When it comes to getting in shape, many people are willing to try any tricks they need to reach their goals faster. For many years, protein shakes were seen as essential after a workout. But more recently, in addition to protein shakes, many are also turning to pre-workout supplements. These are marketed as being able to enhance your workout by increasing energy, boosting metabolism and improving muscle growth. They’re usually taken as a tablet or consumed as a drink around 30-45 minutes before a workout.
But despite the high demand for pre-workout supplements, the lack of research, variations in the products, and uncertainty about what they contain makes it difficult for consumers to understand how effective they really are – and whether they do what they claim.
Here we take a look at some of the most common pre-workout ingredients to see whether there’s any evidence they work.
Caffeine is typically added to most pre-workout supplements as a stimulant to reduce fatigue and increase alertness. There’s good evidence showing that consuming caffeine around 30-60 minutes before exercise can improve endurance performance (such as running or cycling) typically by as much as 20% during exercise lasting one to two hours. It may also make your workout feel slightly less difficult.
The main downside of caffeine is that high doses (between 5-13 milligrams of caffeine per kilogram of body weight – so around 375mg-975mg for a 75kg person) have reported side-effects, such as an upset stomach, confusion and poor sleep. For perspective, a single espresso shot only contains about 75mg of caffeine. But smaller doses (around 3mg per kg of body weight) have still been shown to be effective with fewer or no side-effects. Most pre-workout supplements contain between 85mg-300mg of caffeine.
It might seem easier to simply drink coffee before exercise, but depending on where your coffee comes from, the caffeine content can vary considerably. This may mean that you have either too much, or not enough, whereas a set dose from a supplement can be easily controlled.