If you want to stay strong as you age and your body starts to decline, two exercises are essential, according to Michael Joyner, a physician and Mayo Clinic researcher who is one of the world's top experts on fitness and human performance.
They are burpees and jumping rope.
Why these two?
Your body starts to lose strength as you age. Most people reach their strength peak around age 25, though some research shows marathon runners tend to be fastest at 28. Of course peaks vary from person to person — if you started strength training after 25 and hadn't before, your peak would come later.
To truly stay fit, you need to keep building strength to combat your body's natural loss of muscle mass. That may be the thing that keeps you young longest. As Joyner wrote for Outside magazine, "study after study is showing that simple tests of physical performance are highly predictive of future mortality."
You can build strength in a lot of ways — lifting weights and adding intervals to endurance workouts both work. But burpees and jumping rope build both endurance and strength at once.
Burpees are hard to beat in terms of single exercises that will work your whole body — which is why trainers so often recommend them. Instagram-famous fitness trainer Kayla Itsines recently said that a burpee with a push-up would be the exercise she'd choose if she "had to pick one" for a full-body workout.
"On hard days, I'll sometimes alternate a minute of burpees with sets using a weighted jump rope," Joyner told Business Insider. Ouch.
How to do these workouts
You can do burpees or jump rope year-round, since they can be done outside or in a gym.
It's worth starting slow with burpees to make sure you get the form right. Starting from a standing position, you'll squat down until you can put your hands on the ground. Then kick back into plank position, do a push-up, and kick your legs back into your squat position. Then jump.
Jumping rope is a more straightforward exercise, but Joyner recommends using a weighted jump rope. With the added weight, the challenge is no joke. If you're feeling tough, you can try alternating with burpees like Joyner does.
There are a variety of recommended workouts, but whichever you choose, you'll want to do a series of sets, perhaps alternating with another exercise.
Just remember: These workouts are going to be hard. It's great to push yourself, and plenty of research backs up the strong benefits of vigorous exercise. But it takes time to build up to these kinds of exercises (and practice to get them right). If you're worried you might injure yourself, talk to a doctor or trainer first.
Anyone who wants to attempt such intense workouts also needs to remember to rest. Most trainers recommend alternating between tougher days and lighter days.
"Make your hard days hard and your easy days easy," Joyner said. "Control your pace or it will control you."