Kefir is a drinkable cross between milk and yogurt. Here's why you should consider adding it to your diet plan:
Kefir is loaded with good bacteria that help keep your digestion in top shape so that you can you can extract all the calories and nutrients from the massive amounts of food your body needs. The good bacteria also strengthens your immune system.
Kefir has more protein than milk or regular yogurt.
The lactose, which many people can have trouble with, in kefiris essentially non-existent because the good bacteria in it pre-digests it for you.
It also has calcium and vitamin D, two nutrients for bone health so that your body can continue to withstand the pounding of intense training. I consistently see my athletes having low intakes of these two nutrients.
I use kefir in shakes instead of water to get in more calories and a punch of extra nutrition. Just get the kind that hasn't had a lot of sugar and other junk added to it.