Walking is good for you.

It’s simple and it’s accessible, and regular walks reduce the risk of many health issues including depression, diabetes, and even some cancers.

But regular-paced (i.e., leisurely) walking is considered “light” physical activity.  Light physical activity does not create new mitochondria, nor does it restore aging mitochondria to a more robust state.  

You need to up your game to “moderate” physical activity to do that.

Moderate physical activity is defined by an elevated heart and breathing rate, which can include walking at a faster pace.  Engaging in moderate physical activity will: (i) enhance the efficiency of your heart and lungs, (ii) improve your VO2 max score (a measure of the body’s ability to efficiently use oxygen during a workout), and (iii) increase your expected life span.

And, it will create new and improved mitochondria, which means more and better fuel for your muscles.

Better yet is running, even if it is a slow run (still considered a ‘moderate’ activity). It’s not just the increased speed. Rather, it’s the requirement to “bound” such that neither foot is touching the ground, just for a split-second, with every stride.  This requires “more force, energy, and power than walking,” according to Dr. Alyssa Olenick, an exercise physiologist and postdoctoral research fellow in the energy metabolism lab at the University of Colorado. When you’re able to dial up your slow-run speed a bit, your moderate physical activity becomes “vigorous” physical activity.

And, no surprise, vigorous physical activity is even better for your mitochondrial health.

How much physical activity is recommended?

U.S. federal health guidelines recommend 75-150 minutes/week of vigorous activity and twice that much for moderate physical activity. In terms of time efficiency, running is a clear winner. But it is more than that: In a 2011 study (“Minimum amount of physical activity for reduced mortality and extended life expectancy” by Wen et al., Lancet, 2011) involving 400,000 older adults, researchers found that regular five-minute runs extended subjects’ life spans as much as regular 15-minute walks did, suggesting a 3X efficiency advantage.  But they also found that regular 25-minute runs and 105-minute walks each resulted in about a 35% reduced risk of dying over the next eight years, suggesting a more-than 4X time-efficiency advantage.

Not to pile on here, but in another study (JACC, 2014), researchers found that regular runners — including those jogging slower than 6 miles per hour — were 30 percent ‘fitter’ than walkers and sedentary people and had a 30% reduced risk of dying over the next 15 years.

How to start a walk-then-run program

Admittedly, running has its downsides. It is relatively high impact, and it can be hard on your connective tissues. Short-term injuries are certainly more common in runners than walkers. 

As such, one needs to ease into any new physical-activity program, so try this progression if you are just starting out with the thought of getting to the ‘run’ stage:

Note: Consider checking with your doctor first, especially if you’re being treated for heart disease (or other chronic condition) or if you have chest pains. Your doctor might recommend a stress test or other evaluation before clearing you to proceed.

Step 1: Increase your walking step count, with an aim of getting to 7,000 steps per day

Step 2: Pick up the pace….SLOWLY.  Aim for 5-minutes of brisk walking 2-3 times per week, increasing that slowly to 10-15 minutes 3-5 times per week.  Add leisurely walking to either end of the brisk walk such that you are on your feet for 30-60 minutes per workout.  You will notice—probably after 4-8 weeks—that you need to walk even faster to reach moderate activity—you’re now ready for Step 3.

Step 3: Add in run-walk intervals. Start with a 5-minute brisk walk. Then mix in one minute of jogging with three minutes of walking. Do this 3-5 times during your workout.  Over time, increase the running and reduce the walking….eventually you will find yourself running continuously, with an aim of getting to at least 20 minutes.

Alternatives for those that choose to not run:  Find a hilly area to walk or a trampoline to jump on.  Check the internet for other routines that include 15-30 minutes of moderate-to-vigorous physical activity. 

And, feel free to mix it up.  Alternate the running thing with other moderate-to-vigorous activities.  Consistency matters, so find a regimen that you like and stick with it!

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Inspired by the New York Times article: “Running vs. Walking: Which Is Better for Lasting Health?” By Cindy Kuzma, published Nov. 14, 2023 and updated Sept. 5, 2024.