Q&A with Dr. Fogarty: The straight dope on adding stimulants to your workout



Spinaca Farms: When you talk about increasing endurance for workouts, what is the difference between using a stimulant like caffeine or some other pre-workout type supplement vs. eating foods high in dietary nitrates and getting plenty of rest? Are the different techniques to increase endurance triggering different reactions in the body to produce energy?

Dr. Fogarty: For pre-workout, caffeine works a bit differently from nitrates. They both activate the adrenaline pathways which lead to increased heart rate and increased central nervous system activity so we can recruit more muscle fibres per-contraction (sort of). They both also help to breakdown fat stores quicker. Fat produces more energy per gram than carbohydrates but the oxygen cost of burning it is higher because its a bigger molecule. When we need energy quickly carbohydrates give us a good clean energy supply with less oxygen debt but caffeine helps to offset this so we can keep our carb-stores for later in the race.

Nitrates are thought to work better by increasing blood flow to our skeletal muscle bed, so the vessels that carry the oxygenated blood to our working muscle groups become physically wider so we get more air in. More air in equals a hotter fire. Theoretically, this suggests our endurance capacity is increased because we can run at a higher pace for longer before fatiguing.

In that sense, the two different methods are very different.

Note: Pre-workout supplements tend to have an amino acid called beta-alanine in it. In high doses that amino acid gives you the shakes or the jitters. This gives you a bit of a placebo effect that you’re bursting with energy ready to get after it. Rather than a pre-work drink, have an espresso and then take 3g of creatine. 

Spinaca Farms: What are the long term effects on the endocrine system by using ephedra or Ma Huang for extended periods of time? I know these items were removed from the marketplace in the mid-2000s but curious—I have a friend that wants to know ;).

Dr. Fogarty: I think the fact these things are no longer on the market probably says a lot more about their safe use than anything I could say. However, the simple principle of using this type of product (or anything else that claims to naturally increase testosterone production) is that if you stimulate the endocrine system constantly artificially you can burn it out so it stops or slows down the natural production of the hormones is normally makes. 

Short-term use can have a positive effect for sure but I think it’s perhaps not worth the long-term risk. Exercise is the best natural stimulus of the endocrine system that I know of, as long as you listen to your body when it says rest as opposed to just being a bit sore from the efforts. 

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