There are no alternatives to aerobic activity and strength training, because they are the pillars to improved health, body composition, et all. Along the same line their alternatives to improving your health, not replacing standard aerobic activity and strength training. The alternatives are limitless when utilizing your imagination, for example consider your geographic location. For example, I live in Honolulu, therefore utilizing the ocean, such as surfing, paddleboarding, swimming, and hiking, could be very beneficial to improving my health. Now, go out there look around and see how innovative you can be with your surrounding - no geographic location should be overlooked. You are only limited to your imagination. Take charge of your life!:) Mahalo.