Why should I not just run as hard as I can for 30 mins instead of jogging for an hour?
If you jog you burn fat more efficiently, meaning more of your efforts are fueled by fat. Less intense exercise uses a higher % of fat in the body for fuel than carbohydrates in the body, meaning your body will use fat instead of the sugar in your system.
For most of us lol fat is the most abundant fuel source in the body, and is therefore a great choice for the body during long duration exercise or running.
But, fat is harder to access as fuel when the heart rate is high like when running so your body uses sugar and muscle because it is easier to break down for fuel. So when you go hard on a run your body will most likely burn carbs as its fuel source.
This is why runners drink Vitargo or eat the high glycemic (fast digesting sugar) before and during their runs, it is used as fuel instead of fat and muscle.
An example being, if you go running hard for an hour you will burn more calories in total but less calories from fat than you would if you just jogged for an hour jumping on the line of fat burning and sugar burning.
The heart rate monitor watch helps you do that successfully.
Check out the next David Kimmerle heart rate monitor training tip Unmotivated Gym Session~ Maybe It Is Pussitis?