Alex Cook - EXALT Sports and Endurance Dietitian
CAFFEINE & PERFORMANCE
Most of us live for our morning coffee. Caffeine helps us feel alert and temporarily reduce tiredness. If consumed in low to moderate amounts there are minimal health consequences and only those sensitive to caffeine suffer short term side effects such as insomnia, headaches or nausea. It is highly individual though and tolerance levels vary between individuals.
WHAT IS CAFFEINE?
Caffeine is naturally found in over 60 plants species, commonly coffee beans, tea leaves and kola nuts. When consumed, caffeine is rapidly absorbed through the gut, circulated to the tissues and broken down in the liver. It is also rapidly absorbed into the brain. Elevated levels can appear in the bloodstream within 15 - 45 minutes, peaking after about one hour.
Scientific research looking into caffeine’s effect on submaximal, prolonged exercise is extensive. One of the earliest studies showed that after consuming of 330mg of caffeine 60 minutes prior to exercise, elite cyclists increased their time to exhaustion from 75min (placebo) to 96min (caffeine) (Costill et al 1978). However, benefits are not just seen in endurance exercise, improvements have also been seen in shorter bouts of maximal efforts (all-out effort) exercise.
HOW DOES CAFFEINE WORK?
Multiple mechanisms have been suggested as to how caffeine improves performance. The most cited theory suggests that it improves performance in early exercise as a result of increased fat oxidation and the sparing effect it has on our carbohydrate stores, increasing time to exhaustion during exercise. However, alteration in muscle metabolism alone cannot fully explain the beneficial effect of caffeine on exercise.
Other theories have been suggested such as a direct effect on the nervous system affecting perception levels (reducing the perception of effort) and also potential direct effects on the skeletal muscle. However, as with any research, there are still areas of conflict and the exact mechanisms to its success are still unclear.
HOW MUCH CAFFEINE DO YOU NEED?
Various studies have set out to identify the levels of caffeine needed to improve performance. Most trained individuals seem to benefit from a moderate dose of 5mg per kilogram of body weight (mg/kg) but intakes as low as 2-3 mg/kg have been found to enhance performance. For a person weighing 70kg this would be an intake of between 140-350mg of caffeine before exercise to see potential improvements in performance. In real terms, this would be approximately 1-3 cups of 250ml fresh filter coffee. However, it must be remembered that there is an individual response to caffeine and even lower doses than the science states can see some benefit.
EXALT "Higher Energy" packs a larger caffeine punch at 100mg of caffeine from our natural energy and immunity blend (made from natural coffee extract, guarana seed extract (22% caffeine) and kola nut extract (20% caffeine).
CAFFEINE VS COFFEE: WHAT'S THE DIFFERENCE?
Most of these studies focus on caffeine but does coffee have the same effect? A study done in 2013 looked at the effects of caffeine and coffee on trained cyclists performing a 45 minute time trial (Hodgson et al 2013). One hour prior to exercise, the athletes consumed either a drink containing: caffeine, instant coffee, instant decaf coffee or a placebo. The main outcome was that both the caffeine and coffee time trial times were significantly faster compared to the decaf and placebo. The findings in this study are in line with other studies demonstrating that coffee is not inferior to pure caffeine in improving endurance performance.
This is great news for coffee lovers but the caffeine content of coffee can vary hugely through strength and amount consumed. This makes it hard to know just how much caffeine you are having due to the variable levels in a drink. If you want to know exactly how much caffeine you are consuming or if you are caffeine sensitive, it is best to stick to the same coffee brand. Alternatively, if you want a caffeine hit when out and about and are unsure of the caffeine content of a product, having drinks with a measured amount of caffeine for example; Type A (80mg) or Firestarter (100mg) is a good alternative.
DOES CAFFEINE DEHYDRATE YOU?
If you choose to drink coffee or tea before exercise, a common misconception is that this will contribute to dehydration. In fact, a cup of coffee can count towards your daily fluid intake. A study performed in 2014 proved that there was no evidence of dehydration with a moderate daily coffee intake (Killer at al 2014). The effects of coffee consumption (800 ml of coffee containing 4mg/kg caffeine, ) versus water were compared on 50 males. No differences were observed in the blood and urinary markers used to measure hydration levels, indicating that, if consumed in moderation, caffeine provides similar hydrating qualities to water.
CAN CAFFEINE HELP EXERCISE PERFORMANCE?
Despite these wonderful stats, caffeine intake around exercise is not the golden bullet for all. We all know somebody who can drink espresso late at nighttime with no effect on sleep and others that have to stop drinking caffeine after lunch due to sensitivity.
How caffeine affects those during exercise is also very individual. Not everyone will see these performance benefits. Various factors exist behind this fact. The speed at which caffeine is absorbed is one. For example, if you are drinking coffee on a full stomach, the rate at which the caffeine is absorbed will slow down. Even the way in which we metabolise the caffeine is highly individual, and some will break it down much slower than others. Recent findings have also suggested our genetic make up may have an effect on how our bodies respond to caffeine intake.
TOP TIPS FOR CAFFEINE & PERFORMANCE
- If consumed in moderation, coffee can be part of a healthy lifestyle and balanced diet.
- Tolerance levels vary between individuals.
- Caffeine has been found to increase endurance performance if taken an hour before the start of exercise.
- Regular intake of fruit, vegetables and salads (try for at least five-a-day, seven is even better if you can). If you think you will struggle with this consider taking a multivitamin.In trained individuals, consumption of 2-5mg/kg has been found to be most beneficial, over that amount has not been found to further improve performance.
- Coffee is as effective as caffeine in improving performance although levels vary widely between drinks.
- Caffeine in moderation does not affect hydration. It can count towards your daily fluid requirement.
- No amount of caffeine will compensate for an unbalanced diet. If you are using caffeine to boost performance, make sure you are also fueling adequately with a good diet.
References
1. Costill DL, Dalsky GP, Fink WJ. Effects of caffeine ingestion on metabolism and exercise performance.Sci Sports. 1978 Fall;10(3):155-8.
2. Hodgson AB, Randell RK, Jeukendrup AE The metabolic and performance effects of caffeine compared to coffee during endurance exercise. PLoS One. 2013;8(4)
3. Killer SC, Blannin AK, Jeukendrup AE No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population PLoS One. 2014 Jan 9;9(1)