At Maggie's Farm, perhaps we discuss weight training more than the other aspects of fitness. That might be because weight training requires more technique to get it right.
However, it seems to me that daily Calisthenics would be the thing to do if you had to pick one thing. Why is that?
A cali routine puts every muscle to work. It doesn't build big strength much, but that's another topic. A cali routine involves lots of HIIT cardio. A calis routine works on balance, and general athleticism. And, unlike heavy weights, an hour of calis does not require any special recovery time so it can be done daily.
It is more fun to do these in groups or couples, and it is more fun to rotate from one thing to another. It doesn't matter what level you work as long as you push it. One hour goes by fast.
Here are some of the things we do:
Warm-up (5-7 minutes): Jumping jacks, jump rope, high-knee running in place, etc.
Push-ups (any sort)
Kettlebell swings
Box squats (with or without weight)
Heavy rope slams
Ladder drills
Box steps or box jumps
Planks
Inclined TRX pulls
Leg raises
Heavy ball throws and chest passes
Lunges
Burpees
Rower sprints
Heavy rope slams or arm machine sprints
Chin-ups (assisted)
Hand-weight curls
Superman
Kettlebell Farmers Walks
Sit-ups
wall-to wall sprints
Bear Crawl
Wall sits
If not heavily sweating, nothing is happening. Add on a 10-minute treadmill walk to cool down. You do not want to put a horse up wet...