Medical Musings

Dr Billi Glass

"We are just biochemical life forms - Mr Spock.

So says the apocryphal Dr McCoy of Star Trek fame.

He is right. We are complex creatures made up of elements which form our protein, our blood, our brains, our bones, muscles, hearts and even our fingernails.

In the 1860s a famous French physiologist, known to most doctors, described homeostasis - his name was Claude Bernard. Homeostasis is the condition whereby the body remains stable for example energy in is equal to energy lost. If you change something use more energy for example you will lose weight, if you eat more and do not use up the energy, you will gain weight. If you drink a lot and do not get rid of it, you will become waterlogged. If you do not maintain that homeostasis, you might feel unwell. Our bodies must maintain the balance.

I will get you to do a simple experiment at home. Sit down, breathe rapidly for about a minute, and see what happens. Do you feel lightheaded? Are your fingers, your toes, mouth, or lips tingling? If so, it is because you are blowing out too much carbon dioxide. This changes the acid balance in the body changing the ionization state of calcium and affects the way muscles and nerves conduct electricity. If you were to keep doing this, you might even faint. In fact, this is what sometimes results when someone has a panic attack and hyperventilates.

One of the most important things that we need to keep stable is a fluid balance. This is especially relevant for athletes performing at peak and when the atmosphere is hot - which it will be in Israel next July. Note I said fluids, because when you are exercising in a hot environment you sweat more. You lose water and salts. We must replace both. This can be done by purchasing an expensive bottle of brightly coloured liquid from outside your gym. Alternatively, by buying electrolyte tablets, dissolving them in your water bottle and drinking this whilst exercising and during the recovery phase. You might find you drink less and pee less as a result. You will recover better from exercise as replacing salts lessens muscle cramps.

Top-level athletes who train at the Australian institute of Sport (AIS) in Canberra, have their weight measured before and after activity. They have blood tests, their urine and sweat is analysed in order determine exactly which salts are lost and how much. This is especially important for marathon runners. You might have seen runners competing at a high-level, stopping at their own individual booth to pick up their own balanced fluid replacement calculated scientifically specifically for them. This might not be possible for every athlete attending the Maccabiah in July next year, but it is worthwhile considering what weight you might lose in a game of soccer for example. The weight lost will be fluid that you have lost over that game.

You can calculate how much fluid to drink. One litre of water weighs 1 kg, so if you lose 2 kgs during the match you have lost 2 litres of water + salt and most of which needs to be replaced as an electrolyte solution. If you were to replace that fluid as water only you would dehydrate the intravascular compartment (i.e., your blood) making you feel lightheaded, unwell, and possibly causing cramps.

Lesson to be learned - replace all fluids lost with electrolyte solutions not just water.

Try experimenting with this over our summer. You might be able to calculate how much fluid and electrolyte you need when playing a game in the heat of Israel summer.

We will all compete better by competing smarter!!