Re: Krav Maga
I take a Krav class at least 2x per week in conjunction with a regular CrossFit routine. This means, in essence, that two days per week I'm doing two conditioning sessions in a day. At 44, I've found that this kind of volume requires a little creativity with CrossFit programing since a typical 1 hour Krav class involves a lot of conditioning and, particularly, extra stress to the shoulders and hip flexors on account of all the drills that include hand strikes and kicking.
You also want to make sure to take care of your hands (wear wraps and gloves) and pay special attention when learning proper technique with open hand strikes and punching. Sprained fingers/thumbs/wrists take a long time to heal and can really sideline your CrossFit training since any "sprain pains" in the fingers/thumbs/wrist will impact your hook grip, front rack position, etc.