Hayes, Mark

Maxwell, Neil

Webborn, Nick

English

1. Prepare and acclimatise for heat at Tokyo 20202. Being heat illness aware, and recognise the signs and symptoms3. Staying hydrated at the Games4. Keeping cool while living and competing in the heat<br/

University of Brighton Research Portal

HOW TO STAY HYDRATED AT THE TOKYO PARALYMPIC GAMES?D R  N E I L  M A X W E L L  &  P R O F E S S O R  N I C K  W E B B O R NBuda Mendes/Getty Images2DEHYDRATION IMPAIRS PERFORMANCE - FACTBy the time you are thirsty, you are already dehydrated by ~ 2% of body weightDehydration can reduce:• Aerobic performance• Strength• Power• Concentration• Decision making3PREPARING YOUR HYDRATION STRATEGY FOR THE HEAT AT TOKYO 20201. The Para athlete will encounter a unique challenge in Tokyo that will impact their thermoregulation and hydration2. As you acclimatise to the Tokyo heat, your sweat rate will increase to control your temperature – but you also need to replace it – extra fluid needed3. Simple measures exist to allow athletes to measure their own hydration status4. All athletes should have a practiced individual hydration strategy in place prior to Tokyo4HYDRATION TERMINOLOGYGreenleaf, Med SciSports Exercise 1992 (6), 645-656.Euhydration – “normal” body water content within body’s homeostatic rangeDehydration – the process of dynamic loss of body water – e.g., the transition from euhydration to hypohydrationHypohydration – state of body water deficitRehydration – the process of a dynamic gain of body water (via fluid intake) – e.g., the transition from hypohydration to euhydrationOver- or Hyperhydration – state of body water excess5WHY SHOULD I STAY HYDRATED?2. Drinking fluids can cool you down and help reduce a heat-related illness 3. For some Para athletes, different cooling methods may be needed due to reduced sweating and impaired thermoregulation4. Dehydration can lead to athletes making poor decisions in competition – not just physical effects1. Water makes up 50-70% of body mass5. Being dehydrated can impair performance in some sports 6HOW CAN I CHECK IF I  AM HYDRATED?• Athletes can monitor: urine colour/frequency/volume,  thirst sensation • Sport scientists might measure your urine osmolality or specific gravity Urine Frequency or VolumeYou can also weigh yourself first thing in the morning to check if you are dehydrated based on your ‘typical’ weightUse two or more indicators of hydration status7ARE YOU DEHYDRATED?LikelyLikelyLikelyVery LikelyAm I Thirsty?Yes / NoIs my urine dark yellow?Yes / NoIs my body mass >1% lower than normalYes / NoAssess first thing in the morning (before breakfast)8CALCULATING YOUR OWN HYDRATION STATUSExample: Athlete X’s body mass decreased from 65.3 kg to 63.8, so a D body mass  = - 2.2 kgHydration Status = [(∆ body mass) / baseline body mass]*100= (-1.5 / 65.3) * 100= -2.3% change in body massEquipment NeededBody weight scales to 0.10 kg or better and towelHydration status = % change in nude body massCalculation: [(∆ body mass) / baseline body mass]*1009CAN I WORK OUT MY SWEAT RATE DURING EXERCISE TO KNOW MUCH FLUID TO TAKE ON AFTERWARDS?Weight before exercise (minimum clothes)Weight after exercise (towel dry)Duration of exercise (in hours)Acute body mass change to estimate hydration status is appropriate for most individualand team sports < 3 h of exerciseSweat rate (Litres per hour) =Weight before exercise - Weight after exerciseDuration of exercise (in hours)10WHAT IS A NORMAL SWEAT RATE? Meann=1303Para-athletes can determine their own sweat rate when competing in the heat to help develop an individualized fluid strategy.Some para-athletes (amputees, spinal cord injured, with multiple sclerosis) will not perceive heat as much to drink and/or sweat as much as able-bodied athletes.11HOW TO CALCULATE FLUID TO DRINK FROM WEIGHT LOSS?Weight before Weight afterWeight lostWeight lost_ =Amount to drinkWeight before =xWEIGHT LOST AMOUNT TO DRINK0.2 kg 300 ml0.5 kg 750 ml1.0 kg 1.5 L1.5 kg 2.25 L2.0 kg 3 LRehydration required based on weight lost It is easy to work out how much you need to drink after exercise, you just need to weigh yourself before and after your activity. It is recommended that you drink 1.5 times the amount of sweat that is lost, assuming that 1kg equals 1L of waterORuse the table to find the amount you need to drink 12SHOULD I PLAN DRINKING OR DRINK TO THIRST?Planned DrinkingLonger duration activities > 90 minParticularly in the heatHigh intensityHigh sweat ratesWhen performance is a concernWhen carbohydrate intake of 1 g/minDrink to ThirstShort duration activities < 60 to 90 minCooler conditionsLower intensityKenefick (2018)Some athletes with a spinal cord injury may deliberately reduce fluid intake to avoid repeated visits to the bathroom, but this increase dehydration, resulting in fatigue, reduced performance and likelihood of urinary tract infections13WHAT ARE MY FLUID NEEDS BEFORE AND AFTER EXERCISE?Guiding principles for para-athletes• Individualized hydration plan based on the athlete’s expected sweat rates• Opportunity to consume fluids during their event?• Gastrointestinal tolerance of fluids• Access to fluids• Ease of access to bathroom during exerciseFor para-athletes with high sweat rates, or who consistently show > 2% dehydration during exercise, drinking fluid prior to exercise and drinking regularly during the session is likely to be more effective than waiting until you are thirstyTraining sessions can be useful for trialling timing, volume and type of drink the para-athlete needs 14DO I NEED SODIUM (SALT) IN MY DRINK?Sodium stimulates thirst – which leads to increased fluid intakeSodium helps maintain proper fluid and electrolyte balance in the bodySodium supports how well your heart functions during exercise through better maintenance of blood volume Sodium stimulates your kidneys towards better fluid retention Consume sodium with fluids if exercise is >2 h, in hot weather and/or if sweat electrolyte losses are known to be very high15WHAT FOODS CAN HELP ME STAY HYDRATED?Remember to always drink with your meals as the electrolytes will assist with fluid retentionConsuming a small salted snack [e.g. pretzels and/or fluids containing sodium (20–50 mmol/l or 460–1150 mg/l) or glycerol (1.2–1.4 g/kg fat-free mass (FFM) with ∼ 25 ml/kg FFM fluid)] before exercise may help stimulate thirst and retention of fluids16WHAT ARE 7 GOLDEN RULES OF GOOD HYDRATION PRACTICE FOR ATHLETES?1. Athletes should carry  fluid  with them at all times - with your own water bottle being distinguishable from other athletes2. Ice slurries can reduce sweat rate and slow heat loss but can be effective in humid conditions like Tokyo3. Too much fluid too quickly can cause gut discomfort or a need for frequent visits to the toilet. Keep a steady pace of drinking that you have practiced.4. Hand Cooling, while effective at reducing heat, can reduce function and grip, or be difficult for glove wearers. Focus on cooling non-active body parts. 5. Sports drinks have energy in them and too much carbohydrate  can influence  the body’s ability to maintain thermal balance in hot environments6. Water alone is not ideal for hydrating – so some carbohydrate and electrolytes  in fluid helps the uptake of the fluid and replenishment of energy stores7. Know your hydration plan based on your sport, level of impairment and sweat rate – then practice it alongside cooling strategies.17Barnes, K.A., Anderson, M.L., Stofan, J.R., Dalrymple, K.J., Reimel, A.J., Roberts, T.J., Randell, R.K., Ungaro,C.T., Baker, L.B. (2019). Normative data for sweating rate, sweat sodium concentration, and sweat sodium lossin athletes: An update and analysis by sport., J Sport Sci, 37(20), 2356-2366.Cheung, S.S. and Ainslie, P.N. (2022). Hydration strategies for exercise (Chpt 4), In Advanced EnvironmentalExercise Physiology (2nd edition), Human Kinetics, Champaign, IL.Kenefick, R.W. (2018). Fluid intake strategies for optimal hydration and performance: planned drinking vs.drinking to thirst. Sport Science Exchange, 29 (182), 1-6.Griggs, K.E., Stephenson, B.T., Prince, M.J. and Goosey-Tolfrey, V.L. (2020). Heat-related issues and practicalapplications for Paralympic athletes at Tokyo 2020, Temperature, 7, Special Issue 1 of 2.Prichett, K., Broad, E., Scarmella, J. and Baumann, S. (2020). Hydration and cooling strategies for Paralympicathletes, Current Nutrition Reports, 9(3), 137-146.RESOURCES THAT SUPPORTED THIS PRESENTATIONPhoto ©: OISTHANK YOU

International Paralympic Committee Beat The Heat Athlete Advice Sheets

https://cris.brighton.ac.uk/ws/files/25409417/How_to_Stay_Hydrated_at_the_Tokyo_Paralympic_Games.pdf

International Paralympic Committee Beat The Heat Athlete Advice Sheets

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