Our brains are the driving force behind everything we do, whether it’s completing a crossword, lifting something heavy, or running for dear life away from the neighbour’s Alsatian, which appears to be slobbering at the mouth in anticipation.
Sure, the body is the mechanism it uses to perform the end function, but our brain is the super computer, juggling thousands perhaps millions of tasks at any one time. Some of these actions we are aware of – and can even control. Most, however, just happen; the old noggin gets on with them in the background like any other computer.
To do all of these tasks, whether we are conscious, sub-conscious or completely out of it, our super computer needs fuel. Logically, it uses many of the same fuels as the muscles in our body, glucose and oxygen being two of the more critical ones. It burns calories as fuel to complete the myriad functions it performs – they don’t call it brain power for nothing – and it needs to be supplied constantly. Constantly.
To put it in perspective: the muscles in our rippling bods can hold around 1400 kilocalories of glycogen (fuel form of glucose), the liver – approx. 350 kilocalories, and the blood – about 40 kilocalories (ref. Advanced Sports Nutrition – Dan Benardot).
The blood pumping through our arteries and through our brains is the only source of nutrients the grey matter gets, meaning that when it’s burned through the 40 calories, the blood should get replenished by the liver. If liver stores are low or they get used up without replenishment, or the activity is such that the blood sugar is used before the liver can respond, then the brain is all but out of fuel.
And when it’s out, it goes into emergency power mode and tends to crash a lot. You can have all the glycogen stored in muscles you like, but when the blood is depleted – goodnight Irene!!
Diabetes and Shock
That’s one of the primary reasons diabetics experience the low-blood sugar crash – actually they can go into shock. This is because too much medical insulin can enter their blood stream and snap up all the glucose. With the blood so rapidly depleted of sugar like that, the brain pulls the plug on so many body functions so quickly to save its own power reserve that the person shuts down. This is also known as hypoglycemic shock.
We get most of our glucose from carbohydrate sources, which is why if we eat too much sugary food, we can elevate our blood glucose to dangerous levels. Hyperglycemia (opposite of Hypoglycemia/low blood sugar) can lead to diabetes, and both conditions involve high blood sugar levels, whereby insulin has become ineffective as a result of repeating these poor diet habits.
Role of Exercise
Increasing insulin sensitivity is one way of making sure diabetes never comes knocking. One way of training your insulin to become better at its job is to partake in regular exercise, specifically strength and resistance training. A moderated diet will ensure that blood sugar levels are regulated, and the inclusion of a supplement or two will have you stable as you can be.
Back to the brain though; what happens if you are at the gym, sweating your guts out on a particularly intensive session? Well, fuel is what should happen. Carbs taken during a workout are not only for your body, but your brain.
Carbs and Electrolytes
You probably know that washed-out feeling when you have really gone at it with nothing but water in a bottle to keep you hydrated. Use enough energy and sweat a couple of litres and you’re not only losing water, but salt and sugar, too.
Even if your workout doesn’t last too long, but it’s still intense – say 45 minutes, you will still want to normalize blood sugar and replace the electrolytes you lost from sweat. At my height of fitness, I could run 10 kilometres at 90% max heart rate, but after the first 5 km I would need to start taking some fuel on board. My muscles were crying out from the effort but it was in the hours following it that I would be suffering, and it would be largely due to mental fatigue if I didn’t refuel adequately.
Refuel and Replenish
For your mental energy and cognitive function to remain high following exercise, it’s always a good idea to replenish with carbohydrates during or immediately afterwards. If you take them on slowly, for example by sipping at a maltose-infused drink, then you won’t cause a spike in blood sugar that could be more detrimental than beneficial.
After a while, it will become a matter of feel. If you eat sensibly then the short workouts may not always need any serious fuel other than a few drops of lemon juice in water, or coconut water or something for electrolyte replacement. As important as it is to have a level of blood glucose, it is more important to maintain it. Too much high glycemic (level of impact on blood sugar) foods and you can trigger a negative response from your body.
Importance of Balance
Even non-diabetic people can crash if they eat or drink too much sugar, because their body will react with insulin in force and they will whip too much of the glucose away in no time, leaving little behind for the brain. Balance is therefore important when deciding what type and how much sugar to consume.