should add up to at least 150 minutes (2½ hours) of moderate intensity activity in bouts of 10 minutes or more – one way to approach this is to do 30 minutes on at least days a week. Alternatively, comparable benefits can be achieved through 75 minutes of vigorous intensity activity spread across the week . . . or of moderate and vigorous intensity activity. Adults should also undertake physical activity to improve muscle strength on at least two days a week. All adults should minimise the amount of time spent being sedentary (sitting) for extended periods. Adults should aim to be active daily. USA 2008 For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) a week of moderate intensity. . For additional and more extensive health benefits, adults should increase their aerobic physical activity to 300 minutes (5 . . .or 75 minutes (1 hour and 15 minutes) a week of vigorous aerobic activity. . . or 150 minutes a week of . . or an equivalent combination of moderate- and activity. . . or an equivalent Adults should also do muscle-strengthening activities that are moderate or high intensity and involve all muscle groups on 2 or more days a week, as these activities provide additional health benefits. All adults should avoid inactivity. Some physical activity is better than none, and adults who participate in any amount of physical activity gain some health benefits. Aerobic activity should be performed in episodes of at least 10 minutes, and preferably it should be spread throughout the week.
Materials The proposed Evidence-Based Physical Activity and Sedentary Behaviour Recommendations for Adults were provided (in confidence). Participants received only the preamble, summary scientific statements and proposed guidelines (see Table 5.1). This document was developed after feedback from The Department of Health and Ageing on an initial draft. Table 5.1. Proposed new physical activity guidelines (draft one) circulated for comment. PROPOSED AUSTRALIAN RECOMMENDATIONS FOR PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR FOR ADULTS (18-64 YEARS) Preamble: 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. Summary of the Scientific Evidence Proposed Australian Guidelines The relationship between physical activity and health benefit is curvilinear. This means that the benefits increase with increasing amounts of physical activity, with 'diminishing returns' at the highest levels of activity. ONE Doing any regular physical activity is better than doing none. If you currently do no physical activity, start by doing some activity, and then build up to the recommended amount. is no clear evidence on the optimal frequency of physical activity, but there is strong support for recommending that adults should accumulate their physical activity across the week. Being active on most, if not all, days each week, is likely to provide increased metabolic benefits. TWO Spread your activity through the week. The scientific data on the relationship between total volume (frequency x duration x intensity) of activity and health benefits are more convincing and consistent than those for frequency, duration or intensity of activity. Optimal benefits (ie in of effort required, for health gain) are gained in the range from around 500 to around 1000 MET.min/week of physical activity. 500 MET.min/week is equivalent to 150 minutes of activity, or 75 minutes of vigorous activity, or any combination of intensity and duration that provides this amount of activity. 1000 MET.min/week is equivalent to 300 minutes of moderate intensity or 150 minutes of vigorous activity (or a combination). THREE Accumulate at least 150 minutes of moderate intensity physical activity (including brisk walking) or 75 minutes of vigorous activity, or an equivalent combination of moderate and vigorous activities, each week.
For most health outcomes, additional benefits occur with more physical activity. In particular, more activity is required for the prevention of weight gain and some cancers. This higher amount of physical activity can be achieved by longer duration (more minutes) or greater frequency (more often) or higher intensity (more effort). * The MET (metabolic equivalent) is the unit used to define activity intensity or effort, in multiples of resting metabolic rate. One MET is defined as energy expenditure at rest, usually equivalent to 3.5mL of oxygen uptake per kg of body weight per minute. 500 MET.min/week is equivalent to 150 minutes of physical activity at 3.33 MET (moderate intensity) or 75 minutes of physical activity at 6.66 MET (vigorous). of Evidence = A Any combination of moderate and/or vigorous intensity activities can be included, with each minute of vigorous physical activity 'counting' as two minutes of moderate intensity activity. THREE Evidence relating to the optimal frequency of physical activity each week is equivocal. The repeated physiological and metabolic adaptations, and energy expenditure associated with daily physical activity, make it likely that frequent activity is more beneficial than activity on only one Be active on most, preferably all, days every week