Thursday, November 1, 2012

Fighting Fatigue

Fatigue seems simple: your body has reached its limit, you're tired.  The current understanding is that we feel exhausted because of physical factors. Not enough oxygen and fuel to the muscles and decreased blood flow to the brain means that your muscles are no longer able to generate power no matter how hard you try.  While this is true, it may not be the only factor in feeling fatigued.

A recent study shows that our perception of the effort involved of performing a task has a large influence on how we feel.  Everyone has experienced that feeling of having a "second wind" when the end of the race or top of the hill becomes visible and somehow we scrounge up enough energy to reach our goal.  This study examined the idea of how effort through exercise feels towards your brain instead of how tired our muscles feel. Turns out we become exhausted, not from something that is lacking in our bodies, but because it gets to feel too tough; the pain of continuing outweighs the reward for going on.

So, what can we do to train and adjust these perceptions?
  • Get fitter - Being stronger and fitter will make everything feel easier; simple strength training can go a long way.
  • Tea or Coffee? - Caffeine does enhance performance, mostly by stimulating the brain although there is a limit to what you can achieve from either beverage.
  • Train with friends - Train with people who are around your fitness level, since struggling to keep up with your companions will make the workout feel harder and less enjoyable.
  • Wear the right gear - The best clothes and gear will not make you any fitter, faster or stronger but if you are exercising outdoors, being warm and dry will reduce the perception of effort and may decrease your feelings of fatigue.
  • Rest your brain - If you are reaching for high performance it's important to give your brain a rest.  If you are feeling tired and distracted you will probably find you give up easier and everything will feel tougher.
  • Pace yourself - Pushing too hard too fast results in a quick burnout.  Keep yourself at a pace where your breathing is increased but you aren't gasping for breath.
If all else fails smile!  Maybe there really is some truth to the phrase "grin and bear it!"

References from the SIRC Collection: 

1. Ansley L, Petersen D, Thomas A, St. Clair Gibson A, Robson-Ansley P, Noakes T. The effect of breathing an ambient low-density, hyperoxic gas on the perceived effort of breathing and maximal performance of exercise in well-trained athletes. British Journal Of Sports Medicine. January 2007;41(1):2-7.
2. Fery Y, Ferry A, Vom Hope A, Rieu M. Effect of physical exhaustion on cognitive functioning. Perceptual & Motor Skills. February 1997;84(1):291-298.
3. Hutchinson J, Sherman T, Tenenbaum G, Martinovic N, Rosenfeld R. Perceived and sustained effort and task related affect: The mediating role of self-efficacy. Journal Of Sport & Exercise Psychology. July 2, 2007;29:S171-S172.
4. Morree H, Klein C, Marcora S. Perception of effort reflects central motor command during movement execution. Psychophysiology. September 2012;49(9):1242-1253.
5. Morree H, Marcora S. Frowning muscle activity and perception of effort during constant-workload cycling. European Journal Of Applied Physiology. May 2012;112(5):1967-1972.
6. Wallman K, Sacco P. Sense of Effort During a Fatiguing Exercise Protocol in Chronic Fatigue Syndrome. Research In Sports Medicine. January 2007;15(1):47-59.


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This study examined the idea of how effort through exercise feels towards your brain instead of how tired our muscles feel.
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thanks for share.