13 Jul Increase Your Exercise Intensity

• Why your Brain Inhibits Exercise Intensity
• How it Prevents you 
• Develop Mental Toughness to Overcome this

For the last 25 years I have followed the research of Tim Noakes who is a South African scientist, and an emeritus professor in the Division of Exercise Science and Sports Medicine at the University of Cape Town. He has run more than 70 marathons and ultramarathons and is the author of several books on exercise and diet.

He has proposed that the brain regulates exercise so that its intensity cannot threaten your body’s homeostasis – control of water content, temperature, carbon dioxide level and blood sugar level.

Put simply the brain limits intense exercise by reducing the neural recruitment of muscle fibres. This reduced recruitment causes the sensation of fatigue. This isn’t a physical event but a sensation emotion, invented by the brain to prevent catastrophic harm. Tim Noakes has called the brain system that does this the “Central Governor.”

Photo – Jonathan Colon – https://skatesphere.com/

The Central Governor idea goes up against the theory that you simply stop exercising because your body has hit its physical limits by recruiting all your muscle fibres that have now run out of oxygen or fuel, or become damaged by the accumulation of toxic by-products such as lactic acid. This in turn triggers pain and fatigue, forcing you to stop exercising until you recover.

However Noakes’ studies have shown that although levels of fuel inside muscles (glycogen, fat, ATP) do diminish with exercise, they never run out. You might have thought, as you tire during exercise, your body would recruit more and more muscle fibres until there was nothing more to give and you eventually would collapse, exhausted.

But Noakes found the reverse. Through tests he carried out with cyclists as they neared exhaustion, muscle fibres were being switched off. Their brains collated all the information they received from their bodies, such as the level of oxygen in the blood, core body temperature and signals from their muscles that “burned” through their intense efforts. When these parameters reached a certain level, their brains messaged their muscles to stop working at that intensity which was a cue for stopping all together.

His cycling volunteers said they felt too fatigued to continue and yet Noakes had evaluated that they were never activating more than about 50% of their available muscle fibres. Exhaustion forced them to stop exercising, yet they had a large reserve of muscle just waiting to be used.

All of this convinced Noakes that the previous theory of fatigue being caused by muscles pushed to the limit—couldn’t be true. His theory states that the Central Governor shuts down your physical activity in advance ensuring a safe margin of error and allowing you to continue to function, even after an exhausting challenge.

So how can you train your brain to go beyond the Central Governor process and recruit more of those available muscle fibres and ultimately increase your fitness?

Well this is where you will need to call upon another brain related activity –  your Mental Toughness. So how can you get mentally tougher? Well here are some ways to achieve it.

Visualisation. Picture yourself achieving your fitness goals. For instance, if you’re struggling to take your squat weight to the next level, spend a few minutes every day visualising yourself lifting that heavy weight. Get all your senses involved – feel the heaviness of the weight, listen to your breathing pattern, see yourself successfully squatting that weight. It’s a powerful way to utilise the mind.

Distraction is a good tactic to build your mental toughness. Music can be used to do more than just accompany you during exercise. It can get you through a challenging workout when your brain is screaming at you to stop. Line up a track of music that has the right tempo and volume to distract you and play it just when you need it.

Another distraction tactic is to view the burn or exhaustion as your ‘friend’. I remember using this approach during the second half of the New York Marathon when my quads were taking a hammering on the flat roads. I was very sore and still had 8 miles to run. Instead of feeling negative about the soreness which I knew was only going to get worse, I just thought to myself that the soreness was not the ‘enemy’, it was just my ‘friend’ joining me for the run. If it wanted to accompany me to the end of the race then I was ok with that. The soreness turned from being a problem and the creator of a probable slower finishing time to a healthy distraction that focused my attention on enjoying the race atmosphere and keeping my pace up to finish in the 3:30 time I was aiming for.  

Counting helps to engage your brain in another activity when you’re right at your physical limit. For instance, If you’re out running or cycling hill repeats, then counting 1,2,3, etc through the exercise is a way to distract yourself from the fatigue you’re feeling so you can push on to the top.

From a personal perspective I have used all of these tactics at some point in my training and there is no doubt that they work for me.

The Bottom Line?

One of the brain’s key roles is to protect you. However, making greater fitness gains often means silencing that little voice in your head that tells you that you have to stop. You can do that by pushing past what you think you can do through the development of mental toughness using Visualisation, Distraction and Counting to help.

If you have any questions about this article or want to discuss taking your training to the next level, feel free to contact me at fraser@fjfit.co.uk