What are the benefits of running instead of walking?

Running will vastly improve your cardiovascular system and give you greater endurance. Walking is lower impact, but walking at a brisk pace is a pretty decent workout. Surprisingly, if you look at professional body builders, most do not run, but walk as their cardio to burn off excess calories without sacrificing muscle.

It depends on your goal. If overall fitness is your goal, there's not much that can beat running. If you want to buid muscle and already have a lower body fat percentage, walk.

I think the main issue is intensity and duration. You can do a higher intensity activity for a shorter time to get the same benefit of a moderate intensity activity for a longer time.


MET (Metabolic Equivalent): The ratio of the work metabolic rate to the resting metabolic rate. One MET is defined as 1 kcal/kg/hour and is roughly equivalent to the energy cost of sitting quietly. A MET also is defined as oxygen uptake in ml/kg/min with one MET equal to the oxygen cost of sitting quietly, equivalent to 3.5 ml/kg/min.

Probably easiest to look at a chart of Metabolic equivalents: http://en.wikipedia.org/wiki/Metabolic_equivalent
"Since MET is a measure of intensity and rate, the concept of MET-minute can be used to quantify the total amount of physical activity in a way comparable across different persons and types of activities. Thus brisk walking at 5 km/h for half an hour (a moderate intensity activity of 3.3 MET) accounts for about 100 MET-min and is in this aspect equivalent to running at 10 km/h for ten minutes (a vigorous intensity activity of 10 MET). This way the total effort expended in different activities over a period of time can be accumulated: health benefits of physical activity increase with increasing levels of activity and do not plateau until quite high levels."

So Walking (3.3 METS) x 30 min=99 MET-min
Running (10 METS) x 10 minutes=100 MET-Min.

So then your choice should be based on what you can do safely (you may not have the endurance to maintain a high intensity for the needed period of time, but can do a lower intensity exercise without crushing substernal chest pain or having both of your knees swell), what like to do and thus will stick to, how much "burn per minute" you want to get once the first two criteria have been addressed.