6 Ways Running Affects Your Body Way Differently Than Walking Does

Running and walking both move your body forward, but the mechanics are different. When you're walking, you probably step forward with your heels touching the ground first. You want to avoid this when you're running, though.

"The typical (or ideal) foot-strike in running is landing on the mid-foot, pronating, and leaving off of your big toe; whereas in walking, there is more of a heel strike involved," says Steve Stonehouse, a certified personal trainer, track and field coach, and director of education for running studio franchise STRIDE.

This difference in stride also impacts which muscles are used, says certified personal trainer Karen Shopoff Rooff. "With the heel strike of walking, the hamstrings are worked more than they are in running. Conversely, the quads are used more in running than walking because of the spring-like propulsion off the foot when running."

Because of the difference in your gait and speed, running has more impact on on the joints than walking. "The change in strike area on the foot increases the forces sent upward through the body as you land further forward on the foot," Rooff says. If your form is correct, this can be positive. But if your form is off, you may injure yourself while running. Paying attention to the way your foot hits the ground can help you run in a way that maximizes the benefits and minimizes the downsides.

Running with proper form means that your body can absorb the shock more safely. Solid form means that your body "is able to convert [running impact] into rotational momentum, decreasing the impact on the body," says Emily Paskins, a certified personal trainer for at-home personal training community iFit Training.

"Running produces a much higher ground reaction force on your body than walking does," says Chatzopoulos. "If you're running with proper form, then your muscles, joints and tendons will accept this force and actually use it to help propel your body forward." However, running without great form can increase your risk of injury, especially compared to walking.

"To make sure your body doesn’t crash excessively with each foot strike, you want to run tall and with quick feet," says Nate Helming, co-founder of the training community The Run Experience and strength coach for the running app Strava. "The less time your foot is on the ground while running, the more likely it will land underneath your body, and the less likely you’ll crash and collapse with every step."

In addition to locking in your form, Helming says that you can reduce the risk of running injury by slowly introducing your body to the exercise. "You want to work your way up slowly to greater volume to give your body the time to adapt," he tells Bustle. "Short sessions of 10 minutes or less combined with strength training and run drills are a great place to start."

"Physical exercise is considered an effective way to stimulate formation of bone," Paskins tells Bustle. Exercises like weight training and running boost your bone density because your body adapts to having more pressure on your joints, which can actually be a good thing. The more your bones get used to healthy pressure, the less likely they are to break. "Running can lead to more injuries, but it has also been shown to lead to better bone density, better circulation, and improved muscle and tendon function," says Chatzopoulos.

There's a reason walking feels less strenuous than running, and it's because people tend to expend more energy on a run than a walk. "In general, you’ll typically expend twice as much energy running as you may walking," Stonehouse says. According to a 2020 study published in the journal Scientific Reports, the faster you move, the more energy you use. So if you're short on time and want a more intense workout, you might want to lace up your running shoes instead of your walking boots.

Long-distance running can have a negative hormonal impact on some people, especial those with hypothyroidism. "They may find that the training stresses of running exacerbate their thyroid imbalance," says Rooff. "Distance running creates a physiological reaction of stress in the body, as your body doesn't know the difference between running from a lion attack for two hours or running for fun. This chronic stress taxes your thyroid and can lead to fatigue ... and depression."

Getting enough rest and nutrition between your running sessions is vitally important for making sure your body can calm down and know that it's safe. If you get unpleasant symptoms from running, see a doctor, who can help check on your hormone health and offer some tips on rest and recovery.

Studies Referenced:

Li, S. (2020) Comparison of energy expenditure and substrate metabolism during overground and motorized treadmill running in Chinese middle-aged women. Scientific Reports, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7000674/.

Experts:

Ambyr Chatzopoulos, certified strength and conditioning specialist

Steve Stonehouse, certified personal trainer, track and field coach, and director of education for STRIDE

Emily Paskins, certified personal trainer for iFit Training

Karen Shopoff Rooff, certified personal trainer

Nate Helming, co-founder of The Run Experience, strength coach for Strava