Our trainer suggests first-thing-in-the-morning (after coffee) daily calisthenics when away from regular training. That is in addition to all other physical activity (eg hiking, swimming, running, biking, yoga, garden work, etc) which he assumes active people do on weekends or on vacation. In fact, he recommends morning calisthenics for everybody of every age and condition whether they work out or not.
Readers know that calisthenics do not build strength. They build endurance and athleticism, help maintain strength by putting all muscles to use, and involve bursts of intense cardio. Very little equipment needed for this program: heavy ball, jump rope, 10 lb dumbells. Lots of core in this.
But first, a stretch/warm up of a short distance of lunges, sumos, side stretches, and toe-touching walking. All outdoors is best regardless of weather. Great fun. I think we'll have a good bunch for this each morning at 630. For a bunch of them, it will just be a warm-up before their 15-mile run and one-mile swim, but they are nuts. In damn good shape, tho.
Then 3 sets of each 3-exercise circuit:
Squats with 10 lb overhead press, 15 reps
1 minute jumping jacks or jump rope
Heavy ball floor slam, 15 reps
30-sec side shuffle returning to squats
30-60 second rest after completing that circuit 3 X
Jumping squats, 15 reps
30 second side-shuffle
Shoulder-slap arm planks, 15 pairs
30-secside shuffle back to jumpers
30-60 second rest after completing that circuit 3X
Mountain climbers, 15 pairs
30-second sprint or jog
Burpees, 10
Sprint or jog back to climbers
30-60 second rest after completing that circuit 3X
Sideways heavy ball throws (game of catch), 10 each side
Arm plank 1 minute
30-seconds of lunges with 10 lbs in hand
then back to throws
Time up before finishing the last circuit? Then alternate the circuits on different days and just do 3 instead of all 4 routines. Still have a little time left? Can finish up with some elbow planks and/or light-weight arm exercises: high-rep curls, side lifts, forward straight-arm lifts with the 10 lb dumbbell.
It sounds easy, doesn't it? A good way to begin the day. Try it, and get it all in under 60 minutes. If this is too easy, you are pretty fit. It leaves me like a limp rag for an hour.