Ask for: Donuts Coffee [walking time] [treadmill]
You seem to know a bit about sports, so I thought you might be able to answer a question for me on the treadmill. Right now I do about 45 minutes at 3.5 mph (approximately 2 miles). Would it help burn more fat lengthen my time walking, or on a slope to add? Do you happen to know?
Reply:Thank you so much, you really cleared up alot of my questions. I REALLY appreciate it!
Reply:so donuts, if i'm doing high intensity for 30 mins…is it basically the same as low for 1 hour…(give or take)?
thank you for this info…always wondered about it! 
Reply:Originally posted by guy:
You seem to know quite a bit about exercise so I thought you might be able to answer a question for me in regards to the treadmill. Right now I do about 45 minutes at 3.5 mph (about 2 miles). Would it help burn more fat to lengthen my walking time, or to add an incline? Do you happen to know?
guy,
There are two kinds of cardiovascular exercise, low intensity and high intensity. Low intensity cardio is where your heart rate is 75% of its maximum. High intensity is where it's 85% or higher. To figure out your maximum heart rate, subtract your age from 220. Focus on your heart rate instead of your speed or incline.
Low intensity cardio will burn stored fat during your workout. However, this only happens if your blood sugar is low and your muscle glycogen (stored sugar) has been depleted. This is why doing cardio first thing in the morning is ideal. Some people don't like to get up early so they do cardio right after a weight training session. The thinking there is that the weight training will use up muscle glycogen and lower your blood sugar so that if you do low intensity cardio right afterwards, your body will have no choice but to burn stored fat.
High intensity cardio will not burn fat during the workout. It will use glucose instead. But as soon as you're done, the body will suddenly release a lot of stored fat into the bloodstream and your body will burn that, provided you don't eat anything for 30-60 minutes.
When it comes to cardio, I would focus more on when you do it, the duration, and the intensity and not so much on how much fat you may be burning cause over time your body will get more efficient at the same workout and burn less fat. The real value of cardio is in its impact on your metabolism. Whenever you exercise, your body releases adrenaline and noradrenaline, which both help burn fat even after you're done working out. If you do 45 minutes of light cardio, your metabolism will be elevated for 3 hours and if you did 60 minutes, it would be elevated for 7 hours. Just don't exceed 60 minutes cause then your body will think you're in a crisis and not want to burn fat. If you do high intensity cardio, the impact on your metabolism gets even better because more noradrenaline gets released. The metabolism could stay elevated for as much as 12 hours. And because it's more intense, your exercise session doesn't have to be as long as it would if you were doing low intensity.
