I can't really run because of a knee injury but I think instead of walking an hour a day I'd like to try HIIT walking.  It sounds like it saves time and is more beneficial.  
Can it be done on a treadmill alternating between intense walking for 2 minutes and low for 1 minute?
Also if I'm used to walking at moderate speed for 1 hour, what time frame should I give myself for HIIT walking? A half hour? 20 Minutes?
Thanks-Ken
				
			Can it be done on a treadmill alternating between intense walking for 2 minutes and low for 1 minute?
Also if I'm used to walking at moderate speed for 1 hour, what time frame should I give myself for HIIT walking? A half hour? 20 Minutes?
Thanks-Ken
 
						 
 
		 
 
		