PT on the Net Research

Body Type and Exercise


Do you have any research on training clients according to their body type (e.g., endo, meso, ecto, etc…)? I read an article on muscle fiber types and wonder if there was any other similar articles on the area?


Genes play an important role in how an individual adapts to training stimuli. However, the focus is not on their “body type,” but the adaptation they are looking for. There is no significant research that states a person should be trained any differently because they are a mesomorph, endomorph or ectomorph.

For example, muscle fiber types determine genetic potential, and may be displayed by these body types. Each individual is born with an array of muscle fiber types ranging from type I-slow-twitch to type IIa and type IIb-fast twitch. There are several variations of this spectrum of fiber types, but to keep things simple, these three will suffice. Given that each muscle carries a percentage of both fiber types, some muscles carry a higher percentage of one or another, and some people are born with a higher percentage of one or the other overall. This can be shown by an individual’s inclination towards certain exercises or activities. Some people enjoy running long distances and are better at it than others who would rather lift heavier weights. Taking all of this into account, clients will adapt to imposed demands. Using the SAID principle (specific adaptation to imposed demands), every client will adapt to the stimuli given to them. The rates at which changes are encountered and the potential for the specific adaptation will vary per each individual.

Please remember that acute variables such as reps, sets, intensity, tempo and rest periods determine what type of adaptation being sought and eventually achieved. Everybody displays a different genetic potential and using training principles that have been researched and quantified by clinical experts will provide the results desired.