Does creatine increase VO2max?

Creatine supplementation does not directly increase VO2max (maximal oxygen uptake). VO2max is determined primarily by cardiac output and peripheral oxygen extraction — factors not directly affected by creatine. However, creatine may indirectly improve aerobic fitness by enabling higher-quality interval training that drives VO2max adaptations.

Does the weight gain from creatine hurt endurance performance?

In weight-bearing activities (running, cycling uphill), the 1-2 kg water weight gain from creatine could theoretically reduce relative VO2max (ml/kg/min) and increase energy cost. For flat cycling or swimming, the extra weight is less impactful. Athletes should weigh the trade-off between creatine's performance benefits and the added body mass.

Should endurance athletes take creatine?

It depends on the sport demands. Endurance athletes who perform interval training, hill repeats, or sprint finishes may benefit from creatine. Pure steady-state endurance athletes (marathon runners, long-distance cyclists) see minimal direct performance benefit, though creatine may support recovery and training quality.

Creatine and VO2max: What Science Says

VO2max: The Gold Standard of Aerobic Fitness

Maximal oxygen uptake (VO2max) represents the maximum rate at which the body can consume oxygen during exercise. It is determined by three primary factors: cardiac output (heart rate x stroke volume), oxygen-carrying capacity of the blood (hemoglobin concentration), and peripheral oxygen extraction by working muscles (RB et al., 2017) .

Creatine supplementation does not directly target any of these three determinants, which explains why creatine does not increase absolute VO2max in controlled studies.

direct improvement in VO2max from creatine supplementation — creatine targets anaerobic, not aerobic, energy systems

Kreider et al., 2017

Why Creatine Does Not Directly Improve VO2max

The phosphocreatine system and the aerobic system operate on fundamentally different timescales:

Phosphagen system (creatine-dependent):

Powers 0-10 seconds of maximal effort
Does not require oxygen
Provides highest power output but shortest duration
Creatine supplementation enhances this system

Aerobic system (oxygen-dependent):

Dominates after 2 minutes of continuous exercise
Requires oxygen delivery and utilization
Provides lowest power output but unlimited duration
VO2max represents the ceiling of this system

Because VO2max is measured during progressive exercise lasting several minutes (typically a graded exercise test to exhaustion), the phosphagen system’s contribution is minimal. The test measures the aerobic system’s capacity, not the phosphagen system’s capacity.

Therefore, increasing PCr stores through creatine supplementation does not directly increase the maximal rate of oxygen consumption.

Relative VO2max and Body Mass Considerations

VO2max is often expressed in two ways:

Absolute VO2max (L/min) — total oxygen consumption, independent of body size
Relative VO2max (mL/kg/min) — oxygen consumption per kilogram of body mass

Creatine supplementation typically adds 1-2 kg of body mass (primarily intracellular water). This has implications for relative VO2max:

If absolute VO2max remains unchanged but body mass increases by 1-2 kg, relative VO2max will decrease slightly. For example:

A 70 kg runner with absolute VO2max of 4.2 L/min has relative VO2max of 60 mL/kg/min
After gaining 2 kg from creatine (72 kg, same absolute VO2max): relative VO2max drops to 58.3 mL/kg/min
This represents a ~3% reduction in relative VO2max

For weight-bearing activities like running, this modest reduction in relative VO2max could be counterproductive. For non-weight-bearing activities like cycling on flat terrain or swimming, the effect of extra body mass is negligible (TW et al., 2007) .

Indirect Aerobic Benefits of Creatine

While creatine does not directly improve VO2max, it may indirectly support aerobic fitness development:

1. Higher-quality interval training:

High-intensity interval training (HIIT) is one of the most effective methods for improving VO2max
Creatine enhances performance during high-intensity intervals (faster sprints, more power)
Better interval quality over weeks of training may produce greater aerobic adaptations
Some studies show that creatine-supplemented interval training leads to greater improvements in time trial performance

2. Increased training volume:

Creatine allows more total work during each training session
Greater training volume — provided recovery is adequate — drives aerobic adaptations
This is particularly relevant for concurrent training (strength + endurance)

3. Enhanced recovery:

Creatine may reduce exercise-induced muscle damage and inflammation
Better recovery allows more consistent high-quality training
Training consistency over months is one of the strongest predictors of aerobic fitness improvement

4. Mitochondrial support:

Mitochondrial creatine kinase supports efficient oxidative phosphorylation
The PCr shuttle facilitates energy transport within cells
Theoretical basis for creatine supporting mitochondrial efficiency, though direct VO2max effects are not observed

Sport-Specific Considerations

Running (distance):

Extra body mass is disadvantageous for weight-bearing endurance
Minimal direct performance benefit for steady-state running
May benefit runners who include sprint intervals or hill repeats
Most distance runners do not use creatine

Cycling:

Non-weight-bearing (on flat terrain), so extra mass is less impactful
Benefits for sprint finishes, hill attacks, and time trial surges
Some evidence of improved repeated sprint performance in cycling
Moderate rationale for road cyclists and strong rationale for track cyclists

Swimming:

Non-weight-bearing, extra mass is neutral
Benefits for explosive starts, turns, and sprint events
Limited benefit for long-distance swimming events
Widely used by competitive swimmers in sprint events

Team sports:

Combine aerobic endurance with repeated sprints
Creatine’s benefits for repeated sprint performance outweigh the modest VO2max reduction
Widely used and recommended for team sport athletes

The Training Quality Argument

The strongest case for endurance athletes using creatine is the training quality argument:

Even if creatine does not directly improve VO2max, it can improve the quality of training sessions that do improve VO2max. Better interval performance, enhanced recovery, and greater training consistency over months of preparation may ultimately lead to superior aerobic fitness — not because creatine directly increased VO2max, but because it enabled the training that did.

Summary

Creatine supplementation does not directly increase VO2max because it targets the phosphagen system, not the aerobic system that determines maximal oxygen uptake. The 1-2 kg weight gain may slightly reduce relative VO2max in weight-bearing activities. However, creatine may indirectly support aerobic fitness development by enhancing interval training quality, improving recovery, and enabling greater training volume. The decision to use creatine as an endurance athlete depends on the specific sport demands and the relative importance of sprint versus steady-state performance.