The Truth About Caffeine and Running

A few years ago I tried my first cup of coffee before a race, and I haven’t looked back since.

By now you’ve heard about caffeine’s widely heralded positive effect on running performance.  If you’re still in the skeptical crowd or worried about its potential negative effects, I don’t blame you.  Runners know there’s no shortcut to success, so when a “cheat code” like “the other Vitamin C” comes along, things seem a little, well, too good to be true.

I’m here to confirm for you, once and for all, the truth about using caffeine around running. Used in the right amounts and at the right times, caffeine can definitely boost your performance in a safe and reliable way.

Of course, there are right and wrong ways to use it, so read on to find out how you can responsibly make caffeine benefit your workouts, races, and recovery.

The benefits of caffeine

Everyone who’s ever had a cup of coffee or an energy drink knows that caffeine promotes wakefulness, alertness, and improved mood.  At the most basic level, caffeine can help you get out the door for a run in the morning when you’d otherwise feel groggy and inert.  What you may not know is that caffeine alters the chemical processes in your nervous system, muscles, and bloodstream, changing several important factors that directly influence running.

Caffeine reduces a runner’s level of perceived exertion, meaning that the same running pace can be maintained with less psychological effort.  Caffeine acts as a nervous system stimulant, changing your perception of pain and muscle discomfort.  One meta-analysis study found that subject’s rating of perceived exertion (RPE) decreased by 5.6% during exercise after ingesting caffeine.  Read: that’s more than a minute benefit over 5k at seven minute pace!

In addition to changing how you feel about what’s going on in your muscles, caffeine actually positively impacts muscles themselves by increasing calcium ion release.  This is one of the major mechanisms of muscle contraction.  That cup of coffee helps you physically run harder and at a reduced effort.

If that isn’t good enough news, caffeine also increases the body’s ability to burn fat by increasing the circulation of free fatty acids in the bloodstream.   Usually muscle glycogen is the first energy store your muscles use.   With caffeine, you end up converting fat into energy at a higher rate, lowering the rate of glycogen burn. This effect potentially increases endurance by extending your body’s energy stores.  Fat burn is of course good news for runners trying to lose weight.

Caffeine has a pretty cool effect on post exercise recovery too.  After you run, your body uses carbohydrates to make glycogen, a fuel store.  Caffeine has been shown to increase the rate of  glycogen resynthesis by a whopping 66% in the four hour period after performing exercise to exhaustion.  This means the carbs you eat after working out go to work faster and more effectively in the presence of caffeine.

So how should I use caffeine?

Research has shown that caffeine’s positive effects on exercise peak 3-4 hours after consumption, and are very strong within an hour.  Aim to ingest caffeine about an hour before your workout or race.  Because caffeine’s effects last hours, you can get both the workout and recovery benefits from the same cup of coffee.  One thing to keep in mind, especially if you use caffeine prior to a race, is bathroom timing!

How much?  Most caffeine studies use between 6 and 8 mg caffeine per kilogram body weight.  That’s a lot.  One medium (16oz) cup of drip coffee is sufficient to get the all the runner’s benefits of caffeine.  Don’t worry if you’re a regular coffee drinker.  You still get the performance and recovery benefits of caffeine if you consume a moderate amount of coffee on average.

In what form?  Coffee is the most popular vehicle for caffeine, but for some runners, it can cause stomach issues.  If you want to use coffee before running, wean yourself on with smaller amounts at first, and remember to hydrate concurrently.  Skip the fancy, sugar laden concoctions – you’re about to run and don’t need the junky sugars.  Fructose (a sugar) has been shown to reduce the good free fatty acid response to caffeine.  For those reasons I don’t recommend getting your caffeine fix from energy drinks or soda.

Caffeine pills are a good alternative to coffee.  Many elite runners take a caffeine pill before competition.  Black and green tea provide a smaller dose.  You can also try energy and recovery products with added caffeine like energy gels, chomps, and RunGum.

Caffeine sounds pretty great for runners.

So what gives?

There’s always another side to the story.  Caffeine allows you to stress your body more.   For that very same reason, it needs to be wielded responsibly.

One drawback of caffeine use for running performance is dependence.  You might find yourself feeling the need to use caffeine to get through workouts.  Without the decreased perceived exertion and muscle performance benefits of caffeine, you could feel stale without it.

This isn’t necessarily a bad thing if you monitor your efforts wisely and know when to back off from.  Try using different amounts of caffeine depending on the situation.  For an easy day, no caffeine at all, or a cup of black tea might do the trick; for a race, a coffee.

Caffeine is a diuretic.  However, studies have shown that exercise mostly counteracts the dehydrating effect of caffeine.  As for fears that caffeine leaches Calcium and contributes to osteoporosis, no conclusive evidence has been found to support them.

There is evidence that caffeine use during exercise can weaken a part of your immune system.  Running guru Steve Magness points to a study that found cells called antigen-stimulated T-cells are decreased when exercise and caffeine are combined. This potentially hurts your immune system’s ability to respond to disease.  However, hard training itself temporarily weakens the immune system.  It’s not clear if caffeine or the increased performance ability it causes is responsible for the effect.

The Bottom Line

There’s no longer any question that caffeine improves running performance and recovery.  Caffeine itself doesn’t stress your body; the increased training load it allows does.  If you’re looking to feel better and run faster at your next race, drinking a cup of joe beforehand is worth trying.

Sources:

[1]https://www.ncbi.nlm.nih.gov/pubmed/15773860

[2]http://maxwellsci.com/print/crjbs/v3-521-525.pdf

[3]http://www.sciencedirect.com/science/article/pii/0026049568900541

[4]https://www.ncbi.nlm.nih.gov/pubmed/18467543

[5]http://www.sciencedirect.com/science/article/pii/0026049568900541

[6] http://running.competitor.com/2014/06/nutrition/do-the-performance-benefits-of-caffeine-come-at-a-cost_49856