If your running routine is getting boring, you don’t have to stick to it to get an adequate amount of cardio.
Make an adjustment; There are many ways to incorporate cardio into your exercise while putting less stress on your knees than running does.
Jumpstart your cardio by:
Jumping Rope: Jumping rope for a set amount of time is sure to give a burn. It strengthens and tones practically every muscle in the body. For beginners, a nice start can be done by doing 20 to 30-second bursts. Seasoned jump ropers can do 60 seconds or more.
Shadowboxing: There’s no impact on the knees and you’ll still sweat. Some of the fittest men and women stay fit with shadowboxing. Get your sweat equity by throwing punch combinations while keeping your core tight. It's also a good way to remind yourself that you're tough - inside and out.
Rowing: This has been catching on in recent years, but it's always been a beast of a workout. When rowing a boat, you have to keep going and going. This exercise uses practically all of your muscles from your back, core, and shoulders and definitely engages the muscles below, such as your quads. Beginners aim for 20 strokes per minute in 3 minutes and rest for 1 minute.
Just as we switch up our weight training regimen, we can treat cardio the same, using different exercises to strengthen the lungs, heart, and other muscles throughout the body.