Gist
Yes. Dancing is excellent for general fitness because it can combine cardio, balance, coordination, mobility and muscular endurance in an enjoyable activity.
Yes. Rucking is useful for general fitness because it combines aerobic exercise, weight-bearing movement and whole-body strength-endurance, but it should complement rather than replace strength training.
Yes. Swimming is excellent for general fitness because it combines aerobic conditioning, muscular endurance, coordination and low-impact full-body movement in one activity.
Yes. The elliptical is good for general fitness because it combines low-impact cardiovascular exercise, lower-body muscular endurance and optional upper-body involvement in one machine.
Yes. A rowing machine is excellent for general fitness because it combines cardiovascular training, full-body muscular endurance and low-impact movement in one exercise.