According to a position paper by the International Society of Sports Nutrition, there is a plethora of evidence that shows that the acute consumption of caffeine can help both strength-power and endurance activities.1 And for you science geeks
1. Can Improve Energy Levels and Make You Smarter
Caffeine can help people feel less tired and increase energy levels (1, 2).
Caffeine is actually the most commonly consumed psychoactive substance in the world (3).
(After You Drink Coffee) the caffeine is absorbed into the bloodstream. From there, it travels into the brain (4).
In the brain, caffeine blocks an inhibitory neurotransmitter called Adenosine.
When that happens, the amount of other neurotransmitters like nor epinephrine and dopamine actually increases, leading to enhanced firing of neurons (5, 6).
Many controlled trials in humans show that coffee improves various aspects of brain function. This includes memory, mood, vigilance, energy levels, reaction times and general cognitive function (7, 8, 9).
2. The Caffeine Can Drastically Improve Physical Performance
Caffeine stimulates the nervous system, causing it to send signals to the fat cells to break down body fat (13, 14).
But caffeine also increases Epinephrine (Adrenaline) levels in the blood (15, 16).
This is the “fight or flight” hormone, designed to make our bodies ready for intense physical exertion.
Caffeine makes the fat cells break down body fat, releasing them into the blood as free fatty acids and making them available as fuel (17, 18).
Given these effects, it is not surprising to see that caffeine can improve physical performance by 11-12%, on average (29, 20).
Because of this, it makes sense to have a strong cup of coffee about a half an hour before you head to the gym.
3. Boost Speed
A fairly recent study determined the effects of caffeine on repeated sprint ability, reactive agility time, sleep and next day exercise performance. Did you get all that? Ten male athletes consumed a placebo or caffeine (6 mg per kg bodyweight) one hour prior to exercise. Significant improvements were shown after caffeine ingestion compared to placebo for the combined total time of each set and best sprint time. However, the coolest part of this study was that the caffeinated group still had better performance the following day. That’s right, the following day. Caffeine, however, had little effect on reactive agility time or sleep.5 Also, a caffeine-containing energy drink (3 mg/kg wt dose) increased repeated sprint ability during a simulated soccer game.
4. Increase Testosterone Levels
For real? Caffeine affects hormone levels? Check this out. Forty-two healthy adults were recruited from the Boston community who were regular coffee consumers, nonsmokers and overweight. That’s an interesting trio of things. Participants were randomized to five 6-ounce cups of caffeinated or decaffeinated instant coffee or water (control group) per day consumed with each meal, mid-morning and mid-afternoon. After four weeks, the consumption of caffeinated coffee increased total testosterone and decreased total and free estradiol in male subjects.12 What does this mean? It means I’m drinking lots of coffee.
5. May Lower Your Risk of Type II Diabetes
Type 2 diabetes is a gigantic health problem, currently afflicting about 300 million people worldwide.
It is characterized by elevated blood sugars in the context of insulin resistance or an inability to secrete insulin.
For some reason, coffee drinkers have a significantly reduced risk of developing type 2 diabetes.
The studies show that people who drink the most coffee have a 23-50% lower risk of getting this disease, one study showing a reduction as high as 67% (22, 23, 24, 25, 26).
According to a massive review that looked at data from 18 studies with a total of 457,922 individuals, each daily cup of coffee was associated with a 7% reduced risk of developing type 2 (diabetes).