Caffeine is a substance that occurs naturally in the stems, leaves, fruit and seeds of more than 60 plants, including cacao pods, coffee seeds and tea leaves. Caffeine is also made artificially and added to many food items and beverages. Large numbers of medications also have caffeine in them.
The U.S Food and Drug Administration estimates that around 90 per cent of the world’s population consumes caffeine in some form, many of them without realizing that it effects our bodies in a variety of ways.
What are the Effects of Caffeine on the Body?
Caffeine is a drug that stimulates the central nervous system and aids in enhancing focus and concentration. Caffeine’s stimulating effects start taking effect as quickly as fifteen minutes after ingesting caffeine and can last for as long as six hours.
Caffeine makes the stomach release more acid, which may cause a side effect like heartburn or upset the stomach. Within two hours the levels of caffeine reach their maximum in the bloodstream. Here they elevate blood pressure for a short period of time. For most people this is not an issue as there is no long term effect (1).
While circulating in the bloodstream, it can cross into the placenta in pregnant women, where it could increase the baby’s heart rate. So, pregnant women are advised to limit their intake of coffee/caffeine. Excessive amounts of caffeine can hinder calcium absorption and metabolism thus contributing to osteoporosis and muscle twitches.
Caffeine and Weight Training
Many athletes firmly stand by their belief that coffee enhances their physical and mental performance and now there are a large number of good studies supporting this. Caffeine is an ergogenic, meaning it helps individuals improve their use, production and recovery of energy.
Studies conclude that caffeine improves performance by roughly twelve per cent in endurance sports like weight training, where stamina needs to be maintained for longer periods of time. It has also been found that caffeine has little effect on high intensity activities of short durations like sprinting.
The purpose of weight training is to build muscle power and strength. In one 2008 study conducted by K. Woolf, W.K. Bidwell and A.G. Carlsen and published in ‘International Journal of Sports Nutrition and Exercise Metabolism’ caffeines effect on intensity of training and power was investigated.
Take a High Dose of Caffeine and You Will Lift Heavier Weights
Participants given caffeine or placebo were asked to carry out leg and chest presses in addition to the maximal anaerobic test called Wingate. Subjects with caffeine in their systems lifted more weight during chest press and had longer time before reaching fatigue in the Wingate test.
There are three main theories that have been put forth explaining how caffeine works to improve athletic performance. The first theory states that the body burns more fat and less carbohydrates. Muscles primarily use glycogen as fuel, while fat is available is much larger supplies.
When caffeine enters the body, it makes the body use the maximum amounts of fat which delays the exhaustion of glycogen. The saved glycogen is used in the later part of the workout where under normal circumstances it would already have been used up and lead to exhaustion (2).
Caffeine is known to be a stimulant of the central nervous system, which is where the second theory plays; it states that by reducing the speed of substances that prevent neuronal firing, caffeine increases consciousness and speeds reactions.
The final theory suggests that caffeine may make muscle contractions stronger. Calcium, Sodium and potassium are transferred into the cells increasing permeability which results in more powerful contractions.
How Much Caffeine is Needed to Improve Athletic Performance?
This is where it becomes a bit tricky because different people react differently to caffeine, however a good measure is between two to three milligrams for every kilogram of body weight taken before the training session.
This translates into 175 mg for a person weighing 150 pounds. One eight ounce cup of percolated coffee contains approximately 100 mg, while a 12 oz. can of coke delivers 45 mg and a can of Red Bull 80 mg.
Or, if you’re a hard-gainer at the gym, you will probably take caffeine supplements, because they contain anywhere from 50mg to 200mg of caffeine per tablet. Personally, I vary between drinking a double espresso before my workouts or taking a high dose caffeine supplement, but not every day. I have found that the body soon gets used to dose, so you have to increase it. I don’t take more than 400mg of caffeine in any one day now.