Increase Training Density to Simultaneously Burn Fat and Build Muscle
I'm a regular reader of your blog and first of all, I have to say, you do a great job with it.
I'd just like to pick up on a couple of things you said in response to a recent post about the type of training someone should be doing as a skinny-fat guy.
You recommended dropping jogging as it raises cortisol levels, cutting out carbs as much as possible and using weight training to simultaneously gain muscle and lose fat.
How do shorter (20 minute) HIIT running sessions affect cortisol levels? I wouldn't like to cut cardio out of my training to be honest, as I like the way it makes me feel. I'm interested in having a good level of cardiovascular fitness as well as muscular strength.
Is it really possible to gain muscle AND lose fat at the same time? Many say it's either one or the other and to gain muscle you need a calorie surplus while to lose fat you need a calorie deficit. The two are therefore mutually exclusive goals.
Also, how serious are high cortisol levels and can anything be done to get them down to normal levels for guys like me?
Many thanks for your time.
My Answer: Perfectly fine to keep HIIT as cardio. In reality, all types of training release cortisol. It just depends how much cortisol in relation to testosterone, growth hormone and other anabolic hormones such as IGF and FGF. Negatives, for example, cause extreme stress and damage to your muscles and as a result, a high amount of cortisol is released. BUT localized hormones such as IGF and FGF are released as well, which is why people grow (initially) on eccentric training.
Steady state cardio, however, releases a ton of cortisol, but not much of anything as far as testosterone, the king of all anabolic hormones. If anything, you will deplete your T-levels to virtually zero, which is why endurance athletes such as cyclists and marathon runners benefit greatly from steroids.
HIIT for 20 minutes is different, because it resembles strength training. Sprint for 10-20 seconds then walk for a minute. That's like doing an intense set of high rep lunges, then resting. You are doing more work per unit of time, and this is the key to simultaneously building muscle while burning fat.
Same thing goes for strength training: increase the density of training (more reps, more sets, shorter rest periods) and you can simultaneously build a bigger engine (muscle) to burn fuel (fat). In my experience, however, people who have the easiest time burning fat while building muscle are endomorphs. Ectomorphs will find it extremely difficult and frustrating serving two masters.