Question and Answer #2. Running and ground reaction forces.


How bad is running for your knees? How bad is it to be overweight and run? What is the best workout if you have only your bodyweight and 15 minutes?


Running itself is not bad on your knees. It’s the constant jarring and impact from the forces that are created from each step you take that isn’t so good.  Ground reaction forces can go up to 7x your bodyweight based on your running speed. For example, if a person was 260 lbs and they were running fairly quickly each step they take can be up to 1820 lbs of force. Imagine running a mile the force can quickly add up and increase risk for injury.  That is why individuals that are heavier should stick to exercises that don’t generate as much force. Such as using a treadmill, cross trainer, bike, swimming or resistance training as a form of cardiorespiratory exercise.


For the vast majority of healthy individuals with no orthopedic problems in their lower extremities jogging, running and sprinting is perfectly fine. But remember anything done in excess may lead to problems. For those of you with ankle, knee, hip, and or low back issues, you may want to recover from your injury first before running again.

The best workout a person can do depends on the goals of the individual. For a healthy fit individual looking to maintain or increase their fitness levels. A combination of sprints, push ups and bodyweight squats (single leg squats if possible) would give you a good run for your money.

In Strength,

Charles Trinh, MS, PES, CSCS, ACSM-cPT

Please feel free to share this post, in return please credit me as the original author of this work, include a link to this post and the bio at the end of this blog.

Charles has dedicated more than 14 years in the field of exercise science and performance enhancement. His extensive background in human performance and sports medicine enable him to develop scientifically sound fitness programs for individuals looking to get healthy, and up to high performance athletes.  Charles has also done extensive work with the National Strength and Conditioning Association (former state director) and American College of Sports Medicine in providing continuing education units to personal trainers, strength coaches, physical therapist, athletic trainers and Medical Doctors. With his extensive training and experience, Charles has helped countless individuals reach their health and performance goals.



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