Updated: May 15, 2019
Exciting new research has just been published on the effect caffeine can have on athletic performance over several days. This is of specific interest to athletes who compete in multi-day endurance events and consider taking caffeine before running or throughout the event.
Caffeine before running and other sports
Caffeine has been shown to have positive effects on performance in cycling, running, cross-country skiing and rowing for short as well as long-duration events. All of these studies have however used a one day protocol.
The question that Stadheim et al. wanted to answer was: Would the improved performance due to caffeine supplements on the first day have a negative effect on the following day’s performance, if one assumes that you would have increased muscle damage due to the greater effort on the first day?
What the researchers did
To test this, the researchers took 8 elite cross-country skiers and made them exercise on three different occasions which consisted of a 10 minute all-out test, on a polling ergometer, on 2 consecutive days. They randomly assigned the skiers to have one of 3 drinks 45 minutes before the test started on each day. The drinks consisted of either a 3 mg/kg caffeine solution, a 4.5 mg/kg caffeine solution or a placebo drink containing no caffeine.
Results: Effects of caffeine on performance during multi-day events
Their results were very interesting. The athletes all performed significantly better on both days compared to the placebo group when they consumed caffeine. This happened despite the caffeine group reporting more muscles soreness and the increased levels of creatine kinase in their blood showing that they had indeed sustained more muscle damage during the first day’s session than the placebo group.
The answer to their question is thus: Yes, caffeine supplements can lead to greater muscle damage due to an increased workload BUT it can still enhance performance despite the greater muscle damage.
Important to note
It is, however, important to note that this is the first study to investigate this specific research question and the results should be replicated by other researchers and under different conditions and during different activities before we can apply it to the wider population.
This study also only looked at short duration exercise and the effect on performance on long distance multi-day events has not been studied. These events may produce very different results, as endurance races can lead to much greater muscle damage.