Running vs walking: what each one does for your body
At the same energy cost the health returns are close. Bone, aerobic ceiling, and time are where they part.
For most disease risk, the energy is what counts
Two long-running cohorts gave researchers something rare: 33,060 runners and 15,945 walkers, measured the same way, followed for 6.2 years. The comparison was made at equivalent energy expenditure, so a long walk was set against a shorter run that cost the same. [1]
Per unit of energy expended, running lowered the risk of incident high blood pressure by 4.2 percent, high cholesterol by 4.3 percent, diabetes by 12.1 percent, and coronary heart disease by 4.5 percent. Walking lowered the same four by 7.2, 7.0, 12.3, and 9.3 percent. [1]
Look at those two rows again. Walking is not the lesser version of running. Matched for energy, walking came out at least even on all four, and the authors concluded that moderate and vigorous exercise produced similar risk reductions. [1]
That is the single most useful finding for anybody starting from nothing. The energy is what counts, and you can spend it at whatever intensity you can sustain.
Where running is genuinely different: bone
Bone remodels in response to the size of the load it takes, not the number of minutes it spends taking it. Which makes force, not duration, the variable that matters here.
Measured across a range of speeds, the peak vertical ground reaction force in walking runs from about 1.0 to 1.5 times body weight. In running it rises to about 2.0 to 2.9 times. [3]
That gap is the whole story. Impact at running magnitudes puts strain through bone at levels that trigger remodeling. Walking, for most people at most speeds, sits below the level where that signal fires strongly.
It matters more the older you are. It matters more again if you are a woman past menopause, because that is when bone loss accelerates and the list of things that slow it down which also fit inside a lunch break is short.
Where running is genuinely different: your aerobic ceiling
VO2 max responds to intensity more than to duration. You can raise it by walking, particularly from a sedentary start and particularly uphill, but running reaches the intensity range that moves it fastest.
That number is worth moving. It is the one with a mortality dose-response behind it, measured across 122,007 adults with no observed upper limit of benefit.
Where running is genuinely different: time
Equivalent energy expenditure is the fair comparison scientifically. It is not always the fair comparison practically, because covering the same energy on foot at walking pace takes roughly twice as long.
If you have forty minutes, walking and running are close to even. If you have twenty, they are not.
One more difference worth naming honestly. Over the same 6.2 years, change in body mass index was more strongly related to change in running than to change in walking, in men and in heavier women. [2] If weight is the thing you are after, the research does separate them.
So which should you actually do
That is a different question from what each one does to you, and it has a different answer, because accessibility beats optimality for anybody who is not already exercising.
Common questions
Is walking as good as running?
For high blood pressure, high cholesterol, diabetes, and coronary heart disease risk, matched for energy expended, the research says close to yes. Running separates itself on bone loading, on how fast it raises aerobic capacity, and on how long it takes.
Does walking build bone density like running does?
Less. Peak ground reaction force in walking is about 1.0 to 1.5 times body weight against about 2.0 to 2.9 in running, and bone remodels in response to the size of the load. Walking sits below the level where that signal fires strongly for most people.
Does running or walking burn more calories?
Running burns more per minute. Per mile the two are closer than most people expect. The research comparisons that matter are made at equal total energy expenditure, which is why a long walk can match a short run.
References
- Williams PT, Thompson PD. Walking Versus Running for Hypertension, Cholesterol, and Diabetes Mellitus Risk Reduction. Arteriosclerosis, Thrombosis, and Vascular Biology 33(5):1085-1091, 2013.
- Williams PT. Greater Weight Loss from Running than Walking during a 6.2-yr Prospective Follow-up. Medicine & Science in Sports & Exercise 45(4):706-713, 2013.
- Nilsson J, Thorstensson A. Ground reaction forces at different speeds of human walking and running. Acta Physiologica Scandinavica 136(2):217-227, 1989.