Fluid for Sport

1. Fluid for Sport Lucozade Sport Education Programme Eimear Forbes Sports Dietitian (BSc. Hum Nut & Diet, Pg Cert Sports and Exercise Nutrition, MINDI, ISAK level 1 Anthropometrist) ,)

2. Objectives Outline effects of dehydration on health & performance Highlight issues around hydration in endurance sports Discuss what fluids to use & when (pre, during and post exercise fluid choices) Provide a brief introduction to food for sport In workshops we will look at.. Calculating fluid requirements & replacement Monitoring hydration status

3. Running-effects on the body

4. For a person undertaking regular exercise, any fluid deficit that is incurred during one exercise session can potentially compromise the next session if adequate fluid replacement does not occur. Shirreffs SM, Armstrong LE, Cheuvront SN. 2005. Food nutrition and sports performance II

5. Fatigue During Prolonged Exercise Substrate (glycogen) depletion Temperature regulation/fluid balance

6. Water becomes the most important performance-enhancing nutrient when exercise and heat stress are combined. In General dehydration is not good for achieving optimal athletic performance while exercising. Without fluid intake blood volume will drop, sweat rates will drop and body heat will rise. It is very difficult to consume enough fluids to match those lost during exercise Most athletes and coaches are aware that a reduction in the body’s water content impairs exercise performance. What happens? Hydration status is determined by the balance of intake versus output Water accounts for 50-70% of the body mass in most people. Females have less than males (they are lighter and have a higher proportion of body fat). An important route of water and electrolyte loss is through sweating. Water/ Fluids

7. What are the functions of water Maintain life (we can only survive a few days without it) Gives structure and form to the body Red blood cells carry oxygen in the plasma Transports nutrients (glucose, electrolytes, iron) Transports metabolic waste products and CO2 Transports hormones to target sites Lubricates joints Protects organs Regulate body temperature by absorbing heat with only small changes in temperature and dissipating heat Influences blood pressure and cardiovascular function

8. Why is water important? Fluid is essential to maintain hydration on a daily basis Body is ~ 55-65% water Muscles made up ~ 70% water Each g of Glycogen stores 3g of water Water has important functions in the body Circulation of nutrients Removal of waste products Keep your body temperature stable Protects organs (including brain – note combat sports) Influences blood pressure and cardiovascular function

9. What is Dehydration ? Dehydration occurs when water output exceeds water intake producing a deficit in body water Fluid loss arises from.. Sweating Urination Breathing & faecal losses smaller Sweat loss will depend on several factors Considerable variability exists between athletes of the same weight & sports

10. Most athletes and coaches are aware that a reduction in the body’s water content impairs exercise performance Inadequate fluid during training and competition leads to: ↓blood volume, ↓sweat rates  ↑body heat & underperformace It is often difficult to consume enough fluids to match those lost during exercise In combat sports dehydration is often used prior to ‘Making Weight’ (>2% not recommended) Some degree of dehydration may be present at competition but good post weigh-in recovery plans will minimize this What do we need to consider?

11. Sweating Heat generated in exercise is transferred from the body core to the skin, where it vaporises the liquid sweat Evaporation of sweat usually accounts for 80% of heat loss during exercise Sweat rates of up to 1.5L per hour during moderate intensity exercise are not uncommon

12. Increased core temp sensed by brain Brain switches on sweat mechanisms Hot blood pumped to cooler skin Heat transferred into atmosphere Sweating is effective in limiting the rise in body temperature during exercise Sweat rates of 1.5L/hr in moderate intensity exercise are common

13. What Can Happen Dehydration If not replacing fluid Not enough water for sweating Core temperature rises In hot humid conditions Sweat doesn’t evaporate Body temperature increases

14. What Can Go Wrong Body temperature increases Impaired performance Heat stress Circulatory collapse Heat stroke/ hyperthermia

15. Adverse Effects of Dehydration

16. How to Recognise Dehydration Changes in body weight (pre and post training) Allows coaches and medical staff to see what athletes can usually lose in a training session or competition. Hydration plans can be individualised based on the results. Urine test Colour is a practical way that athletes can use. Specific gravity of urine measures the concentration urine. The more concentrated the more dehydrated an athlete is. A good field test for athletes to determine if they are prepared for training or competition. Results prior to training or competition allows you to make interventions to improve hydration status before you start. For every 1 kg (2.2 lbs) body weight lost in a training sesion, 1.5 litres of fluid must be replaced

17. Fluid requirements Athletes must be fully hydrated before they train or compete because the body cannot adapt to dehydration. Daily fluid requirements range between 2 – 4 L Will vary to each individual and depends on.. weight, age, sex, sweat rate, environment, intensity & duration of activity 35mls per kg / BW adults + losses 50mls per kg / BW <18 years + losses

18. Squash Player example Training session ~ 1 hour training / match Weighs 72kg before training & 71kg after training 500mls drinks bottle before & 200mls remaining = drank 300ml % Dehydration = weight difference x 100 = 1 x 100 = 1.4% weight before exercise 72 Total fluid loss = weight difference + fluids consumed = 1kg (1000ml) + 300ml = 1300mls Fluid required = 1300mls x 1.5* = 1950mls – 300mls = 1650mls *for every 1 kg body weight loss replace with 1.5l of fluids (150% Rule)

19. Stop for Task !

20. Task 2 – group work Divide into groups: 6x 6 Calculate in the 2 case examples TOTALS FLUIDS LOST Fluid replacement required

21. Using a Pee Chart Urine colour is a practical way that athletes can use to assess adequate hydration Your target is to aim for the same colour as 1,2 or 3 The more concentrated the urine the more dehydrated an athlete is. Specific Gravity of urine can be measured using a refractometer for more serious athletes Monitoring hydration – Urine test

22. Monitoring Hydration Status

23. Purpose of Drinking Supply substrate (carbohydrate) Prevent dehydration Post-exercise dehydration Electrolyte replacement

24. You can easily become dehydrated over successive days of training & competition if you fail to re-hydrate fully between workouts Check hydration status using Pee Charts Watch out for.. Sluggishness General sense of fatigue Headaches Loss of appetite Feeling excessively hot Light headedness Nausea How to Recognise Dehydration

25. Importance of Hydration Thirst is not a good indicator Different athletes will have different fluid requirements: For every 1kg lost in weight with exercise, must replace by 1.5 Litre fluid. Indicates amount fluid needed in activity On average 150- 300mls fluid every 15 mins should combat dehydration Need to have fluid with electrolytes to avoid hyponatraemia

26. Avoiding Dehydration General Guidelines Accustom your body to increased fluid intake during training and competition Practise all new strategies in training or minor events Wear appropriate clothing that allows heat transfer

27. Avoiding Dehydration Pre-Training/Competing Begin exercise when fully hydrated Drink sports drink or water prior to exercising until your urine is clear Allow some time to get rid of excess urine In sports lasting < 30 mins water is still the recommended fluid replacement during exercise (ACSM 2007)

28. Avoiding Dehydration During Training/Competition 150ml / 15mins endurance sport, 30-60g CHO per hour Therefore if no food taken when exercising use 6-8% CHO drink ( ie isotonic drink) to provide fuel and fluid Don’t use thirst as an indicator of need for fluid

29. Avoiding DehydrationAfter Exercising Drink 1.5 L for every 1 kg weight lost Choose a drink designed to rehydrate most effectively The drink should contain: Relatively high concentration of electrolytes (especially sodium around 50 mMol/l) to maximize fluid retention 6-8% carbohydrate for optimal fluid/energy recovery 2-3% carbohydrate for optimal rehydration

30. General tips for Fluid Replacement Drink before you get thirsty Pre-hydrate – drink before exercise Non-carbonated drinks – are tolerated better Caffeine free – drinks high in caffeine can cause dehydration <6-8% carbohydrate solution for fast absorption Temperature: 8-12oC – cooler drinks leave stomach sooner Palatability. Pick a drink you like Individual variation-practice prior to competition In Sports lasting < 30mins water is still a recommended fluid to use for hydration during & after activity

31. Sports Drink vs. Water

32. Restrict isotonic sports drinks if you are: On special diets (e.g. carbohydrate restriction) Attempting to lose weight Making weight for a specific sport

33. Dental Health – remember your teeth! Sports drinks are acidic which can breakdown tooth enamel They also contain carbohydrate which can increase dental caries • Brush and floss your teeth regularly • Ensure regular dental check-ups • Chew sugar free gum • Use a squeeze bottle or drink from a straw. • Drinks should be slightly chilled. • Rinse mouth out with water after eating and drinking.

35. Home Made Sports Drinks Using Fruit Juice 500mls fruit juice 500mls water (cooled boiled water) 1g salt Using diluted squashed 200ml fruit squash 800ml water (cooled boiled water) 1g salt Using glucose / carbohydrate powders 40-80g sugar/glucose powder 1000mls water (cooled boiled water) 1g salt

36. Practice Makes Perfect…… Practice hydration and food techniques in training Nothing new on day of event Fluid and carbohydrate pre, during and post event are vital for optimum performance

37. If you want to avoid dehydration and enhance performance… consume plenty of fluids before, during and after exercise.

38. Thank You For more information, log on to these websites: Irish Nutrition and Dietetic Institute (www.indi.ie) – find a dietitian, sports nutrition info Coaching Ireland website(http://www.coachingireland.com) Lucozade Sport Science and Nutrition centre(http://www.lucozadesport.com/lucozade/ wwwroot/index.html)

39. Summary Table: Nutrition and Hydration Principles in Endurance Sports This applies to event of approx 1hr or more, plans must be individualised to each person and sport

40. What are the key nutritional issues for performance? Adequate appropriate fuel or energy (calories) Adequate fluid Timing especially for recovery Good balance Habit Preferences

41. Adequate Energy There are four components in food and drinks that are capable of producing energy Fat (essential nutrient, little risk of depleting stores) Alcohol (contributes to increase in fat stores, negative impact on recovery and hydration strategies) Protein (growth and repair, significant structural part of muscle) Carbohydrates (sugars and starches) (most important nutrient for exercising muscle, stores last max 70mins in exercise) The exercise intensity will determine the type of fuel that is used. Vitamins and Minerals essential

42. Energy Stores: Where Is Fuel Stored? In the blood as glucose In the liver and muscles as glycogen In adipose tissue as fat (just below the skin) Muscle will be broken down to access protein if it is used as an energy source (if carbohydrates are not present).

43. Energy Stores: Where Is Fuel Stored?

44. If don’t fuel well…Consequences? Early Fatigue Poor Recovery Lose weight Difficulty building muscle …………….Impaired Performance

45. Nutritional Requirements in Sport

46. Carbohydrates Stored in body as glycogen in liver and muscle = limited stores Inadequate intake = incomplete glycogen stores Effects: early fatigue, poor recovery, weight loss, under performance

47. Increasing Carbohydrate Stores Carbohydrate at each meal: cereal, bread, pasta, rice, potatoes, fruit Fruit to breakfast cereal, thicker slices bread, potato in soups / salads Carbohydrate snacks: Fruit, low fat yoghurt, smoothie, cereal bar, dried fruit Use sparingly the less nutritious sources of carbs: fizzy drinks, desserts, sweets, biscuits, gels

48. Carbohydrate Sources

49. What about Protein??? Despite the research available on carbohydrates athletes often believe that protein is the most important nutrient to achieve athletic success. Majority athletes require increased protein intake Can be met from the increased food intake as result of overall extra energy and carbohydrate requirement Carbohydrate consumed with small amount protein (approx 11g) post exercise will promote recovery and regeneration processes

50. On the day- pre match When to eat: Do Not skip breakfast Nerves may slow down digestion Aim for 2-4 hours pre event meal ( 1-2 hrs pre event snack) Low GI, low fat, low protein Low or moderate in fibre (high fibre may cause abdominal discomfort) Not too spicy Enjoyable and familiar foods