Toolbox Genomics - Food & Lifestyle for Your DNA

Published on March 23, 2017

What is the Best Type of Exercise for You?

Ever wonder which type of exercise is most effective for you? Check out our explanation of how your genes play a role in determining the various muscles types and how they influence your workout.


What is the best type of exercise?

Do you like sprinting or long distances? Do you like HIT (high intensity training) type work outs or do you fatigue too quickly?  Is it a lack of self discipline or not having enough time in a day?  Maybe, but there is a greater likelihood that how you workout and more importantly how you enjoy working out is being influenced by your genes.

Just as we have genes that code for various enzymes which help us utilize certain nutrients more or less efficiently, we also have genes that code for different types of muscle fibers.  There are slow twitch muscles and fast twitch muscles.  Everyone has a combination of the two muscle fiber types but the proportion of each can vary depending on the individual’s genetic makeup.   People with more “slow twitch” muscles tend to perform and respond better to endurance training for managing fitness and weight, while people with more “fast twitch” muscles do better with short bursts of speed and lifting heavier weights for shorter duration.


Some key features of slow twitch muscles

  • Contains mitochondria which uses oxygen to help power the muscles
  • Red in color because they contain myoglobin
  • Have their own energy stores and can undergo long periods of force
  • The first to respond with muscle contraction
  • Maintain posture
  • Can increase amount of mitochondria through endurance training and improve


Some key features of fast twitch muscles

  • 2 types: IIa depends on oxygen to change glycogen to ATP and IIb depends on ATP housed in the muscle cell
  • Hard to activate. Only becomes active after the force demands on the muscle exceed the ability of slow twitch muscles
  • Reaches maximum force quickly and exerts greater force than slow twitch but easily wears out
  • Specific exercises help increase amount of fast twitch muscle fibers
  • White in color from the lack of blood


Exercise suggestions


Endurance Group

You are going to benefit the most from sustained heart rate training at moderate levels.  While strength training as well as cardiovascular exercise are both important for a balanced exercise routine you will get more benefit from the cardiovascular exercise than others.  When you lift weights you should focus on a circuit training style that involves higher repetition exercises (10-20 repetitions) moving continuously between upper body and lower body exercises with minimal rest.


Speed/Power Group

You are going to benefit the most by training in short bursts of speed and lifting heavier weights for shorter duration. Training your fast twitch muscles requires a higher level of conditioning and can present a higher level of risk so make sure that you are cleared by a medical doctor for high intensity exercise and proceed gradually if you are just getting into exercise.


For examples of workout suggestions, please log on to your report.



  1. Armstrong, R.B.: Muscle fiber recruitment patterns and their metabolic correlates.  In Exercise, Nutrition and Energy Metabolism.  Edited by E.S. Horton and R. L. Terjung, New York, Macmillan 1988.
  2. Costill, D.L. et al.: Skeletal muscle enzyme and fiber composition in male and female track athletes. J. Appl. Physiol., 40:149, 1976.
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