1. Hydration

2. Fluid – the forgotten nutrient • Humans contain 30-50 litres of water. • We lose water through sweat, urine and evaporation. • Water turn over varies between athletes. • Turnover increases during exercise and hot conditions.

3. Effects of Dehydration • Impaired Performance • By 10-20% with ~2% of body weight • Impaired Mental Function • Slowing reaction-response times • Decision making skills • Increased risk of heat cramps, exhaustion and stroke • >3% fluid loss

4. Monitoring Hydration • Urine Colour chart

5. Monitoring Hydration cont... • Hydration Monitor – Refractomer • Weight Flactuation – Before and after exercise • E.g. Athlete consumed 1L fluid during exercise but lost 1kg in weight from sweating. • Total sweat loss = 2L

6. Case Study - Mark • Mark is a central forward • Participates in a high intensity 90minute soccer training session • Pre-training weight = 75kg • Drinks 1.5L during training • Post-training weight = 73kg • To avoid dehydration and over-hydration, how much fluid should Mark consume during his next training session?

7. Case Study - Mark • Weight loss = 75-73kg = 2kg (~2L) • % weight loss = 2/75kg= 2.7% (dehydrated) • Total sweat loss = 2L weight loss + 1.5L drank during training = 3.5L • Allowable sweat loss = 2% x 75kg= 1.5L • Minimum fluid replacement = 3.5 – 1.5L = = 2L over 90 mins =~300mls per 15 minutes • Maximum fluid replacement = 3.5L = 3L over 90 minutes = 450mls per 15 minutes • Recommended Intake for Mark ~ 300-450mls/15min

8. What type of Fluids? Drink water if • Exercise <30 minutes • Low intensity exercise • If high intensity > 30-60mins and cannot tolerate sports drinks – need to take CHO and sodium in another form

9. Sports Drinks • Provide: • Carbohydrate for extra energy • Fluid for hydration • Electrolytes e.g. sodium • Choose according to requirement for: • Fluid • Carbohydrate • Fluid and carbohydrate • Electrolytes

10. Hypotonic Sports Drinks • Contain less than 6g CHO/100ml • Used when wanting to replace more fluid than CHO • Can be beneficial in hot climate with little physical activity.

11. Isotonic Sports Drinks • Contain 6-8g CHO/100ml • Used when wanting to replace fluids and CHO equally • Generally most effective choice in most situations. E.g. Team sports and individual sports.

12. Hypertonic Sports Drinks • Contain more than 8g CHO/100ml • Used when wanting to replace more CHO than fluid. • Suitable for cold climates where dehydration is not a problem but large energy expenditure. E.g. Cross country skiing, Mountaineering.

13. What affects fluid intake? • Athletes awareness of their sweat losses • Awareness of disadvantages of dehydration • Dislikes taste/sensation • Availability of fluid • Stomach comfort • Fear of weight gain • Fear of need to urinate during exercise • Lack of practice

14. Developing a Fluid Plan Pre Exercise/Event • Well hydrated before exercise • Drink fluids regularly throughout the day leading up to training/event • Have drink with meals and snacks • Fluid choice • Any fluid during the day to make up 2L and meet CHO requirements • Isotonic/Hypotonic/water in 1-2h prior to training/event

15. Developing a Fluid Plan During Exercise/Event • Fluid choice • Generally isotonic • If cannot tolerate – hypotonic/water & CHO food • 150-200mls every 10-15 minutes as a guide but really should match individual athletes sweat loss • Depends on practicalities of your sport • Practice fluid replacement plan in training

16. Developing a Fluid Plan Post Exercise/Event • Fluid choice • Generally Isotonic • If cannot tolerate then hypotonic/water plus CHO foods with salt • 1 kg body weight lost = 1L fluid loss • Aim to drink 1.5 x fluid loss over 2-4hrs after event

17. Intravenous Drips • Used to rehydrate players during competition or to aid recovery afterwards. • Athletes report faster recovery rates. • Athletes can be given a known amount of fluids and carbohydrate and can be consuming these while resting or sleeping.

18. Arguments – for and against