As I was browsing articles on GenomeWeb, a news website geared toward scientific things, I came across an article discussing the formulation of training plans based on an athletes underlying DNA. I found this fascinating, and decided to check the company out.

DNAFit is a company that essentially profiles a set of genes for a set of variants that have been linked to athletic performance. A variant can be an change in a single basepair (the A,C,G,T code that makes up our DNA). From their website one specific gene ACTN3 is associated with fast-twitch muscle fibres. Their recommendations for ACTN3 variants:

Alpha Actinin 3

ACTN3

Associated with major structural component of the fast twitch fibres of skeletal muscles. Only present in fast twitch muscle fibres.

CC

Strength, speed and power gene combination (found in sprint athletes). Likely to increase benefit from explosive style training.

CT

Expected to be good at strength, speed and power activities, but less so than RR.

TT

Not associated with power. More frequent in endurance athletes and very rare in elite power athletes.

The list of genes and variants go on and on, all of which I assume have been carefully curated through the many many years of literature and study by the scientific community. One study just coming out in the Journal Biology of Sport suggests that these markers can actually be used, and it showed that athletes paired with the proper training program showed increased gains as compared to athletes in an unmatched program.

For instance, the II genotype of the ACE and XX (Ter/Ter) genotype of the ACTN3 genes (known as endurance markers) were associated (or tended to correlate) with increases in aerobic fitness in response to low-intensity resistance training, while the ACE DD and ACTN3 RR (Arg/Arg) genotypes (known as power/strength markers) carriers demonstrated greater improvement of performance parameters in response to high-intensity resistance training, which is consistent with previous findings [48-51].

I find this incredibly fascinating. It makes sense that certain people would respond differently to different stimulus, but to have actually identified genes of interest, and particular variants and then leverage that to real results is pretty cool. Science! 

For the full reference: 

Jones N, Kiely J, Suraci B, Collins DJ, de Lorenzo D, Pickering C, Grimaldi KA. A genetic-based algorithm for personalized resistance training. 
Biol Sport. 2016;33(2):117-126.