The AlterG: Training for Reduced Impact When Running

How to use the AlterG for running training.

For those of you who attended our AlterG workshop in November, thank you! We are so glad we get to share our knowledge with our community. For those of you who missed it, here is a recap from runner Karen Lovely, PT, DPT.


If you’ve never tried running on an AlterG treadmill, I recommend trying it out for the sensation of running in outer space.  The AlterG uses positive pressure with an air cushion to effectively walk or run on a treadmill with up to 80% reduction in your body weight.   As a result, we can run with reduced ground reaction forces which decreases the forces absorbed through our knees, ankles, and hips. The AlterG is a great tool for rehabilitation after an injury.  Additionally, it is a useful training tool for non-injured runners to maintain high level performance with less risk of stress related injuries.

When rehabilitating from an injury, the AlterG helps runners return to running sooner than one could run on land.  In addition to the emotional benefits of being able to run again, the AlterG assists runners in maintaining their turnover and decreasing muscle atrophy during recovery.  Furthermore, runners do return to land-based running sooner when they’ve trained on the AlterG during rehab. When is it safe to return to running on an AlterG when an injury forces you to stop your favorite sport? There isn’t enough research yet to establish strict protocols.  However, a physical therapist will help guide you based on your injury and tolerance for tissue loading.

As I mentioned above, the AlterG is also a useful tool for non-injured athletes during training.   Runners can complete high intensity interval training on the AlterG, achieving their VO2 max at higher velocities than one could run on land. Research by Gojanovic et al, 2015 suggests that athletes report reduced pain and soreness post-workout on the AlterG and have similar improvements in time trials when interval training on the AlterG relative to training on a standard treadmill.  

Research does suggest that training on the AlterG can affect the mechanics of running.  However, if bodyweight reduction is kept to 20% or less, the changes in stride are non-significant.  

So what is the bottom line?  

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  • Injured athletes can return to running sooner on the AlterG than they can return to running on land.  This assists with emotional wellbeing, overall fitness, maintenance of turnover, and returning to land based running sooner.

  • For non-injured runners, body weight reduction should be kept to less than 20% when training on the Alter G to maintain a normal stride.

  • Interval training on the AlterG improves performance similarly to interval training on a standard treadmill but with reduced ground reaction forces and reduced post-workout soreness.

Have questions?  Come check out our AlterG treadmill!  Call the clinic at 505-266-3655 to schedule an appointment with our Athletic Trainer, Julie Holt, who will familiarize you with the equipment!


About the Author: Karen Lovely, PT, DPT

Dr. Lovely received her Doctorate in Physical Therapy in 2016 from the University of Wisconsin-Madison.  She enjoys practicing as a generalist, working with a variety of patients with orthopedic injuries and neurological disorders.  She particularly enjoys working with recreational athletes and older adults.  Karen is also trained to treat patients with dizziness, vertigo, and balance impairments.

Karen is a member of the American Physical Therapy Association (APTA) and has section memberships in orthopedics and neurology.  She represents New Mexico physical therapists as a Delegate to the APTA House of Delegates.  

In her free time, Karen will take any excuse to be outside in the mountains.  She is a passionate long distance runner, rock climber, and road cyclist.  Karen is a native of Massachusetts and proudly roots for the Boston Red Sox.


Gojanovic B, Schultz R, Feihl F, and Matheson G.  Overspeed HIIT in Lower-Body Positive Pressure Treadmill Improves Running Performance.  Medicine & Science in Sports & Exercise. 2015; 2571-2578.

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In case you were overwhelmed by the amount of information that was presented, follow our blog online or find us on Apple News for regular updates. Our next article will have some exericises you should include in your training program to reduce your risk of injury.

Thank you again, and please be sure to swing back in, either to see a PT for an injury, work with Julie for an injury risk screening, or to try a MovNat class or run on the AlterG.