Here’s the connection. Blood is the transport system that delivers oxygen, glucose, amino acids, and other vital nutrients to the muscles while removing metabolic waste from the muscles, all influenced by your DNA.

If your blood is 90% healthy, your muscles are 90% healthy...
If your blood is 80% healthy, your muscles are 80% healthy...

(and so on and so forth)

More specifically, your DNA influences hydration/sweat rate, B vitamin use (especially B6, B9/folate, and B12), creatine recommendations, and the specific variations of your MTHFR gene. 

The MTHFR gene is very complicated. (While an AI search will give you basic information that may be inaccurate, the book will provide clear-cut information specifically for athletes.)

One example is the recommended creatine dose based on the 1 of 3 genetic variations of the MTHFR gene. (Of course, these formulas are also based on body weight.)

• The first variation (V1) maintains a 50-50 split between nature (what your body can make) and nurture (how much creatine you should consume through food or supplements).

• The second variation (V2) reduces the nature side of the formula by 40%, shifting the formula from 50-50 to 30-70, thus increasing the amount of creatine consumed through food or supplements. 

• The third variation (V3) reduces the nature by 80%, altering the formula to 10-90, which increases the amount of creatine consumed through food or supplements.