An individuals genetic sequence will not change as a result of exercise training or even a lifetime of a particular type of training. However, over evolutionary time populations living where their environment requires them to adapt to specific physiological conditions, particularly those of interest to exercise genetics, will take place. For a recent example read this paper: https://www.cell.com/cell/fulltext/S0092-8674(18)30386-6.
They show that in a population that require aquatic breath holding to survive (i.e. hunting for food etc.), adaptations in a gene responsible for increased spleen size providing them with a larger reservoir of oxygenated red blood cells (PDE10A gene) were naturally selected and would thus be a useful gene to study in the content exercise generics for endurance athletes maybe.
However, it is well know that any change in the cellular environmental conditions will result in gene expression changes to adapt to that particular environment at that particular time i.e. muscle expression during resistance exercise. But according to the "central dogma of molecular biology" you need the beneficial blueprint (DNA sequence) to elect the beneficial expression (as a result of a specific training stimulus) and get the beneficial result (optimal athletic performance).
@Peter Griepink, I read the same article and come to a different conclusion. The misunderstanding here is that genetic changes manifest over large time frames and not in a directed manner such as exercise --> bigger spleen. Think that someone by some genetic change event had a slightly bigger melt and then could dive longer ... catch more fish ... produce more offspring than others without the mutation. These offspring carry the same 'mutation' and other many generations, this can lead to the selection of large spleen for better diving abilities.
You cannot achieve this by training.
There are some things that can be changed on other molecular levels with different degrees of success (e.g.: methylation of the epigenome). However, without using sophisticated molecular biology methods (think: CRISPR, or other mutation inducers) you cannot change your genetic composition. Even if you would change your genetic composition now, the effect would not materialize necessarily since you already went through development and your cells have already differentiated.
In short, no amount of physical exercise will achieve a change in your genetic makeup especially not something you can control or would find desirable.
Of course exercise can change the genetic expression of an individual. Without exercise and sedentary mode of life lead to many diseases especially diabetes, heart and brain diseases which are nothing but genetic wrong signal. We can avoid such prepond unwanted genetic changes by exercise.
An individuals genetic sequence will not change as a result of exercise training or even a lifetime of a particular type of training. However, over evolutionary time populations living where their environment requires them to adapt to specific physiological conditions, particularly those of interest to exercise genetics, will take place. For a recent example read this paper: https://www.cell.com/cell/fulltext/S0092-8674(18)30386-6.
They show that in a population that require aquatic breath holding to survive (i.e. hunting for food etc.), adaptations in a gene responsible for increased spleen size providing them with a larger reservoir of oxygenated red blood cells (PDE10A gene) were naturally selected and would thus be a useful gene to study in the content exercise generics for endurance athletes maybe.
However, it is well know that any change in the cellular environmental conditions will result in gene expression changes to adapt to that particular environment at that particular time i.e. muscle expression during resistance exercise. But according to the "central dogma of molecular biology" you need the beneficial blueprint (DNA sequence) to elect the beneficial expression (as a result of a specific training stimulus) and get the beneficial result (optimal athletic performance).
As the friends have noted, the gene does not change with exercise, that is, its sequence or its polymorphism can not be changed with exercise. But the expression of the genes is change with exercise, for instance, following a resistance exercise , the expression of Follistatin increases. Recently, a special look at epigenetic changes (HDAC, microRNA, lncRNA etc,) has been made, which changes the expression and function of epigenetic factors accurately regulates the expression of the genes.
Please see some recent studies:
Gjevestad, Gyrd O., Kirsten B. Holven, and Stine M. Ulven. "Effects of exercise on gene expression of inflammatory markers in human peripheral blood cells: a systematic review." Current cardiovascular risk reports 9.7 (2015): 34.
Ling, Charlotte, and Tina Rönn. "Epigenetic adaptation to regular exercise in humans." Drug discovery today 19.7 (2014): 1015-1018.
No doubt that the genecis code (A,G,C,T) will not change in response to any intra- or extracellular stimuli (e.g., exercise). However, exercise might trigger epigenetic changes (DNA methylation, histone modifications, ncRNAs), which will modulate the accessibility to the genetic code. If such epigenetics changes are inheritable, then there is a possibility of ecxercise-mediated epigenetic changes that might result in the selection of fitter individuals. In the literatüre, there are examples of permanent changes in the epigenetic code that can be inherited.
Another possibility to consider is a potential for epitranscriptomics changes in the germ cells. If excersice might induce such inheritable changes, I can forsee a possibility for exercise-mediated epitranscriptomics changes in the germ cells that might change the fate of the fertilezed egg :)