Physically Speaking: Play it cool

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Playing WTA tournaments means you’ll encounter very hot and/or humid environmental conditions. Training and competing in these extreme weather conditions is a challenge to all players’ thermoregulatory (temperature control) systems. To perform at your best, it is important to prepare smartly, acclimatize, and implement proper pre, during, and post tennis hydration and cooling practices. Proper planning and preparation will equip you to play energetically through to the final point and reduce your overall risk of developing exertional heat-related illness.

RISKY BUSINESS

When training and competing in hot and/or humid conditions, the risk for early onset of fatigue and heat-related illness is directly increased by the factors below:

Inadequate hydration
High sweat volume
Excessive sweat salt loss
Poor heat acclimatization
Dehydration due to travel
Overworking/undue fatigue
Prolonged sun exposure
Recent illness/infection
Poor nutrition

Combining any of these risk factors with strenuous physical activity such as tennis in hot and humid conditions can quickly lead to EXERTIONAL HEAT ILLNESS and potentially a medical emergency.

Exertional heat illness signs and symptoms can vary from mild to severe. Some exertional heat illnesses are minor, when the indications and causes can be easily treated and promptly resolved by a healthcare provider. Minor heat illnesses include:

Exertional muscle cramps – Mild to intense muscle spasms in the legs, arms and trunk triggered by muscle overload, muscle fatigue and/or extensive body water and/or sodium deficits.
Heat syncope – Fainting or near-fainting caused by extended exposure to heat, dehydration, and pooling of blood in the legs after exercise; characterized by dizziness, tunnel vision, weakness, and low blood pressure and heart rate.

Exertional heat illness is considered major if the signs and symptoms described above progress to OR indicate a state which requires significant/extensive and immediate medical intervention. Major heat illnesses include:

Heat exhaustion – Indicated by a normal or high body temperature (<40°C/104°F), heavy sweating, (or absence of sweating), significant dehydration, energy depletion, excessive fatigue, weakness, headache, nausea, rapid breathing, low blood pressure, weak and rapid pulse, and collapse/fainting.
Exertional heat stroke – This is a medical emergency characterized by confusion, disorientation, impaired judgment, and possibly more severe central nervous system abnormalities (i.e. convulsions or coma), along with loss of body temperature control (>40°C/104°F) and circulatory failure. This can lead to loss of consciousness, multiple organ (i.e. brain, kidneys, liver, spleen) failure, and tissue (including muscle) damage and death.

Speak to your primary health care provider about proper match preparation and hydration testing, including sweat volume and composition and/or thermal assessment. These tests help to determine the risk for heat-related illnesses and provide individual guidelines for prevention and management.

PREVENTION IS KEY, PLAN AHEAD

Be smart and plan your schedule according to the Sport Sciences and Medicine Department’s guidelines. These recommendations are found within the program, ScheduleZone©, which is a planning tool (accessible via PlayerZone©). The most important factor is to allow adequate time for your body to adapt to hotter environments, so that you are more likely to safely tolerate the new environmental challenges - this is termed, HEAT ACCLIMATIZATION. The time it takes for complete heat acclimatization depends on the difference between environmental conditions in your recent/current location and the new site. It could take 7 to 14 days of progressive exposure to the new conditions (exercising in the heat) for full acclimatization; but you will start to feel acclimatized after 4-5 days.

HOW SHOULD YOU ACCLIMATIZE TO THE NEW ENVIRONMENT?

When planning your schedule, it is ideal to include 7 up to 14 days of progressive heat acclimatization.
Mimic the climate of your next tournament destination by training in an environment with similar heat and humidity weather conditions. If you’re unable to train to a hot environment, prepare by exercising in extra clothing (cotton sweats) or in a warm room, while each day progressively increasing the indoor temperatures.
Upon arriving in a hot environment, train at the coolest part of the day. Each day progressively move practice times up one hour, until you are training in the hottest part of the day. Gradually increase outdoor activity duration and intensity, with the goal of completing a 90 to 100-minute vigorous training session in the heat without experiencing symptoms of heat illness.
Too much and too frequent exposure to extreme heat conditions during practices or early competition rounds may interfere with your body’s ability to recover. Implement recovery strategies to cool the body after heat exposure.

HOW CAN YOU STAY COOL?

Exercise-induced increases in body core temperature are normal. However, when these become too high, the risk of major heat-related illness increases which will negatively impact performance and well-being. Using cooling techniques helps to slow on-court increases in body core temperature by increasing heat storage capacity (pre-cooling), reducing thermal stress during exercise (per-cooling) and accelerating recovery following intense exercise (post-cooling).

PRE-COOLING is the act of lowering body core temperature prior to competing in hot and humid conditions. In theory, starting competition with a cooler body enables you to increase your heat storage and perform more work before you reach a performance-limiting and potentially unsafe body core temperature which limits performance. Effective pre-cooling methods include:

Stay out of the heat – prepare in an air-conditioned area, warm-up in the shade
30-40 minutes prior to the match, immerse in the ice bath for 5 minutes
20-30 minutes prior to the match, take a cold shower lasting 5 to 10 minutes in duration
1 hour prior to the match, apply an ice vest and/or ice blanket/towels to your torso for 15 minutes
30 minutes prior to the match, drink 8-20 ounces of sport drink slushy
Preparation - apply sunscreen, wear a hat/visor, and compete in light-colored, breathable clothing

PER-COOLING is the act of reducing thermal strain (minimizing the rise in body temperature) during play/practice.

Use an ice vest, ice towel, ice packs, ice sausages on change of ends and between set breaks
Consume cold water and sport drink regularly
Use an on-court umbrella and fan during change ends and between set breaks

POST-COOLING is the act of more deliberately lowering your body core temperature following a competition or practice session, to enhance recovery and potentially reduce exercise-induced muscle soreness.

Continuous cold emersion in ice bath or cold shower: 5-10 minutes
Ice flush: 10 minutes

Every athlete should adopt individual pre-cooling and post-cooling strategies. Begin by implementing these strategies in practice, before introducing them into competition.

BEAT THE HEAT by implementing the following nutrition, hydration, and cooling recommendations:

PRE-MATCH:

Consume 8-20oz sport drink slushy 30 mins prior to play
1-hour prior, hydrate with 12-16 ounces of water/sport drink
Add salt to your sport drinks, 600mg (1/4 tsp) salt per 20oz
2-4 hours prior to play, eat high carb, moderate protein, low fat
30-60 minutes prior to play, consume a high-carb snack (gels, chews, chomps, fruit
Check your urine color or specific gravity to ensure adequate hydration

DURING MATCH:

Hydrate with up to 6-8 gulps every change of ends
1-1.5L per hour (50:50 ratio sport drink to water)
30-60 grams of carbs per hour from sport drink, sport bar, gels, etc.
Keep cool by using the umbrella, fan, ice towels, ice packs, and ice vests
Change clothes and socks at set breaks
If the Heat Rule is IN, take the 10-minute heat break

POST MATCH:

Hydrate with 16-20oz of water or sport drink per 1 pound of weight loss gradually over time before your next match
Complete a USG test with a PHCP
Within 30 minutes of finishing, consume a proper recovery snack of 30+ grams carbs, 15-25 grams of protein, and low fat
Implement post-cooling techniques

The WTA has precautions in place to help you reduce the risk and prevent onset of exertional heat-illness. During a match you have access to multiple cooling options on each changeover:

Umbrella shade
Cold water & sports drink
Ice towels & ice bags
A change of attire break

Additionally, the Extreme Weather Conditions Rule allows you to take a 10-minute break between the second and third set when specified measurements are reached for the heat stress index, (based on air temperature, humidity, & court/sun radiant heat) or apparent air temperature (based on air temperature & humidity only).

10 minutes is adequate time to refresh, rehydrate, and noticeably decrease body core temperature. This can be accelerated by being in an air-conditioned area while implementing proper hydration strategies, cooling with ice and ice towels, and changing into dry breathable clothing and dry socks/shoes.

The contents of the Health site are for informational purposes only and should not be treated as medical, psychiatric, psychological, health care or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this site. Reliance on any information provided herein is solely at your own risk.

A special thanks to the authors, Dr. Michael Bergeron, WTA Hydration and Heat Stress Advisor and Susie Parker-Simmons, WTA Sports Dietitian