On Caffeine

In lieu of the Jillian Michaels Caffeine Pill distribution in the latest season of The Biggest Loser, I thought I would just touch on Coffee, Caffeine and Exercise.

After reading a few research articles about caffeine/coffee and it’s affects on weight loss, energy expenditure and obesity/diabetes, I wanted to summarize what some researchers have found on the world’s most popular drug (and highly delicious one I might add).

The caffeine content in coffee varies depending on how the coffee bean is roasted, along with a few other factors. But for an average cup size, approximately 8 ounces, there is about 100 milligrams of caffeine and the same goes for tea.

Coffee gets absorbed in the stomach and small intestine, and then is eventually metabolised in the liver, that is after many hours post consumption.

Outside of having an effect on the chemicals in your brain (adenosine receptors, dopamine etc), caffeine has been known as a performance enhancer, boosts power output, increases endurance and speed in activities lasting more than 1min and less than 2 hours; so any workout and most sports games. Let’s get this straight, it’s the caffeine, not the coffee itself that has ergogenic effects (Greenburg et al, 2006).

On the potential side effects of caA_small_cup_of_coffeeffeine and its possibility for weight control, caffeine has the potential for thermogenesis. By stimulating the Cori cycle, or simply the cycle of converting lactate to glucose between muscles and the liver, the caffeine can stimulate the use of fat by skeletal muscles as another form of energy expenditure (burning calories!). (Powers & Howley, pp. 66, 2009).

Lipid Metabolism, or the burning of fat, is increased with the consumptions of caffeine. Caffeine has been found to actually reduce adipose-pad size (again, fat!) and fat cells or adipocytes in the body. This leads to a decrease in body fat and an increase in fat metabolism, which is when your body uses the fat instead of storing it in areas that we work so hard to get rid of… some we way muffin top?

Lipolysis is the breakdown of fat into free fatty acids (FFA), glycerol and triglycerides. FFAs are stored as triglycerides, and triglycerides and glycerol like to be stored in fat cells (along with other cells in the body), but caffeine tends to prevent some of this extra storage in fat cells. Instead it helps shuttle the fat to skeletal muscles and other tissues to be used as energy. (Powers & Howley, pp. 31, 2009).

All of this sounds great, except the above mechanisms are really only effective in non-obese people. Obese people tend to have a “lower sensitivity to lipolytic stimuli” (Greenburg et al, 2006) and so being non-obese will see greater benefit in adding caffeine.

Now back to the reason why I think Jillian Michaels supplementing her team with caffeine pills isn’t horrible (although, without the show’s doctors being aware of this, there is always potential for other health risks to arise, including increased blood pressure and heart rate. But I’m not going to get into that. Just saying, she probably should have let the professionals know so they could have been prepared if anything happened). Caffeine has been shown to stimulate a higher rate of physical activity! Essentially it gets you off your butt and moving! How bad can that be? It’s been shown to increase motor activity, and improve exercise performance.

Why do you think pre-workout drinks have caffeine in them? To help you train, play or exercise more efficiently! As I said before, it improves power output, increases endurance and improves performance!

I don’t see caffeine as bad thing when it comes to training. It might not be essential to supplement everyday, but it can add that extra “Umph” to your workouts. And if you feel amped to train then you’re going to get more out of your workouts and therefore see more results and maybe see them faster than if you hadn’t added used caffeine.

If you’re going to supplement with caffeine, studies suggest that for fat loss 15mg/kg of body weight is adequate. As well, there are levels of tolerance. Someone who drinks 4 cups of coffee a day may not see or feel that same results as someone who abstains from caffeine for a few days at a time then supplements. For exercise performance 100-200mg of caffeine can help decrease drowsiness and increase alertness, which may help get you through those horrendous leg days. (Powers & Howley, pp. 545, 2009).

With supplementing caffeine, there are those potential side effects. These include insomnia, diarrhea, anxiety, irritability and sometimes shakiness. Caffeine can also have a diuretic effect, but with proper hydration should not pose any problems.

If you want to add that extra boost of energy to your workouts, try caffeine. If you understand the side effects and know your health/heart and you’re confident you are healthy enough, give it a shot, unless you’re a contestant on The Biggest Loser and then you might be breaking some rules.

Happy Training!


Greeburg, J.A, Boozer, C.N. & Gliebter, A. (2006). Coffee, diabetes, and weight control. The American Journal of Clinical Nutrition, 84;682-93.
Retrieved from: http://ajcn.nutrition.org/content/84/4/682.full.pdf

Powers, S.K. & Howley, E.T. (2009). Exercise Metabolism. In Ryan, M. (7th edition), Exercise Physiology: Theory and application to fitness and performance (pp. 66).

Powers, S.K. & Howley, E.T. (2009). Ergogenic Aids. In Ryan, M. (7th edition), Exercise Physiology: Theory and application to fitness and performance (pp. 545-546).

What is it about Coffee? (2012, Jauary). Harvard Health Publications.
Retrieved from: http://www.health.harvard.edu/newsletters/Harvard_Health_Letter/2012/January/what-is-it-about-coffee

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