I've been a bit fan of walking for years. Look! Fat Loss Mondays - loose [sic] the fat!
Back then, it was mostly about fat loss, although somehow I knew there was more to it. Health, of course, but that is a nebulous concept at best. I just knew movement was critical.
Today, I'm even more sold on the idea that walking is critical for health.
Traditional cardio is not critical.
Strength training, which I love, is not critical past a certain point. I mean how strong is strong enough? Do I need to lift more than 425lbs? Should I keep going up?
Sprinting? Yes. Be prepared enough to get away from whatever's chasing you.
Here's my hierarchy:
Rest - lots. If you don't have enough rest, don't move on to the next level.
Lift - a little. 2-3 times per week unless you have a strength or skill goal. Lift vigorously, too. There's no need to rest 5 minutes between sets unless you have a specific strength or skill goal.
Rest even more - Rest enough to recover from all of the above. If you don't, don't move on to the next level.
Sprint - a little. Once a week should be fine. I recommend Hill Sprints because they are safer and self-limiting. Don't go to the track and sprint. You'll hurt yourself.*** Trust me.
Walk a lot
Walk a lot. Get in your rest. Lift some weights or do your bodyweight exercises. Rest some more, and sprint if you still have it in you.
* good shoes aren't 'walking shoes' from the walking store. Those overbuilt monstrosities do more harm than good, but that's beyond the scope of this post. I'm working with the wife to get you some good shoe and barefoot instructions.
** you have to earn the right to exercise barefoot. It sounds good on paper, but if you've always worn shoes, you're simply not prepared. Like I said in the first asterisk, I'm working with the wife to get you some good shoe and barefoot instructions.
*** the most common injury for recreational sprinters is a hamstring pull or tear. That's you, and you simply are not strong enough to sprint on flat ground. It's also not fun, where hills are. Hill sprints are the key to safe sprinting, so do those.