Creatine and endurance performance: does it help or harm?

Creatine is one of the most well-researched supplements in sports nutrition. While its effects on strength and sprinting are clearly confirmed, the question remains: does it make sense for endurance athletes as well? Scientific studies have yielded mixed results – sometimes beneficial, sometimes more detrimental.

How can creatine help endurance athletes?

• Increased time to exhaustion – some studies have shown that after 6 days of supplementation (20 g/day), the ability to last longer under stress while running on a treadmill improved.

• Faster recovery – creatine combined with carbohydrates promotes muscle glycogen resynthesis , which is important during multiple training sessions or stage races.

• Reducing inflammation and oxidative stress – research suggests that creatine can speed up recovery after long exercise.

• Advantage in sprints – in sports where final attacks or finishes are crucial, increased energy reserves can provide a competitive advantage.

When can creatine be a disadvantage?

• Weight gain – supplementation usually leads to an increase of 1–2 kg due to water retention in the muscles.

• Trail running – a study showed that for trail runners, this weight gain meant worse performance, especially on climbs.

• The difference between sports - in disciplines where body weight is transferred (running), the weight effect is negative, while in cycling or swimming it may not play a significant role.

What do studies show with intervals and spurts?

• In triathletes, supplementation led to an 18% improvement in performance in 15-second sprints after riding or running at submaximal intensity.

• Cyclists improved their performance in the final sprints during interval time trials, although their overall race time did not change significantly.

This means that creatine may be of interest mainly for sports that combine endurance with repeated intense stretches.

Practical uses of creatine for endurance athletes

Creatine may have its place in endurance athletes, especially during the period of volume training , when it will support regeneration and allow them to handle a higher training load. On the other hand, it should be taken into account that supplementation leads to an increase in weight by 1–2 kg due to water retention in the muscles. Research has shown that in disciplines where body weight is transferred (e.g. running, especially in hilly terrain), this effect can actually worsen performance. Therefore, we can rather recommend using creatine during the training period and ending supplementation well in advance (approx. 6 weeks) before the race itself , in order to eliminate the risk of a negative effect of higher weight on performance itself.

Summary

• Helps: with regeneration, glycogen restoration, reduction of inflammation and in final spurts.

• It can have a negative effect: in sports where body weight plays a big role - especially running and cycling uphill or on trails.

• Neutral effect: for swimming or cycling, where weight gain is not so limiting.

Creatine is not a universal supplement for all endurance athletes, but if your sport relies on intervals, sprints, or rapid recovery , it can be very useful.