Eating to win: activity, diet and weight control

Transcription

1 Eating to win: activity, diet and weight contro

2 About this free course This OpenLearn course provides a sampe of eve 1 study in This version of the content may incude video, images and interactive content that may not be optimised for your device. You can experience this free course as it was originay designed on OpenLearn, the home of free earning from The Open University There you aso be abe to track your progress via your activity record, which you can use to demonstrate your earning. Copyright 2017 The Open University Inteectua property Uness otherwise stated, this resource is reeased under the terms of the Creative Commons Licence v4.0 Within that The Open University interprets this icence in the foowing way: Copyright and rights faing outside the terms of the Creative Commons Licence are retained or controed by The Open University. Pease read the fu text before using any of the content. We beieve the primary barrier to accessing high-quaity educationa experiences is cost, which is why we aim to pubish as much free content as possibe under an open icence. If it proves difficut to reease content under our preferred Creative Commons icence (e.g. because we can t afford or gain the cearances or find suitabe aternatives), we wi sti reease the materias for free under a persona enduser icence. This is because the earning experience wi aways be the same high quaity offering and that shoud aways be seen as positive even if at times the icensing is different to Creative Commons. When using the content you must attribute us (The Open University) (the OU) and any identified author in accordance with the terms of the Creative Commons Licence. The Acknowedgements section is used to ist, amongst other things, third party (Proprietary), icensed content which is not subject to Creative Commons icensing. Proprietary content must be used (retained) intact and in context to the content at a times. The Acknowedgements section is aso used to bring to your attention any other Specia Restrictions which may appy to the content. For exampe there may be times when the Creative Commons Non- Commercia Shareaike icence does not appy to any of the content even if owned by us (The Open University). In these instances, uness stated otherwise, the content may be used for persona and noncommercia use. We have aso identified as Proprietary other materia incuded in the content which is not subject to Creative Commons Licence. These are OU ogos, trading names and may extend to certain photographic and video images and sound recordings and any other materia as may be brought to your attention. Unauthorised use of any of the content may constitute a breach of the terms and conditions and/or inteectua property aws. We reserve the right to ater, amend or bring to an end any terms and conditions provided here without notice. A rights faing outside the terms of the Creative Commons icence are retained or controed by The Open University. Head of Inteectua Property, The Open University 2 of 26 Thursday 30 November 2017

3 Contents Introduction 4 Learning Outcomes 5 1 Physica activity and dieting 6 2 Physica activity and appetite 9 3 Fitness and fat metaboism 10 4 Diet, exercise and choestero 11 5 Eating for performance; before, during and after exercise The roe of the gycaemic index Eating before exercise Eating during exercise Eating post-exercise 15 6 Hydration: water and sports drinks Water intake Hydration before, during and after exercise Sports drinks 20 Concusion 22 Keep on earning 23 References 24 Acknowedgements 25 3 of 26 Thursday 30 November 2017

4 Introduction Introduction Wecome to this free course; Eating to win: activity, diet and weight contro. This subject has become a hot topic for the genera pubic because of its importance for good heath. It is aso a key consideration for athetes needing to optimise their training and performance. This course wi expore the inks between physica activity, diet and weight contro through a range of interactive activities and resources. You wi compare physica activity and dieting as weight contro methods and discuss the reative benefits of physica activity for weight management. You wi aso ook at the importance of effective nutrition and hydration before, during and after exercise; because what you eat and drink can have a significant effect on sport and exercise performance. This OpenLearn course provides a sampe of eve 1 study in Sport. You might be particuary interested in the Open University course E117 Introduction to sport and fitness. 4 of 26 Thursday 30 November 2017

5 Learning Outcomes After studying this course, you shoud be abe to: recognise the importance of physica activity in weight management compare physica activity and dieting as weight contro methods understand the importance of pre, during and post-exercise nutrition and hydration.

6 1 Physica activity and dieting 1 Physica activity and dieting Figure 1 An exercise bike fitness cass There is a cear reationship between reguar participation in physica activity and heathy measures of body composition and body fat. However, the number of peope participating in adequate eves of physica activity remains reativey ow. For exampe, in Engand just 60% of aduts participate in the recommended 150 minutes of moderate physica activity each week (Sport Engand, 2016a) and ony around 40% of men and 30% of women participate in sport, at moderate intensity, for at east 30 minutes on one or more days a week (Sport Engand, 2016b). According to Weinberg and Goud (2015) the main reasons given by aduts for not participating in physica activity are ack of time, ack of motivation, ack of energy and heath-reated issues. If we can overcome these barriers, participation in physica activity can provide severa key benefits for our heath (see Figure 2), such as maintaining a heathy weight and reducing the risk of diseases such as Type II Diabetes (Department of Heath, 2011). 6 of 26 Thursday 30 November 2017

7 1 Physica activity and dieting Figure 2 Physica Activity Infographic (Department of Heath, 2011) Physica activity infuences appetite and eads to improved overa fitness eves. In turn, higher fitness eves mean you gain advantages that benefit your weight contro, due to the increased use of body fat as an energy source and the preservation of ean musce mass. One of the major physioogica advantages of exercise is that eves of fat in the bood are reduced. In the first activity, you wi examine the infuence of exercise on weight contro compared with dieting. 7 of 26 Thursday 30 November 2017

8 1 Physica activity and dieting Activity 1 Physica activity and weight contro Aow about 30 minutes In this reading activity, you wi earn about the infuence of exercise on weight contro compared with dieting. Read from Activity and weight contro up to, but not incuding, Exercise and appetite on pages from Chapter 13 of the book Fitness and Heath by Sharkey and Gaski (2013). As you read, answer the foowing questions: 1 What is the key message about the effectiveness of diet and exercise for weight contro? 2 What are the exercise recommendations for effective weight contro? 3 Why might exercise be more effective for weight contro than dieting aone? Provide your answer... Discussion 1 The key message conveyed by the authors is that, for weight contro, neither exercise nor diet aone resut in the same eve of ong-term success as exercise combined with diet. 2 The energy used during activity is reated to severa factors, incuding the duration and intensity of exercise. For effective weight contro, Sharkey and Gaski (2013) recommend moderate rather than high intensity exercise because more caories are used before exhaustion is reached. Others suggest that the tota energy expenditure (duration and intensity) is most important. Sharkey and Gaski (2013) aso emphasise that greater fitness aows more activity and therefore more effective weight contro; hence exercise frequency may be more important than intensity. 3 Sharkey and Gaski (2013) concude that exercise and dieting combined is more effective than dieting aone. They refer to severa studies which show that physica activity shoud be a key component of successfu weight contro programmes. This is because restricting caorie intake aone, by dieting, eads to a oss of ean tissue (musce mass) and body water in addition to fat. They emphasise that when the body oses ean tissue it becomes ess abe to burn caories due to the decreased metaboic rate, and so when energy intake increases again, fat is regained more easiy than prior to the caorie-restricted diet. Weight oss with exercise aows the decine in body fat eves without the accompanying oss of ean tissue. Indeed, exercise wi increase ean tissue and thus increase basa metaboic rate (BMR). There is aso the effect of excess postexercise oxygen consumption (EPOC), where caorie expenditure remains high for a short whie after the period of exercise (the recovery period). Having examined the importance of physica activity for weight contro you wi now ook at the ink between physica activity and appetite. 8 of 26 Thursday 30 November 2017

9 2 Physica activity and appetite 2 Physica activity and appetite Figure 3 It s time to eat Food intake and physica activity are the two key components in energy baance (the baance of caories consumed through eating and drinking compared to caories used through physica activity). Appetite is a compex phenomenon and is infuenced by severa factors. In the brain, within a region caed the hypothaamus, is the contro centre for food intake, the appestat. Many psychoogica factors infuence the desire to eat. Physioogica factors, such as bood sugar eves and hormones, aso infuence the appestat. It is argued that reguar exercise heps the appestat to adjust caorie intake to correspond to energy expenditure. Our food intake may be infuenced by the duration, intensity and frequency of exercise. Exercise before eating may inhibit the appetite and increase fat metaboism, since the metaboic rate remains high immediatey after exercise (Sharkey and Gaski, 2013). We previousy mentioned the effect of excess post-exercise oxygen consumption (EPOC) on caorie expenditure. Post-exercise may be the best time to eat a mea if weight oss is the goa. Studies have shown that exercise either just before or after a mea is aso effective in reducing ipidaemia or ipaemia (the presence of fat in the bood), which is associated with atheroscerosis (the deveopment of fatty paques in the arteries). Therefore, a post-mea wak or other physica activity is abe to reduce ipidaemia by increasing fat utiisation. Eating food over severa periods in the day (three to six), that is, itte and often instead of eating a coupe of arger meas, has been suggested to ower bood ipid and choestero eves, since the metaboism of the fat eaten wi occur over a onger period (Sharkey and 9 of 26 Thursday 30 November 2017

10 3 Fitness and fat metaboism Gaski, 2013). In contrast, avoiding meas wi ower the metaboic rate and so bood ipids (i.e. choestero eves) wi increase. In the next section, you wi expore the ink between fitness and fat metaboism. 3 Fitness and fat metaboism Fitness eves contribute to our energy expenditure and weight contro. As fitness improves it is possibe to do more work at the same heart rate and eve of perceived exertion; you are abe to burn more energy for the same perceived effort. The term metaboism means the breakdown of foods to reease energy. You can metaboise fat, carbohydrate or protein to reease energy. In the foowing activity, you wi earn about the ink between fitness eve and fat metaboism. Activity 2 Fitness and fat Aow about 30 minutes Read from Increased caoric expenditure up to, but not incuding, the subsection Reduced bood ipids on pages from Chapter 13 of the book Fitness and Heath by Sharkey and Gaski (2013). As you read, answer the foowing questions: 1 What is the ink between increased fitness and caoric expenditure? 2 What is the reationship between actic acid and the use of fatty acids as a source of energy? Provide your answer... Discussion 1 As your fitness eve improves your caoric expenditure increases. This is because you generay increase your frequency, duration and intensity of exercise. 2 At high intensities of exercise, fat and carbohydrate cannot be broken down quicky enough to provide energy, so carbohydrates are metaboised to provide the energy needed quicky, resuting in increases of actic acid. The presence of actic acid aso bocks the action of epinephrine (adrenain), which is needed to aow the fatty acids to be used as energy. When your fitness improves, you are abe to perform exercise at a higher intensity with ess of an increase in actic acid. This means that you are more abe to utiise fat as an energy source. Having expored how improved fitness can enabe us to metaboise fat, you wi now ook at the effects of diet and exercise on fats in the bood. 10 of 26 Thursday 30 November 2017

11 4 Diet, exercise and choestero 4 Diet, exercise and choestero Choestero is a type of fat that is often given bad press due to its roe in deveoping Coronary Heart Disease (CHD). However, it is produced and used by the body for a range of functions. In fact, choestero is so important that it is produced by the iver to meet your daiy needs. If you consume foods containing choestero though, your iver wi make ess to compensate for this. The probem comes when you consume more than is needed to meet the requirements of the body. Choestero performs the foowing functions: heps to form the structure of the ce membranes produces bie, which aids fat digestion produces steroid hormones such as oestrogen and testosterone produces vitamin D from sunight. Choestero is found in the same foods as saturated fats. Meat, poutry, egg yoks, seafood and dairy products are a sources of choestero. Low-density ipoproteins (LDLs) carry choestero from the iver to the tissues where it is needed. High-density ipoproteins (HDLs) are responsibe for the remova of surpus LDLs from the tissues to be taken back to the iver for disposa (Figure 4). Therefore, HDLs are regarded as good choestero and LDLs as bad choestero. Figure 4 The function of the iver in processing choestero Bood choestero eve is measured in miimoes per itre (mmo/), and this can be measured through a simpe bood test. There is cause for concern if the measure of bood choestero is over 5.2 miimoes per itre. However, it is important to know the ratio of LDLs to HDLs as we: it shoud be 75 per cent LDL to 25 per cent HDL. If the amount of LDL is more than 75 per cent, then there is aso an increased risk of CHD. It is possibe to have a ow bood choestero eve but sti be in danger if the HDL count is ess than 25 per cent. There are cear guideines as to what are acceptabe choestero eves and eves associated with an increased risk of CHD. These eves are shown in Tabe 1. Excess amounts of choestero in the bood can increase the risk of choestero being deposited onto the artery was. As the choestero is aid down in the artery was, the artery space wi start to narrow and it wi cause a hardening of the artery wa. The resuting oss of 11 of 26 Thursday 30 November 2017

12 5 Eating for performance; before, during and after exercise easticity to the artery wa and smaer space to transport bood is the start of CHD and can cause angina. Tabe 1 Risk of coronary heart disease with increasing bood choestero eves Bood choestero eve (mmo/) < >7.5 Risk of CHD Low Increased Moderate High HDL count is increased by taking reguar exercise and is owered by smoking and increasing exposure to poution. LDL count is raised through excess acoho intake and high consumption of foods rich in saturated fat. In the foowing activity, you wi earn about the effects of diet and exercise on bood ipids. Activity 3 Bood ipids Aow about 30 minutes Read from Reduced bood ipids up to, but not incuding, the subsection Increased ean tissue on pages from Chapter 13 of the book Fitness and Heath by Sharkey and Gaski (2013): As you read, answer the foowing question: 1 What effect does diet and exercise have on the bood ipids - trigycerides and choestero? Provide your answer... Discussion 1 Both dieting and exercise can reduce bood pasma trigyceride eves. Exercise enhances the remova of trigyceride from the circuation and increases its utiisation in the musce ces. Exercise aso heps to shift the baance or profie of ipoproteins in the bood, raising HDL and owering LDL. Therefore, reguar physica activity provides a very substantia heath benefit. In the next section, you wi move on to consider the importance of nutrition before, during and after exercise. 5 Eating for performance; before, during and after exercise In this section you wi expore the impact of food before, during and after exercise. 12 of 26 Thursday 30 November 2017

13 5 Eating for performance; before, during and after exercise 5.1 The roe of the gycaemic index The gycaemic index (GI) describes the rate at which carbohydrate foods are digested (broken down into gucose) and enter the boodstream as gucose. You may aready be aware of GI in the context of weight oss diets and heathy eating. The GI aso has an important roe in maintaining energy eves for physica activity and sports performance. The GI is a ranking of foods from zero to 100, based on the rate at which a carbohydrate food is broken down into gucose and enters the boodstream, resuting in a rise in the bood gucose eve. Pure gucose has a GI of 100 and serves as a reference point to which a carbohydrate foods are compared. A food that has a GI of 55 or over is regarded as high GI and food that has a GI of ess than 55 is regarded as ow GI (The University of Sydney, 2017). Figure 5 shows the change in bood gucose eves over time in response to the intake of high and ow GI foods. Cick on High GI and Low GI for an expanation of each one. Interactive content is not avaiabe in this format. Figure 5 Bood gucose eves over time in response to ow and high GI food Some exampes of high, moderate and ow GI foods are shown in Tabe 2. Tabe 2 High, moderate and ow gycaemic index foods High GI Moderate GI Low GI Gucose 100 Cornfakes 81 Potato (boied) 56 Parsnips 97 Chips 75 Sweet potato 54 French baguette 95 Bage 72 Bananas 52 Lucozade Origina 95 Watermeon 72 White pasta 50 Honey 87 Whoemea bread 71 Muesi 49 Potato (baked) 85 White bread 70 Porridge oats 49 Sports drinks 70 Baked beans 48 Weetabix 66 Appes 38 White rice 64 Yogurt 36 Shredded Wheat 64 Chickpeas 28 Raisins 64 Whoe mik 27 Cherries 22 Fructose 20 (Source: Adapted from Bean, 2006) 5.2 Eating before exercise To prepare for exercise, high-carbohydrate meas and snacks are needed to maximise musce gycogen (gucose units inked together) stores. Pre-exercise meas shoud 13 of 26 Thursday 30 November 2017

14 5 Eating for performance; before, during and after exercise consist of ow to moderate GI carbohydrates with sma amounts of protein and some vitamins and mineras, for exampe, a chicken saad sandwich made with whoemea bread. The American Coege of Sports Medicine (ACSM) (2016) recommends that for genera fueing up for exercise of ess than 90 minutes an athete shoud consume 7 12 g/kg bodyweight per 24 hours. In the four hour period before exercise an athete shoud consume 1 4 g/kg bodyweight. If an athete is preparing for greater than 90 minutes of sustained or intermittent exercise they shoud consume g/kg bodyweight in the two day period eading up to the session. 5.3 Eating during exercise Both intermittent high intensity exercise and proonged moderate exercise can depete musce gycogen stores. If you consume carbohydrate during exercise this wi hep maintain your bood gucose eves, avoid musce gycogen depetion and provide performance benefits. Figure 4 shows the guideines for carbohydrate intake during exercise of increasing duration, from 30 minutes of exercise up to utra-endurance exercise asting over 2.5 hours (Jeukendrup, 2014). Figure 6 Carbohydrate intake guideines during exercise (adapted from Jeukendrup, 2014) 14 of 26 Thursday 30 November 2017

15 6 Hydration: water and sports drinks The guideines show that the amount of carbohydrate required per hour increases as exercise duration increases. For utra-endurance events (i.e. over 2.5 hours) the recommendation is to consume a arger amount of carbohydrates to ensure an optima suppy into the boodstream over time. Interestingy, for shorter duration exercise the guideines suggest that just rinsing the mouth with a carbohydrate drink can be beneficia for exercise performance. The carbohydrate intake guideines can be achieved by consuming high GI drinks, ges and soid foods (e.g. bars ow in fat, protein, and fibre). A mix-and-match strategy, based on persona preference, can be used to achieve carbohydrate intake goas. However, the carbohydrate intake shoud be baanced with appropriate fuid intake. 5.4 Eating post-exercise Refueing after exercise is vita to repair the damage caused by the exercise session and to enabe the body to be in an optimum state for the next training session. The ength of time that recovery wi take depends on the foowing: how depeted the gycogen stores have become the amount of musce damage the timing of the post-exercise mea. The important aspect of post-exercise recovery is the repacement of carbohydrate.the ACSM (2016) recommends that in situations with ess than eight hours of recovery between two fue demanding sessions an athete shoud consume g carbohydrate/ kg bodyweight per hour for the first four hours and then resume daiy fue needs after this period. In order to give the musces access to gucose quicky, it is recommended that some high GI carbohydrates are eaten during this period, particuary in the first two hours. This is why athetes might consume foods such as Jaffa cakes, sports drinks, crunch bars, bages with jam and raisins immediatey after exercise. Research shows that musce protein turnover is highest foowing exercise and it is therefore important to consume sufficient protein to repair and buid new musce. A range of g protein/kg bodyweight per day shoud be consumed (ACSM, 2016). If possibe, protein shoud be consumed from anima sources rather than pant-based sources because they have better absorption rates. Good sources of protein incude meat, fish, poutry, eggs and mik. Having examined the importance of nutrition and nutritiona recommendations for exercise performance, you wi now expore the essentia concept of hydration. 6 Hydration: water and sports drinks In this section you wi consider the importance of hydration as we as the effects of dehydration. 15 of 26 Thursday 30 November 2017

16 6 Hydration: water and sports drinks 6.1 Water intake Water pays a key roe in sustaining ife and in the effective performance of your mind and body. The adut mae and femae body consists of around 60 and 50 per cent water, respectivey. Approximatey two itres of water are ost from the body every day, but this wi vary depending on factors such as activity eve and environmenta conditions. Genera hydration guideines suggest that men shoud consume two itres (about ten 200 m gasses) of fuid per day and women shoud consume 1.6 itres (about eight 200 m gasses) of fuid per day (British Nutrition Foundation, 2017). An active person in a hot cimate may need to consume between five and ten itres a day (McArde et a., 2012). Figure 7 shows the ways in which the body gains and oses water. You can aso scro over the parts of the body on the diagram to view some of the effects of dehydration (when water oss exceeds intake) in different parts of the body. Interactive content is not avaiabe in this format. Figure 7 Water intake and oss Some of the effects of dehydration (when water oss exceeds intake) incude: dizziness and headache rapid heartbeat and impaired cardiac function reduced bood fow to the musces impaired kidney function decreased abiity to sweat oss of musce gycogen stores. During physica activity dehydration resuts from sweating, so it is important to ensure that the body is sufficienty hydrated before and during exercise. Fuid oss must aso be repaced to rehydrate the body after exercise and to prevent further dehydration. In the foowing activity, you wi expore fuid repacement strategies and how fuid intake can be combined with carbohydrate intake for energy repacement. Activity 4: Think about your drink! Aow about 20 minutes Watch the fim How beverage composition affects athetic performance which introduces you to fuid and carbohydrate repacement strategies. As you watch the fim, answer the foowing questions: 1 What are the three main phases of fuid repacement? 2 What factors can affect individua sweating rates? 3 What types of drinks are recommended for fuid and carbohydrate repacement? Provide your answer... Discussion 16 of 26 Thursday 30 November 2017

17 6 Hydration: water and sports drinks 1 The three main phases of fuid repacement are fuid intake (getting fuid into the body for hydration), fuid deivery (repacement of fuid oss or rehydration) and retention (keeping fuid in the body). 2 Significant dehydration (more than 2 per cent weight oss) impairs the body s abiity to reguate temperature and can decrease endurance and team sport performance. Sweating rates can be affected by factors such as genetics, exercise intensity and environmenta conditions (i.e. temperature, wind and humidity). 3 For exercise asting an hour or onger, g carbohydrate per hour is recommended for fue. A drink formuated with a 6 7 per cent soution of matodextrin, sucrose or gucose can exit the stomach and absorb into the boodstream as quicky as water. For endurance athetes exercising over 2 3 hours it is recommended that a sma amount of fructose is added to the soution. Higher carbohydrate drinks can be more beneficia for endurance athetes up to a certain point, however beyond this returns diminish and can even become negative because of sower absorption and potentia for increased gastrointestina distress. It is aso important to incude the eectroyte sodium in the drink because it heps to maintain bood sodium eves and promotes the retention of water in the body. 6.2 Hydration before, during and after exercise Athetes wi have individua needs and goas but there are some genera guideines for hydration before, during and post-exercise. Before exercise 17 of 26 Thursday 30 November 2017

18 6 Hydration: water and sports drinks Figure 8 Hydrating before exercise Athetes shoud consume a fuid voume equivaent to 5 10 m/kg bodyweight in the two to four hours before exercise (ACSM, 2016). During exercise 18 of 26 Thursday 30 November 2017

19 6 Hydration: water and sports drinks Figure 9 Staying hydrated Sweat rates vary during exercise, but most athetes and athetic events wi require an intake of 0.4 to 0.8 itres/hour (ACSM, 2016). Post-exercise 19 of 26 Thursday 30 November 2017

20 6 Hydration: water and sports drinks Figure 10 Rehydration after exercise In the post-exercise period, sweat and urine osses continue and effective rehydration requires the intake of a greater voume of fuid than the fina fuid deficit. It is recommended that the athete consumes itres of fuid for every 1 kg bodyweight ost (ACSM, 2016). 6.3 Sports drinks If an individua is appropriatey fueed, water may be adequate for activities of ess than one hour. In addition to water, there are three types of sports drink which can be used for a combination of hydration and energy repacement: hypotonic, hypertonic and isotonic. Hypotonic sports drinks 20 of 26 Thursday 30 November 2017

21 6 Hydration: water and sports drinks Figure 11 Hypotonic sports drink For events of a ong duration, hypotonic sports drinks which suppy some carbohydrate may be preferred to water. They have a ower concentration of partices than body fuids (ess than 4 g carbohydrate per 100m); meaning that they are absorbed into the body more quicky than water. Hypotonic sports drinks aso contain the eectroytes sodium and potassium, which contro the fow of water in and out of ces and are vita to ensure absorption. Hypertonic sports drinks Figure 12 Hypertonic sports drink Hypertonic sports drinks contain more than 8 g of carbohydrate per 100 m.they increase the amount of carbohydrate fue that can be suppied to the musces, but that wi aso 21 of 26 Thursday 30 November 2017

22 Concusion decrease the rate at which water is avaiabe because it sows the rate at which the contents of the stomach empties into the sma intestine. Isotonic sports drinks Figure 13 Isotonic sports drink Isotonic sports drinks have the same concentration of dissoved partices as body fuids (5 7 g carbohydrate per 100 m). They are a good choice because they contribute to the carbohydrate needed post-exercise. They aso contain the eectroytes, sodium and potassium. They are considered beneficia for use by athetes for events of one hour or more in duration.these drinks are beneficia for endurance sports because they provide a source of fue (usuay gucose sucrose, gucose poymer or matodextrin) in addition to water to reduce dehydration. Isotonic drinks are absorbed as fast as, or faster than, water aone. The decision to use hypotonic, hypertonic or isotonic drinks wi depend on whether the athete s goa is to promote hydration, carbohydrate uptake or a baance of both. Concusion In this free course, Eating to win: activity, diet and weight contro, you focused on why it is particuary important to use physica activity in combination with dieting as a means of achieving and maintaining a heathy weight. You aso expored how physica activity can impact on our appetite and how diet and exercise can infuence fat metaboism. Finay, you ooked at effective eating and drinking strategies to optimise sport and exercise performance. You shoud have achieved the earning outcomes isted beow. If there are any you fee you have not achieved, you shoud read back over the reevant sections of this course. On competion of this course you shoud be abe to: recognise the importance of physica activity in weight management 22 of 26 Thursday 30 November 2017

23 Keep on earning compare physica activity and dieting as weight contro methods understand the importance of pre, during and post-exercise nutrition and hydration. The main earning points for this course are: Physica activity shoud be incuded in weight oss programmes as it minimises osses of ean body mass. Physica activity may hep to inhibit appetite. An increased fitness eve enabes the utiisation of fat as an energy source and greater caoric expenditure. Exercise eads to a decrease in bood eves of trigycerides and LDL and an increase in HDL. The GI of food has an important roe in maintaining energy eves for physica activity and sports performance. Low to moderate GI carbohydrate shoud be consumed before exercise to promote sustained energy reease. High GI carbohydrate shoud be consumed during exercise to minimise gycogen depetion. High GI carbohydrate shoud be consumed post-exercise to rapidy repenish gycogen stores. It is important to maintain hydration eves before, during and after exercise to optimise performance and recovery. There are three types of sports drinks which can be used to provide hydration and energy repacement: hypotonic, hypertonic and isotonic. This OpenLearn course provides a sampe of eve 1 study in Sport. You might be particuary interested in the Open University course E117 Introduction to sport and fitness. Keep on earning 23 of 26 Thursday 30 November 2017

24 References Study another free course There are more than 800 courses on OpenLearn for you to choose from on a range of subjects. Find out more about a our free courses. Take your studies further Find out more about studying with The Open University by visiting our onine prospectus. If you are new to university study, you may be interested in our Access Courses or Certificates. What s new from OpenLearn? Sign up to our newsetter or view a sampe. For reference, fu URLs to pages isted above: OpenLearn Visiting our onine prospectus Access Courses Certificates Newsetter References American Coege of Sports Medicine (ACSM), American Dietetic Association (ADA) and Dieticians of Canada (DC) (2016) Joint position statement, nutrition and athetic performance, Medicine and Science in Sports and Exercise, vo. 48, no. 3, pp Bean, A. (2006) The Compete Guide to Sports Nutrition, London, A & C Back. British Nutrition Foundation (2017) Heathy Hydration Guide [Onine]. Avaiabe at (Accessed 9 March 2017). 24 of 26 Thursday 30 November 2017

25 Acknowedgements Department of Heath (2011) Physica activity benefits for aduts and oder aduts [Onine]. Avaiabe at Physica_activity_infographic.PDF (Accessed 15 May 2017). Jeukendrup, A. E. (2014) A step towards personaised sports nutrition: carbohydrate intake during exercise, Sports Medicine, vo. 44, no. 1, pp McArde, W. D., Katch, F. I. and Katch, V. L. (2012) Sports and Exercise Nutrition, 4th edn, Batimore, Lippincott, Wiiams and Wikins. Sharkey, B. J. and Gaski, S. E. (2013) Fitness & Heath, 7th edn, Leeds, Human Kinetics. Sport Engand (2016a) Active Lives Survey [Onine]. Avaiabe at (Accessed 15 May 2017). Sport Engand (2016b) Active peope Survey [Onine]. Avaiabe at (Accessed 15 May 2017). The University of Sydney (2017) About Gycemic Index [Onine]. Avaiabe at (Accessed 9 March 2017). Weinberg, R. and Goud, D. (2015) Foundations in Sport and Exercise Psychoogy, 6th edn, Leeds, Human Kinetics. Acknowedgements Except for third party materias and otherwise stated (see terms and conditions), this content is made avaiabe under a Creative Commons Attribution-NonCommercia-ShareAike 4.0 Licence. The materia acknowedged beow is Proprietary and used under icence (not subject to Creative Commons Licence). Gratefu acknowedgement is made to the foowing sources for permission to reproduce materia in this free course: Images Course image JanPietruszka / istock / Getty Images Pus Figure 1 JackF / istock / Getty Images Pus Figure 2 Department of Heath, Reproduced under the terms of the OGL, www. nationaarchives.gov.uk/doc/open-government-icence Figure 3 shironosov / istock / Getty Images Pus Figure 5 Figure 6 Jeukendrup, A. (2014). 'A step towards personaized sports nutrition: carbohydrate intake during exercise'. Sports Medicine, 44(1). Adis Internationa Ltd Figure 7 comotion_design / istock / Getty Images Figure 8 Sigefride / istock / Getty Images Pus Figure 9 OSTILL / istock / Getty Images Pus Figure 10 Ivanko_Brnjakovic / istock / Getty Images Pus 25 of 26 Thursday 30 November 2017

26 Acknowedgements Every effort has been made to contact copyright owners. If any have been inadvertenty overooked, the pubishers wi be peased to make the necessary arrangements at the first opportunity. Don't miss out If reading this text has inspired you to earn more, you may be interested in joining the miions of peope who discover our free earning resources and quaifications by visiting The Open University 26 of 26 Thursday 30 November 2017