Impact Facts

You’ve probably heard the term low-impact exercise, especially if you’ve ever visited a physical therapist or had to recover from an injury. But what makes an exercise low-impact rather than high-impact? What are the benefits of each and how much should you try to incorporate them both into your fitness regimen? To help sort out the answers to these questions and more we consulted J.D. Whittemore, a Board Certified Clinical Specialist in Sports Physical Therapy and Clinic Director at Texas Physical Therapy Specialists’ Westlake location. e probably heard the term low-impact exercise, especially if you’ve ever visited a physical therapist or had to recover from an injury. But what makes an exercise low-impact rather than high-impact? What are the benefits of each and how much should you try to incorporate them both into your fitness regimen? To help sort out the answers to these questions and more we consulted J.D. Whittemore, a Board Certified Clinical Specialist in Sports Physical Therapy and Clinic Director at Texas Physical Therapy Specialists’ Westlake location. 

The difference between high and low-impact:

For an exercise to qualify as low-impact, one foot must remain planted at all times. By this definition, walking is considered low-impact while running is considered high-impact. At a certain point in a running stride, both feet are off the ground at the same time—simple enough.

Basketball, jump roping, burpees, and running are all high impact activities while cycling, rowing, and walking are all understandably low-impact. 
The terms high-intensity and low-intensity refer to heart rate. There is a common misconception that a low-impact exercise is also low-intensity, but if you’ve ever taken a spin class or done intervals on the rowing machine, you’ll know that’s not true. 

“A lot of people say, ‘My doctor told me I should never do high-impact activities again’ and they think they're doomed to having to perform something that’s slow and methodical,” Whittemore says. “But you can turn high intensity interval training into a low impact session, it’s just about exercises that you select.”

Is swimming considered low-impact?

The short answer is yes, but the long answer is a little more nuanced. While swimming does not put the joints under significant stress, it’s more commonly referred to as an “unweighted” exercise rather than a low-impact exercise. Low-impact exercises like walking, rowing, and cycling require your muscles to support your bodyweight. Swimming lightens the load so that your muscles don’t have to support your full bodyweight or absorb much impact at all. 

Whittemore says that swimming can be a good aerobic workout and help build muscle. With guidance from a physical therapist, it’s an especially effective workout for those recovering from injury or surgery. 

Where does weightlifting fit into all of this?

By the strict “one foot on the ground at all times” rule, weightlifting would be considered low-impact, but the definition changes when upper extremities get involved.

An overhead press, for example, can still be considered high-impact, depending on the level of resistance and velocity. 

“If you're doing an activity like [overhead press] where you have a high-load that is quickly put through the joint, then you are beginning to go into a high-impact activity for the shoulder,” Whittemore says. 

If you can distribute the force over multiple joints and muscles, you’ll put less stress on a single area.

“Generally, you want to start with the exercises that are going to involve multiple joints and multiple systems and then as you go through the routine you end with the more isolated joints or the isolated muscle groups,” Whittemore says. 

Bulgarian split squats are a great example of an effective, low-impact lift that is particularly useful for runners. “It puts you in a running position and it’s going to help you utilize more of your glutes, hamstrings and quads,” notes Whittemore.

He suggests starting with bodyweight resistance and then progressing to holding dumbbells as you gain strength and stability. No matter what impact level, keeping a strong form is the most important way to prevent injury.

“It always comes down to form. You never want to compromise that to increase the velocity or add weight to an exercise,” Whittemore says.

Does this mean that avoiding high-impact exercise entirely is the best way to prevent injuries? 

No—unless you are currently recovering from injury or surgery, or coping with arthritis, it’s healthy to incorporate a combination of high-impact, low-impact and unweighted activities into your routine. Gaining strength through low-impact weight lifting helps build bone density and also prepare muscles to absorb the forces created by high-impact activities. While high-impact exercises are a more effective way to build explosive power, unweighted activities provide relief to joints while still increasing aerobic capacity. Each type of activity complements the other and helps round out a fitness regimen to prevent injury and optimize performance. Whittemore says that the most important components of any routine are good form and fun.

“The best thing for you to do is consider what’s important in your life and find the proper muscles that you need to build up for what you're going to be doing in your daily routine, hobbies and activities,” Whittemore says. “It needs to be something that interests you, that way you're more likely to continue on with it.”