It’s hot. It’s a summer in Sydney and the time for being out and roaming around, enjoying the sun and harbour, the beaches and the mountain walks to crisp, picturesque waterfalls.  This is why we live in Sydney!  We all feel more motivated to get out and be part of the outdoors a bit, be in the sun and preferably near cool water areas rather than inside in the heat. For some of us, it’s so much easier to get up and jump on the bike, strap on the runners and get out and exercise.   You are motivated to be part of it and be exercising.

The big thing about exercising in the heat is staying hydrated.  Even for those of us who don’t really exercise as such but are doing more activity in the sun, we need to be mindful.  Everyone knows about it and everyone 'aims' to stay in tune with their hydration, but do we really understand how to tell if we aren't getting enough hydration? 

The big issue is when the weather warms up - so do we!  Our bodies will always try to remain at a fixed temperature of 37 degrees Celsius. When this changes, as it does in the heat - we need to change the equation, primarily by sweating.  When this happens - we lose fluid.  Now the body is approximately made up of 70% of water and the blood itself is 80% water.  So if we lose fluid we risk upsetting this delicate balance.  When the body is unable to maintain homeostasis (balance) in this way, then the system begins to deregulate. 

Dehydration means that the body starts to store heat rather than change it - which is when internal organs and neurological change begins to effect body systems and those awful symptoms of heatstroke begin to rise.

Many people hate sweat - they despise it.  But a sweaty body is a healthy body.  It means the body is regulating itself and still capable of maintaining that internal balance of temperature that is all important for optimal function. It is more the inability to sweat that is a problem rather than being concerned about the unsightly patches of dis-colouration under your armpits of your shirt that are the problem.

Dehydration means that your performance is hampered.  You can't expect to go out in the heat and run off a PB in the lunchtime run.  You need to be ready for the heat and acclimated.  Performance athletes spend no less than 2 weeks preparing for ‘heat-induced’ conditions.  Just look at the am0unt of tennis players that suffer from cramps when the temps in the Australian Open soar above 35 degrees!  Cramping is a sign of dehydration.  So be aware when it is hot that you need to pace yourself and RESPECT your limits.

Let's talk about URINE.  Yep - its something everyone does and it is a great indicator of your hydration.  I had a naturopath who was big into Poo.  She believed it held the best insight into what was going on in your digestion than anything.  Looking at it, being aware of it - yeah disgusting but PRACTICAL.  The same stands for urine.  Just noticing the colour makes an impact on your awareness.  A darker colour indicates a lack of hydration and the kidneys working harder to excrete by products of digestion and processing food and fluid intake.  A lighter colour (that of lemonade) indicates a healthy hydration level.  Had a night out on the vino?  Take a look at your urine the next morning - it has an impact!!!

What you eat has an impact on your hydration levels.  Heavy protein laden meals create heat in the digestive system.  The body requires a lot of water and fluid to process iron rich foods.  In the heat, this is an issue as whilst you may not even realise it, your body is needing fluid to process that BBQ with the mates by the beach.  The danger is ingesting too much protein when you don’t have enough water – this encourages dehydration.  Several studies such as those conducted by University of Connecticut Graduate William Martin support that Blood Urea Nitrogen (BUN)levels reach the abnormal range when ingesting a high protein diet.  The risk is that most people won’t ‘feel’ thirsty under these diets but their levels of hydration are significantly hampered.  As little as 2-3% change in body fluid levels can negatively impact on normal performance.

Sugar and sodium are the other concern.  We lose water through urinating.  When ingesting sugar not only do blood insulin levels rise but water is excreted through the urine and the kidneys. The other issue is that sugar creates an acidic environment that impairs enzyme activity and the body’s ability to store water.  The same stands for sodium (salt), which is used to process sodium in the body but also encourages urination.  Sodium is eliminated through urine and pulls water with it.  So eating salty foods before exercising is not the greatest preparation for exercise.  There goes that idea of ‘running off the burger and fries”.

Sitting in office air conditioning and avoiding sweating is not a solution.  Being in an air-conditioned environment is like tipping water into a frying pan on full heat.  Air-con dehydrates the body.  It draws fluid outside the body as the body tries to maintain a moisture balance between the internal body and the air around you.  Air-conditioned air is a false environment and it dehydrates the system.  

If the air conditioned air is too dry, as is often the case, water evaporation from the surface of the eyes and the upper layers of the skin will accelerate, resulting in dry skin and dry eye complaints
— Sharon Kleyn - Power of Water

The big impact is wind and the wind generated from air conditioning, strips away the top layer of hydration which then causes further fluid evaporation to combat the dry air on the outside surface.

It is also important to realise that your clothing has an impact as well.  Exercising in hoodies and track pants with your best ‘bling’ on and looking oh so cool in the heat isn't a great idea!  This makes a difference to the power muscles such as the larger muscles in the leg which should be free and unencumbered so that they dont' sweat as much and don't lose fluid!  I heard a story of a leading Australian Ballerina who used to wear sweat pants and wrap her legs in Glad Wrap on long haul flights so as to maximise her loss of fluid!  Crazy when you think about it.  Now that may be well if you're starring opposite Rudolph Nureyev but for us lesser mortals, let's be sensible.  Really - get your chests out there - Boys and girls.  And let the world see those thighs.  Its better for all of us!!!

Signs of heat exhaustion include general fatigue, weakness, nausea, dizziness, muscle cramps, and an increase in body temperature.  You may not think much of it when you are on the court and working hard in your training or with your coach.  But if you start to feel headaches, or itchy eyes or nauseas – these are the first signs of dehydration.  It’s not just your body pushing you through the first training session of the year, it’s the dehydration of your cells.  Don’t ignore it.  Ensure that you take the necessary steps to prepare and avoid a water depletion situation occurring.

In short it comes down to being sensible.  Making sure you keep the water intake up throughout the day (recommended dosage is 2L minimum per day and more if you are exercising) and ensuring that days BEFORE a large event, you really do hydrate up as much as you might carb up, is important.  Its a simple thing, but it makes a big difference to how we work, act and play.