I am sure you have read or heard that running will naturally offer greater cardiovascular benefits for the body compared to walking. This is mainly due to the required increase in workrate of the heart to sustain the more intense acivity of running. This greater intensity demands a faster blood flow - good for moving oxygen around the body. This intensity also offers numerous benefits for the heart itself and the overall strength and fitness of the body.
We have written previously about the merits of running - Is Running The Best Exercise For Fitness
A critical consideration is the additional time and effort required to participate in a run versus a walk and whether this extra effort actually causes no activity to be taken.
If we consider that a 5min run could offer the same health benefits of a 15min walk then we would of course believe running to be more efficient and therefore the better exercise of the two.
But what about the additional preparation time around the run? The increased intensity will require a change of clothes before and after and possibly include a shower. You may need time to stretch and cool down after the run too. So your 5 minute run suddenly became a 30min activity. Will this time and effort cause some people to limit the number of times they commit to such an activity? Or perhaps a lack of changerooms and a shower at work means you cannot do this at lunch break?
If the preparations for the run is an obstacle which prevents the activity taking place then it is certainly not a more efficient exercise than walking.
Now consider that 15min walk. It is unlikely a change of clothes or a shower would be needed, neither a stretching session to cool down. This 15min exercise could be performed each and every day at a lunch break.
So the point here is that maybe the best exercise is the one that you will actually show up for and do, regularly. Three or four 15min walks each week will likely be better for your overall health than a single 5min run in your week.
On that note, I have a 15min walk ahead of me to reach a meeting with a fantastic group of people.
Take care and enjoy your walking.