I had a bit of a crazy week of study last week. Had my last BioChem exam on Thursday and all I was getting done was study. I put a little update post up on Saturday covering a few changes and teasing an upcoming feature of the site, so if you missed that hit the link.
While I was going back over all of my notes and going back through my textbook, General, Organic and Biological Chemistry by H. Steven Stoker, to find some good points for my exam extended questions. I came across a little off topic section they refer to as "Chemical Connections" and this particular one was talking about the difference between 'High Intensity Training' and 'Low Intensity Training'. It points out some very interesting numbers.
- In a resting state the human body burns more fat than carbohydrates
- The body requires on average, 1.0L of oxygen to burn 1g of fat and 0.7L of oxygen to burn 1g of carbohydrates
- Beyond an hour of training, triacylglycerol use may be as high as 80%
Stoker explains that when we start training our primary energy source is glucose due to a shortness of breath and reduced oxygen availability. But as the workout continues we see an increase in oxygen and the rate that we can convert lipids to ATP increases also.
So what does this mean?
To burn a total of 300 calories 'Low Intensity Exercise' requires 48 minutes and on average will consume 133 calories of fat. Compare that to 'High Intensity Exercise' (I'm not referring to 'HIIT' by the way, I'm talking about hitting a treadmill for hours at a time. HIIT is a whole different kettle of fish) which over 30 minutes will only consume 65 calories of fat and again, a total of 300 calories. So with an extra 18 minutes of exercise you can get more than double of the calories you're trying to target, without adding extra carbohydrates into your diet (intense cardio with low carbs, more than likely will jack up cortisol levels, which is another story for another day). Or, we can look at this as. In the same time frame, lets say 1 hour, you'll burn twice as much fat with low intensity training than an hour of high intensity training. Of course this isn't exactly new information, but it does make me consider why running is so broadly thought of being so good for weight loss and weight lifting is seen in a negative light. Maybe its because we see heavy weight power and Olympic lifters and strongmen, generally looking overweight and long distance runners who look "healthy"
So looking at this information, it may be of some use to us to consider that consuming high nutrient density foods that are lower in carbohydrates, lifting heavy weights and walking is a more efficient way to loose weight (reduce body fat) than running for hours on end. It'll make you stronger, develop good dense muscle (ladies, this WILL NOT make you bulky, you need high amounts of testosterone to get those kind of results), that will give you a faster metabolism and in turn cause you to burn fat more efficiently. Yes, 'High Intensity Training' has its place, but should not be for a weight loss situation. Take your workouts slow and make sure you breath properly throughout. Get as much oxygen as you can, this will help you continue burning fat. Always remember that if you're on a journey for weight loss, you're doing it for you, so you may as well take your time and enjoy it.