Exercise and Dark Meat?

[the simple life]

I was reading past threads here and I saw it mentioned that if you allow meat birds to get too much exercise it will have more dark meat than it would have.
Is that true?

 

[Buster52]

I'm new at this, but it hasn't been my experience. My birds get lots of exercise and don't seem to have all that much.

I wonder if it has something to do with the breed.

 

[silkiechicken]

Dark meat is slow twitch muscle, while white meat is fast twitch muscle, as colored by the amount of mitochondra in each tissue subtype. Each subset of muscle is found in different parts of the bird is the same, but different breeds have different ratio of legs vs breast (ie meat birds have double breasts therefore more white meat). The only thing excercise has to do with it is potential hypertrophy like body builders. But in the scope of things, no it doesn't change the ratio really, as legs will be dark, and breast will be white.