Physical activity Sedentary behaviour and Body mass Dr CK Student Copy 23-24.pptx

Physical activity, Sedentary behaviour and Body mass Dr Chiranjeevi [email protected] Where opportunity creates success  UM1010: Learning Outcomes Define physical activity, exercise and sedentary behaviours. Identify the factors that influence physical activity and sedentary behaviour...

Physical activity, Sedentary behaviour and Body mass Dr Chiranjeevi [email protected] Where opportunity creates success  UM1010: Learning Outcomes Define physical activity, exercise and sedentary behaviours. Identify the factors that influence physical activity and sedentary behaviour Understand the effects of physical activity and sedentary behaviour on all- cause mortality? Understand the relationship between physical activity and health conditions (for example, cardiovascular risk factors, type 2 diabetes, obesity, cancer and mental health). Determine the amount or dose of physical activity required to influence specific health parameters.  What we will be discussing today? The evidence for and against the use of physical activity as a means of regulating body mass Sedentary behaviour and how it relates to body mass regulation. The inner ring represents the main behaviour categories using energy expenditure. *Tremblay MS, Aubert S, Barnes JD, Saunders TJ, Carson V, The outer ring provides general Latimer-Cheung AE, Chastin SF, Altenburg TM, Chinapaw MJ. Sedentary behavior research network (SBRN)–terminology categories using posture. consensus project process and outcome. International journal of behavioral nutrition and physical activity. 2017 Dec;14(1):1-7.  Physical Activity Physical activity (PA) can be broadly defined as bodily movement produced by skeletal muscles. Any active movement of the body that is produced by muscular contractions and that results in the expenditure of energy Exercise refers to the subset of physical activity involving a structured program to improve physical fitness. Examples: various types of occupation, sport, errands and household chores  Physical Activity – How active are we? Health Survey for England Domination by Technology at home and at work. Increasing car use for travel Major contributing factors to lower levels of physical activity in the UK. Lack of physical activity is costing the UK an estimated £7.4 billion a year, including £0.9 billion to the NHS alone. Long term conditions such as *https://www.gov.uk/government/publications/health-matters-getting-every- adult-active-every-day/health-matters-getting-every-adult-active-every-day diabetes, cardiovascular and respiratory disease What counts as moderate physical activity?  Start small and build up gradually.  Just 10 minutes of moderate physical activity at a time provides physical and mental health benefits.  The link between physical inactivity and obesity is well established.  With more than half of adults in England currently overweight or obese, can benefit from being more active every day.  Low PA is one of the top 10 causes of disease and disability in England.  Persuading inactive people to become more active could prevent *https://www.gov.uk/government/publications/health-matters-getting-every- one in ten cases of stroke and heart adult-active-every-day/health-matters-getting-every-adult-active-every-day disease in the UK  Physical Activity - Health Benefits Regular physical activity has major preventive health benefits include reduced risk of all- cause mortality, coronary heart disease, hypertension, stroke, colon cancer, breast cancer, type 2 diabetes, and fall-related fractures The marginal benefit of even low physical activity is large, and the marginal benefit actually decreases with greater amounts of activity. The two most important types of health-enhancing physical activity are moderate- to vigorous-intensity aerobic activity. It has a curvilinear dose-response relationship, curvilinear dose–response relationship, indicating that low or moderate volumes of PA yield a large risk reduction, whereas further increases in exercise volumes produce smaller additional benefits. moderate- to vigorous-intensity muscle strengthening activity. Physical Activity - Health Benefits For people with T2DM, regular exercise is a highly effective addition to eating a healthy diet and standard medical treatment for improving insulin sensitivity and blood sugar levels. As a bonus, physical activity also helps with weight loss and blood pressure control. Exercise may also help prevent prediabetes from https://www.verywellhealth.com/cardio progressing. vascular-exercise-and-diabetes-108699 1 TYPE 2 DIABETES LIVING WITH A Guide to Exercise and Type 2 Diabetes By Debra Manzella, RN Physical Activity – Health Benefits According to the National Institute for Health and Care Excellence (NICE),  regular physical activity helps to prevent and manage over 20 chronic diseases, many of which are affecting people at an earlier age; 1 in 3 of the working age population have at least 1 long term condition and 1 in 7 have more *https://www.gov.uk/government/ than one. publications/health-matters-getting- every-adult-active-every-day/health- matters-getting-every-adult-active- every-day Dose-response gradient for physical activity and health The health benefits of physical activity are due to multiple, incompletely understood physiological effects. For example, physical activity reduces blood pressure in people with hypertension. Possible mechanisms include reducing sympathetic activity and increasing vagal tone, reducing norepinephrine levels, releasing vasodilators such as endorphins, reducing insulin resistance, reducing plasma renin levels, and preventing overweight and obesity. In adults with type 2 diabetes, the effects of physical activity on skeletal muscle include changes in contractile proteins isoforms, mitochondrial volume and functional capacity, metabolic regulation, intracellular signalling, and neuromuscular function. Dose-response gradient for physical activity and health *Gambardella J, Morelli MB, Wang XJ, Santulli G. Pathophysiological mechanisms underlying the beneficial effects of physical activity in hypertension. The Journal of Clinical Hypertension. 2020 Feb;22(2):291. Dose-response gradient for physical activity and health *Eckardt K, Görgens SW, Raschke S, Eckel J. Myokines in insulin resistance and type 2 diabetes. Diabetologia. 2014 Jun;57(6):1087-99.  Attributes & Measures of Physical Activity The primary attributes of physical activity are type (mode), frequency, duration, and intensity. Types of physical activity (e.g., walking, swimming, lifting, stretching) are grouped according to their main physiologic effects into well-known categories: aerobic (or “cardio”), muscle strengthening, flexibility, and balance. Intensity is the level of effort during activity. For aerobic activity, the absolute intensity is measured in metabolic equivalents (METs), with 1 MET being the resting metabolic rate, which is commonly taken to be 3.5 mL O 2 /kg/minute in adults.  Attributes & Measures of Physical Activity The relative intensity is measured as percentage of oxygen uptake reserve (aerobic capacity) required to perform an activity. In practice, heart rate is used to monitor relative intensity because of the generally linear relationship between heart rate and oxygen uptake. When the heart rate is not monitored, options for estimating relative intensity include the “talk test” and Rating of Perceived Exertion scale, where 6 equals no exertion and 20 equals maximal exertion. https://www.cdc.gov/ physicalactivity/basics/measuring/ exertion.htm  Criteria For Assessing Relative And Absolute Intensity Of Aerobic Activity *Physical Activity - Goldman-Cecil Medicine Buchner, David M.; Kraus, William E.; Goldman-Cecil Medicine, 13, 52-  Types of PA and MET’S *ACSM’S Guidelines for exercise testing and prescription. Physical Activity – Recommendations Physical activity guidelines for adults from the UK Chief Medical Officers. Moderate intensity physical activities, such as brisk walking or cycling, cause adults to get warmer and breathe harder and their hearts to beat faster, but they can still carry on a conversation. *https://www.gov.uk/government/ publications/health-matters-getting- every-adult-active-every-day/health- matters-getting-every-adult-active- every-day Physical Activity – Recommendations American College of Sports Medicine & Centres for Disease Control and Prevention  Sedentary Behaviour What is it? Sedentary behaviour is defined as any waking behaviour characterized by an energy expenditure ≤1.5 METs while in a sitting, reclining or lying posture. Sedentary behaviour includes those activities that imply an energy expense ≤ 1.5 METs, whilst physical inactivity is defined as an insufficient level of physical activity (PA) that does not meet current recommendations. Both behaviours have increased in recent years due to changes in the physical, social and economic environment of our current society i.e., “the obesogenic environment”.  Sedentary Behaviour (SB) Healthy adults can spend as much as 20 hours in a 24–hour period, sitting or lying down. Increased SB is now thought to be an independent risk factor for diseases. Physical activity level has stayed constant for many years, but sedentary activity has increased. It is not practical to suggest that a large proportion of sedentary time can be substituted with active time, as most job occupations involve a lot of sitting. It may, however be feasible to substitute a lot of our sedentary time with low-intensity physical activity (LIPA) e.g. standing up, moving around Is this useful for maintenance of body/fat mass?  Effects of low-intensity physical activity (LIPA) on skeletal muscle Skeletal muscle contains a variety of different type of muscle fibre, some are ‘slow oxidative’ and others are ‘fast glycolytic’ Slow oxidative fibres contain about 10 times the amount of lipoprotein lipase than fast glycolytic fibres Lipoprotein lipase is important for a healthy plasma lipoprotein profile, and reduces deposition of abdominal fat. Slow oxidative fibres are recruited more readily at lower activity intensity than fast glycolytic fibres – so LIPA will tend to recruit these fibres. This may form the basis for the health benefits resulting from *Bouchard C, Blair SN, Haskell WL. Physical activity and health. Human Kinetics; 2012 Feb 29. increased LIPA. *Bey L, Hamilton MT. Suppression of skeletal muscle lipoprotein lipase activity during physical inactivity: a molecular reason to maintain daily low‐intensity activity. The Journal of physiology. 2003 Sep;551(2):673-82.  LIPA and Sedentary Behaviour Patterns This study reported an effect of movement patterns on waist circumference and plasma lipid profiles In people with similar total amount of sedentary time, those who broke their time up into multiple sections (‘breakers’) had a lower waist circumference than those who took their activity in blocks followed by long periods of sedentary time (‘prolongers’) The relationship between waist circumference and breaking up of sedentary time was independent of exercise intensity This supports the idea that encouraging incorporation of much more LIPA at frequent intervals throughout the day (i.e. avoiding prolonged sitting time) may have a beneficial *Dunstan DW, Healy GM, Sugiyama T, Owen N. ‘Too Much Sitting’ and effects. Metabolic Risk – has modern technology caught up with us? US Endocrinology. 2009;5(1), 29-33.  Accelerometer-Measured Physical Activity and Sedentary Behaviour Patterns Four patterns of movement measured using accelerometers The level of activity is shown by the darkness of the colouring (black is inactive, white is extremely active) Low sedentary-high active pattern is the one that consumed most energy, and high sedentary – inactive consumed the least. High sedentary – high exercise pattern still includes a lot of sedentary hours. Low sedentary- low intensity active pattern may have more benefits to health. *Bouchard C, Blair SN, Haskell WL. Physical activity and health. Human Is Sedentary Behaviour Related to Cardiovascular Risk? A. Vascular structure and function: stiffness and intima-media thickness increase; endothelial function decreases. B. Body mass index increases. C. Cardiorespiratory fitness decreases. D. Blood pressure increases. E. Insulin resistance increases. F. BloodY, lipids *Carter S, Hartman Holder increase. S, Thijssen DH, Hopkins ND. Sedentary behavior and cardiovascular disease risk: mediating mechanisms. Exercise and sport sciences reviews. 2017 Apr 1;45(2):80-6. Summary of Sedentary Behaviour https://blog.lboro.ac.uk/news/health/sit-less-stand-tackling-office-sedentary- behaviour/ Healthy adults can spend as much as 20 hours in a 24–hour period, sitting or lying down.  Maintenance of body fat mass is dependent on energy balance  Food Intake in excess of energy expenditure = Positive Energy balance  Food intake less than energy expenditure = Negative energy balance  Dietary intake must be approximately equal to energy expenditure for homeostasis  Maintenance of body fat mass is dependent on energy balance  1lb (pound) of body fat is equivalent to In order to lose this mass of fat, 3500 kCal (14644kJ) one need to expend this number  1kg body fat is equivalent to 7700kCal of kCal/kJ more than (32217kJ) consumption. Activity kCal Duration need to lose Food kCal/ Amount /min 1lb per week 100g needed to gain 1lb per Weight 3.73 938 mins (15.6 hours) or week training 2 hours 12 mins per day Bananas (1) 65 (107) 32.7 Brisk 4.96 705 mins (11.75 hours) or bananas walking 1 hours 40 mins per day Bread (1 slice) 240 (96) 36 slices Aerobics 8.6 406 mins (6.78 hours) or 58 mins per day Low fat yoghurt 48 (80) 43.8 pots (small pot) Swimmin 12.4 282 mins(4.70 hours) or Crisps (small 536 18 bags g 40 mins per day bag) (188)  Can exercise alone result in weight loss? There is a body of research supporting weight loss due to exercise alone but each one needs careful consideration Needs reviewing in terms of cohort, outcome measures etc. Aerobic exercise alone results in clinically significant weight loss for men and women: Midwest Exercise Trial-2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3630467/ The objective of this RCT was to evaluate the effect of aerobic exercise, without energy restriction, on weight loss in sedentary overweight and obese men and women. Supervised exercise, with equivalent energy expenditure, results in clinically significant weight loss with no significant difference between men and women. There have also been studies that showing physical activity alone CAN result in fat loss The results below show that a reduction in body fat is related to the amount of exercise undertaken in middle aged women with no restriction on kCal consumed (these data are averages from 18 randomised controlled trials) Someone expending around 5000 kCal per week, or doing exercise for about 500 min per week could expect to lose approx. 0.5-0.7 kg of body weight and fat per week (Ross & Janssen 2001). In response to well-controlled, short-term trials, increasing physical activity expressed as energy expended per week is positively related to reductions in body weight and total adiposity in a dose- There have also been studies that showing physical activity alone CAN result in fat loss *Ross R, Janssen IA. Physical activity, total and regional obesity: dose-response considerations. Medicine and science in sports and exercise. 2001 Jun 1;33(6; There have also been studies that showing physical activity alone CAN result in fat loss Data from another study involving a group of 464 women who were randomly assigned to an exercise programme of 4kCal/kg per week, 8kCal/kg per week or 12kCal/kg per week for 6 months (for a 75kg person, that is 300, 600 and 900kCal per week) The exercise intensity was the same for everyone – heart rate at an exercise level corresponding to 50% of VO2max There have also been studies that showing physical activity alone CAN result in fat loss Women exercising at lower exercise doses lost more weight than predicted. At the highest exercise dose, they lost less than predicted, suggesting that they overcompensated by eating more. Suggests a physiological stress response at higher exercise levels There have also been studies that showing physical activity alone CAN result in fat loss Some people are ‘non-responders’ to exercise interventions, i.e. they do not lose weight; this may be due to factors related to this stress response. Compared with the control group, the VO2 increased by 4.2% in the 4-kcal/kg, 6.0% in the 8-kcal/kg, and 8.2% in the 12- kcal/kg per week groups.  Compensation to energy lost in physical activity It is often believed that increasing physical activity by a moderate amount increases hunger, and participants compensate by eating more In fact, individuals who increase their physical activity level by up to 1000kCal/day do not see any change in hunger for 2 weeks After 2 weeks on a physical activity programme, hunger and appetite increases by around 30% (varies widely between individuals from 0 to 100%) There is no compensation for a reduction in energy expenditure i.e. individuals do not naturally reduce their hunger and appetite if they become sedentary.  How much activity is required to prevent weight gain? Body mass increases in both men and women with age Contributing factors: gradual fall in resting metabolic rate BMI reduction in physical activity level due to fall in leisure time, Age (years) increase in sedentary pursuits and hobbies, Data source: health survey for England decrease in occupational 2017  How much activity is required to prevent weight gain? PAL = Physical Activity Level PAL - is a way to express a person's daily physical activity as a number, and is used to PAL PAL Walking Approx. estimate a person's total energy expenditure. Category value duratio walking n distance Consensus is that a PAL of 1.7-1.8 is needed to (mins) (miles) prevent age-related weight gain Sedentary 1.0-1.39 0 0 Low 1.4 – 33-44 2.2 Individuals need to be in the ‘active’ category active 1.59 i.e. do the equivalent of approximately 7.3 Active 1.6 – 109-146 7.3 miles per day 1.89 Very 1.9-2.5 for250-334 *National Institute 16.7 Health and Care This varies according to the body mass of the Excellence active (NICE) guidelines. person – a heavier person needs to do less to expend the same amount of energy.  Some factors of interest Increasing physical activity without altering energy intake DOES result in fat loss The fat loss occurs in a dose-dependent manner based on time spent exercising and the energy expended doing so. The currently recommended amount of exercise needed to lose fat is more than 30 minutes per day, 5 days in a week. Other trials have found that even when there is no loss of body mass (participants increase their energy intake to compensate for that expended during exercise), exercise reduces waist circumference significantly, and this is likely to correlate with a loss of abdominal fat and reduces all cause-mortality.  A lot of research studies that have demonstrated that physical activity alone does not result in fat loss Some studies did not control energy intake Some studies relied on self-report measures (very unreliable) In some studies, people feel they need to eat more than usual, and may overcompensate. Some people may feel that they are tired, or have earned a rest (therefore being less active for more of the day). Results are complicated by the propensity of some individuals to overcompensate (by eating) more than other. Covid lifestyle restrictions Mechanisms by which they can lead to reduced muscle protein synthesis and increased muscle protein breakdown resulting in muscle loss. The development of sarcopenia, or in the presence of caloric excess, sarcopenic obesity, is associated with a significantly increased risk of multiple comorbidities, some of which may also increase the risk of COVID- 19 infection and severity.  OVERALL SUMMARY In order to lose fat mass, one need to expend more than consume. Even low levels of activity are important for fitness and health One might NOT lose fat mass with physical activity alone. Some research has demonstrated that physical activity alone does not result in fat loss Calorie restriction and modified diet should be added to physical activity However, well controlled studies have shown an effect Age associated weight gain is controlled by being ‘Active’  OVERALL SUMMARY Physical inactivity or Insufficient physical activity (PIA) is a public health concern and a major risk factor for early mortality and common chronic diseases including obesity, metabolic syndrome, insulin resistance, type 2 diabetes (T2D), certain type of cancers, mental health disorders and others. Sedentary behaviours (SBs) are distinct from physical inactivity and corresponds to ‘any waking behaviour characterized by an energy expenditure