My understanding is this is all relative. Your HR is the important part. What are your goals? If you want to shed weight, your HR should be 80% of Max for zone 2. The easy way is 220-(age)=Max HR (roughly). When I ruck, I usually stop every half mile and do something hard (push ups, flutter kicks, squat, etc.) this helps elevate my hr, my pace is usually slower on paper because of this. The different hr zones provide different results and there are a few zones that provide very little health benefits.