NMDS311 Sports Nutrition

Transcription

1 NMDS311 Sports Nutrition Session 7 Diets for Special Athletic Populations Part 1 Nutritional Medicine Department

2 Sports Nutrition Session 7 Diets for Special Athletic Populations Vegetarian diets Gluten free diets Diabetes and sports nutrition Endeavour College of Natural Health 2

3 Vegetarian Diets

4 Type Fruitarian Types of Vegetarians Comments Diet consists of raw or dried fruits, nuts, seeds, honey and vegetable oil Macrobiotic Excludes all animal foods, dairy products and eggs; uses only unprocessed, unrefined, "natural" and "organic" cereals, grains and condiments such as miso and seaweed Vegan Excludes all animal foods, dairy products and eggs. In the purest sense, excludes all animal products including honey, gelatine, silk, wool, leather and animal derived food additives (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 4

5 Types of Vegetarians Type Lacto-vegetarian Lacto-ovovegetarian "Quasi", "Pseudo", or Near-Vegetarian Comments Excludes all animal foods and eggs. Does however include milk and milk products Excludes all animal foods, however includes milk, milk products and eggs Usually excludes red meat, however includes poultry, beef extracts and fats, fish, eggs and dairy products (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 5

6 Can it Improve Performance? Currently it is unclear as to whether a vegetarian diet will improve athletic performance To date, studies have failed to examine the true benefit, if any, of a vegetarian diet on exercise performance Studies have either controlled for the inherent differences seen between vegetarian diets and nonvegetarian diets, or have used populations that are not representative of well-trained athletes (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 6

7 Can it Improve Performance? Vegetarian diets tend to be higher in nutrient-rich carbohydrates, antioxidants and phytochemicals which are conducive to enhancing muscle re-fuelling and maintaining health and well-being during periods of strenuous training However, vegetarian diets are high in fibre and lower in energy, protein, fat, vitamins B12, riboflavin, and vitamin D, calcium, iron and zinc than omnivorous diets (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 7

8 Can it improve Performance? Female vegetarians have a higher frequency of suboptimal micronutrient intakes, particularly iron, zinc, calcium and energy than male vegetarians and omnivores These characteristics often raise concern among coaches and support staff as to whether a vegetarian diet can fully support the nutritional requirements of training and competition in athletes this is where dietetic expertise comes into play (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 8

9 Can it Improve Performance? Vegetarian athletes, particularly children and adolescents, those engaged in heavy endurance training and those striving to increase muscle mass may have difficulty meeting daily energy requirements These athletes should be advised accordingly. Vegetarians have been found to consume, on average, lower protein intakes than meat eaters, although most protein intakes met population reference standards and the slightly higher sport-specific guidelines for protein of g/kg BW/day (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 9

10 Can it Improve Performance? While it was once thought that various plant proteins had to be consumed in the same meal to provide all essential amino acids, complementary meal planning is no longer considered a requirement Misinformed or unplanned athletes following a vegetarian diet may struggle to meet daily protein intake goals and incorporate adequate protein at strategic times throughout the day (i.e. during the postexercise period) to optimise the response from daily training (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 10

11 Can it Improve Performance? Furthermore, vegetarian athletes travelling for extended periods that rely heavily on eating out may also be at risk as many eating establishments do not typically incorporate protein rich plant-based alternatives (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 11

12 Protein Risk of Deficiencies in Vegetarian Athletes Iron Calcium B12 Zinc (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 12

13 Protein Vegetable or plant proteins may be limiting in one or more essential amino acids (the building blocks of protein), so food sources need to be combined in such a way to ensure all amino acids are consumed This is a particular issue for athletes who avoid all animal proteins such as milk and eggs (i.e. vegans) There is no requirement to include complementary proteins at each meal as long as a variety of protein sources are included throughout the day (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 13

14 Protein Combining different types of plant foods allows low levels of amino acids in one food to be complemented by high levels of amino acids in the other (i.e. legumes and grains, or legumes and nuts/seeds) Furthermore, as plant proteins are less well digested than animal proteins, vegetarian athletes are advised to consume approximately 10% more protein than current athlete protein recommendations This is of particular concern for vegetarians with relatively low energy budgets (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 14

15 Iron Iron is arguably the nutrient most at risk in a vegetarian diet Meat provides a source of haeme iron, which is absorbed more effectively than the non-haeme iron from grains and vegetables Iron status can be enhanced by consuming foods rich in vitamin C and by avoiding iron inhibitors such as the tannins in tea and, to a lesser extent, the caffeine in coffee and cola drinks (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 15

16 Calcium Obtaining sufficient calcium can be a challenge for those vegetarians not consuming dairy foods Poor calcium intake can increase the risk of low bone density, thereby increasing the risk of fracture Calcium-fortified soymilks are an excellent alternative to dairy products (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 16

17 Vitamin B12 Vegan diets tend to lack vitamin B12, so supplemental B12 from a fortified soymilk or dietary supplement is recommended Vegetarian athletes should discuss with their sports physician whether it is necessary for them to take a B12 supplement or infusion (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 17

18 Zinc Inadequate zinc intake may compromise immune function and the healing of wounds Meat, chicken and fish are the major dietary sources of zinc, and thus the vegetarian athlete needs to consume alternatives such as whole grains, nuts and seeds, and legumes Nutritional deficiencies of protein, iron, calcium, or vitamin B12 may adversely affect performance by reducing energy levels, delaying recovery and inhibiting muscle repair and growth (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 18

19 Gluten free diets

20 Gluten Free Diets Are They Better for Non-Coeliac Athletes? Gluten-free diets (GFD) are a clinical necessity for 5-10% of the general population for health purposes including coeliac disease, wheat allergy and non-coeliac gluten sensitivity However, general population market reports indicate that the adoption of a GFD has far exceeded the requirement for clinical populations, with GFD uptake exploding amongst non-coeliac athletic populations as well (Lis D et al ) Endeavour College of Natural Health 20

21 Gluten Free Diets Are They Better for Non-Coeliac Athletes? Correspondingly, our recently published questionnairebased study, which investigated the frequency, perceptions and beliefs surrounding GFD, found that in 942 non-coeliac athletes over 40% reported following a GFD at least 50% of the time. Startlingly, this group of non-coeliac athletes mostly relied on self-diagnosis of a gluten-related disorder and subsequent self-treatment with a GFD. (Lis D et al. 2015) Endeavour College of Natural Health 21

22 Gluten Free Diets Are They Better for Non-Coeliac Athletes? General population gluten avoidance has become prevalent due to a belief that a GFD is healthier, or owing to self -diagnosed gluten-related gastrointestinal (GI) disorders Non-coeliac athlete populations adopt a GFD in the belief that it is not only healthier and augments weight loss, but will also decrease GI distress and systemic inflammation and improve psychological well-being and athletic performance (Lis D et al. 2015) Endeavour College of Natural Health 22

23 Gluten Free Diets Are They Better for Non-Coeliac Athletes? Thirteen competitive endurance cyclists (8 males, 5 females) with no positive clinical screening for coeliac disease or history of Irritable Bowel Syndrome were allocated to a seven day gluten-containing diet (GCD) or gluten free diet (GFD) separated by a 10-day washout in a controlled randomized double-blind, cross-over study Cyclists ate a GFD alongside either gluten-containing or gluten-free food bars (16g wheat gluten per day) while habitual training and nutrition behaviors were controlled (Lis D. et al, 2015) Endeavour College of Natural Health 23

24 Gluten Free Diets Are They Better for Non-Coeliac Athletes? During each diet, cyclists completed the Daily Analysis of Life Demand for Athletes (DALDA) and GI questionnaires (post-exercise and daily) On day seven cyclist completed a submaximal steadystate (SS) 45 minute ride at 70% peak power followed by a 15 minute time-trial (TT) (Lis D et al. 2015) Endeavour College of Natural Health 24

25 Gluten Free Diets Are They Better for Non-Coeliac Athletes? Blood samples were taken pre-exercise, post SS and post TT to determine intestinal fatty acid binding protein (IFABP) and inflammatory markers. Mixed effect logistic regression was used to analyze data RESULTS: TT performance was not significantly different (P = 0.37) between the GCD and GFD. GI symptoms during exercise, daily, and DALDA responses were similar for each diet. There were no significant differences in IFABP or cytokine responses. (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 25

26 Gluten Free Diets Are They Better for Non-Coeliac Athletes? o CONCLUSION: A short-term GFD had no overall effect on performance, GI symptoms, well-being, and a select indicator of intestinal injury or inflammatory markers in non-coeliac endurance athletes. (AIS Sports Nutrition, 2009) Endeavour College of Natural Health 26

27 Endeavour College of Natural Health 27

28 Diabetes and Sports Nutrition

29 How does exercise affect diabetes management o Factors such as muscle contraction, increased blood flow and increased body temperature cause the body to more responsive or 'sensitive' to insulin during exercise. o Therefore, in people who do not have diabetes, insulin levels decrease during exercise. o People with Type 1 diabetes usually need to adjust their insulin dose to account for a reduced requirement for insulin during exercise. Regular monitoring of blood glucose levels and trial and error (Burke & Deakin, 2015) Endeavour College of Natural Health 29

30 How does exercise affect diabetes management o Regular monitoring of blood glucose levels and trial and error is needed to understand and manage each individual's response to exercise (under the care of a diabetes specialist). o Intensity and duration of exercise Pre-exercise insulin dose generally needs to be reduced when exercise extends beyond 30 minutes. The level of reduction varies for each individual but, in general, the longer the period of exercise, the greater the reduction required. (Burke & Deakin, 2015) Endeavour College of Natural Health 30

31 How does exercise affect diabetes management o Adjustments to insulin should be made with the guidance of your diabetes specialist, especially in the early stages of management. o Degree of metabolic control before exercise It is easier to manage and predict the body's response to exercise when metabolic control is good. It is dangerous to commence exercise when blood glucose levels are high and ketones are present in the urine. (Burke & Deakin, 2015) Endeavour College of Natural Health 31

32 How does exercise affect diabetes management o Type and dose of insulin injected before exercise It is common practice to use a mixture of short and long lasting insulin to manage diabetes. It is necessary to predict the peak period of insulin activity to avoid excessive levels of insulin injection during exercise. o Site of insulin injection Insulin absorption is increased in exercising muscles. The abdomen is usually the preferred site for insulin injection prior to exercise. (Burke & Deakin, 2015) Endeavour College of Natural Health 32

33 How does exercise affect diabetes management o Timing of previous meal Insulin requirements are influenced by the amount and type of food consumed. (Burke & Deakin, 2015) Endeavour College of Natural Health 33

34 Eating Before Training and Competition o As for all athletes, a carbohydrate-based pre-exercise meal 1-3 hours before exercise is recommended. o It is important for people with Type 1 diabetes to ensure blood glucose levels are at an appropriate level before commencing exercise - ideally between 4-8 mmol/l. o Exercising with high blood glucose levels disrupts normal metabolic control and will elevate levels even further. (Burke & Deakin, 2015) Endeavour College of Natural Health 34

35 Eating Before Training and Competition o Apart from being dangerous, this will result in poor performance. In general, exercise should be postponed if blood glucose levels are above mmol/l, especially if ketones are present in the urine. o Being attune to the symptoms of hypo- and hyperglycaemia and regular monitoring is necessary in these situations. (Burke & Deakin, 2015) Endeavour College of Natural Health 35

36 Eating During Training and Competition o Research suggests g of carbohydrate per hour will aid performance. o Usually it is not necessary to have extra insulin if you eat during exercise. o Choices such as sports drinks that provide fluid and carbohydrate are a convenient option for most exercise situations. o Other options such as carbohydrate gels, fruit and sports bars may also be tolerated. (Burke & Deakin, 2015) Endeavour College of Natural Health 36

37 Eating During Training and Competition o If additional carbohydrate is required during exercise, it is better to consume small amounts frequently rather than leave it until the last minute. o TRY ANY NEW STRATEGIES DURING TRAINING SESSIONS WHEN IT IS EASIER TO MONITOR THE EFFECTS ON BLOOD GLUCOSE CONTROL (Burke & Deakin, 2015) Endeavour College of Natural Health 37

38 Eating After Training and Competition o The increased insulin sensitivity caused by exercise lasts for several hours after exercise. o Therefore the risk of hypoglycaemia persists for some time. o Delayed hypoglycaemia can occur 4-48 hours after exercise. o Preventing delayed hypoglycaemia involves making sure you (Burke & Deakin, 2015) Endeavour College of Natural Health 38

39 Eating After Training and Competition o Preventing delayed hypoglycaemia involves making sure you consume sufficient carbohydrate before, during and after exercise. o It may also be necessary to reduce the next insulin dose after exercise. It is helpful to monitor your blood glucose levels frequently after exercise. o Inconveniently, delayed hypoglycaemia often occurs during the night. If this occurs regularly, it can exacerbate fatigue in athletes. (Burke & Deakin, 2015) Endeavour College of Natural Health 39

40 Eating After Training and Competition o Waking up feeling very tired and groggy in the morning may indicate you have experienced a 'hypo' during the night. o This is a sign that you need to increase blood glucose monitoring after similar exercise sessions in the future. o Alcohol inhibits the release of glucose from the liver therefore increases the risk of hypoglycaemia. Consuming excessive alcohol also impairs the ability to recognise the symptoms of hypoglycaemia. (Burke & Deakin, 2015) Endeavour College of Natural Health 40

41 Controlling Blood Glucose Levels During Competition o Excitement and nerves surrounding competition are almost inevitable. o A side effect of excitement is the release of hormones such as adrenalin and cortisol. These hormones stimulate the release of glucose from the liver and reduce the effectiveness of insulin. (Burke & Deakin, 2015) Endeavour College of Natural Health 41

42 Controlling Blood Glucose Levels During Competition o This can cause fluctuating blood glucose levels. Ways to avoid or cope with this include: Emulate your race/competition preparation in training (including physical preparation and recovery, and nutrition strategies) Try and practice some relaxation techniques (correct breathing techniques, muscle relaxation techniques, music, or talk to a sports psychologist) Write your routine down on paper before the event so you don't forget your routine amongst all the excitement. (Burke & Deakin, 2015) Endeavour College of Natural Health 42

43 References o AIS Sports Nutrition, last updated March Australian Sports Commission. 20Nutrition%20for%20Vegetarian%20Eating.pdf o Burke, L & Deakin, V 2015, Clinical sports nutrition, 5 th Ed, McGraw Hill, Sydney. o Lis, D, Stellingwerff, T, Kitic, C.M, Ahuja, K, Fell, J,. (2015) No Effects of a Short-Term Gluten-free Diet on Performance in Noncoeliac Athletes.Med Sci Sports Exerc. Dec; 47(12): doi: /MSS Endeavour College of Natural Health 43

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