Proteins, Carbs, Fats and the Boogeyman

What are your goals?

You need to figure out what exactly you want to accomplish before starting a diet or exercise program.

If you want to run a marathon down the road, logically you can only get good at running by running, and you’ll have to do a lot of it. Subsequently, your carbohydrate needs are going to be vastly more than the average person.

Extreme aerobic type workouts, i.e. running for miles at a time for hours at a time, are going to burn through your dietary intake of carbs and muscle glycogen stores, there’s no getting around that.

It’s not an optimal environment for adding lean body mass, though, so if you want to look and train like a strength athlete, long endurance running is counterproductive. It’s like digging a ditch, and the deeper you dig into your muscle glycogen stores, the harder it is to refill and build them higher, which is essentially what you want your muscles to do when you’re a strength athlete.

On the other end of the scale is too much carbohydrate consumption without the activity levels to compensate for said activity. When muscle glycogen stores are filled, the carbohydrate being consumed has no place to go. Chronically elevated insulin levels suppress fat burning, with the conversion of excess carbohydrate into fat.

If you train like a bodybuilder, lift weights in the gym and do a little conditioning work, there is no need to be consuming carbohydrates in large quantities throughout the day. I find, and this is just my experience, restricting carbs at non-active times of the day leads to improved ‘sensitivity’ to carbs when I do eat them when they’re needed most, following an intense workout. All the literature I’ve come across suggests consuming a good carbohydrate/protein supplement immediately post exercise for maximum recovery and muscle protein synthesis (i.e. muscle growth). In the same way that carbohydrate and protein work synergistically to increase muscle glycogen storage, they also work together to increase muscle development and strength. But they can also put you in a coma and lead to diminished performance if you’re over-eating. That’s why I’m opposed to a big hearty breakfast before an eight hour shift at a computer each work day. There’s no need. Save that for dinner after an early evening workout!

One final point. Eating NO carbs and relying solely on protein and fat is not an ideal environment from a health or muscle building perspective either. That’s the other extreme.  When carbohydrate is severely restricted, blood glucose must be maintained by producing glucose via gluconeogenesis. Gluconeogenesis is activated by the hormone cortisol. Aside from activating gluconeogenesis, cortisol also activates muscle tissue breakdown in order to provide the amino acids that are used to produce the glucose. It also reduces the functionality of the immune system. For someone living a largely sedentary existence, limiting or replacing carbs entirely with healthy sources of dietary fat can be an effective weight loss strategy in spurts, but I don’t think it’s a long term plan for success. Eventually you’ll rebound and crave carbs that much more.

Light bulb moment: Balance is the key here!


Mitch Calvert is a Winnipeg-based fitness coach for men and women like his former self. Heavyset in his 20s, he lost 60 pounds and now helps clients find their spark and lose the weight for life.