By: Dr. Sean Delanghe BSc (Hons), DC

We’re close to race day for many- and it’s too late to get more fit, but are there still some ways we can get faster on race day?

YES- by drafting! But how much does it actually help?

A 2025 systematic review published in the Journal of Biomechanics examined the research on aerodynamic drafting across sports such as running, cycling and swimming. Here is what the research actually shows.

What Did the Researchers Do?

Beaumont and colleagues conducted a systematic review of research investigating drafting and its effects on performance across mass-start sports.

The researchers examined studies using different methods, including wind-tunnel experiments, computational fluid dynamics (CFD), physiological measurements and observations of athletes during competition.

The review included evidence from sports such as cycling, running, swimming, kayaking and race walking. Interestingly- approximately 60% of the studies included in their review had been published during the preceding decade- interest in this topic is on the rise!

What Did They Find?

1. Drafting Can Substantially Reduce Air Resistance

The findings strongly support the idea that drafting reduces aerodynamic resistance and can lower the energy required to maintain a given speed- no sprurpise here!

The magnitude of the benefit varies considerably by sport. In cycling, for example, drafting within a group can reduce aerodynamic drag by up to approximately 95% under favourable conditions.

Running is a little more complicated because of the slower speeds- so how much can it reduce drag and therefore improve performance?

2. Drafting Improves Marathon Performance

Several studies included in the review examined drafting during distance running.

One computational study found that running in an optimal formation could:

• Reduce aerodynamic drag by more than 60%
• Improve running economy by approximately 4.4% in the moment
• Or, on average 3 minutes and 28 seconds over a marathon – or just under 3%

Another modelling study estimated that carefully arranged drafting formations could produce marathon time savings of approximately 2.6 minutes.

These numbers are interesting, but there is an important distinction: reducing aerodynamic drag by 60% does not mean reducing your total energy expenditure by 60%. And a 4.4% icnrease in running economy does not mean a 4.4% increase in running speed.

On top of that, this all assumes a close to 2-hour marathon. How does this translate to slower running speeds? That we don’t fully know!

3. The Position of the Runners Matters

Unforunately seeing this benefit is not from simply a matter of being somewhere behind another runner.

The shape and size of the group, the distance between runners and their relative positions all influence how air moves around them.

For example, one study found that running second in a line of five runners produced particularly favourable aerodynamic conditions- being in the middle was better than being at the back of the pack!

That being said, the most aerodynamically efficient arrangement in a computer simulation may not be the most practical formation during a real race, where runners change positions, wind direction varies and maintaining a group requires coordination.

4. Drafting May Have Benefits Beyond Aerodynamics

Drafting may also help athletes maintain a consistent pace and reduce the need to make repeated decisions about how fast to run.

Running with a group can make it easier to settle into a rhythm, particularly during long races. There may also be psychological benefits associated with sharing the workload and having other runners to follow.

If you have a good pacer who you can trust- the study defintiely noted that there’s osmething to be gained here!

What Are the Limitations of the Research?

This is where we need to be careful about interpreting the results.

Although the review brings together a substantial body of research across several sports, the number and quality of studies vary between disciplines. Evidence from cycling cannot automatically be applied to running, and results from swimming are even less directly transferable because water behaves differently from air.

Many of the most impressive predictions about marathon time savings come from computer simulations. These models can help us understand the underlying physics, but they rely on assumptions about running speed, body position, wind conditions and the relationship between aerodynamic resistance and metabolic energy expenditure.

Laboratory studies provide useful physiological measurements, but they cannot perfectly reproduce the conditions of a competitive marathon.

We therefore have good evidence that drafting reduces aerodynamic resistance. We have less certainty about exactly how many seconds or minutes an individual runner will save in a real race.

What Does This Mean for Runners?

The practical takeaway is relatively simple.

If you are running a marathon or another long-distance race, running behind a similarly paced athlete or group can be a sensible strategy, particularly when conditions are windy.

Rather than constantly moving around to find the theoretically perfect position, focus on maintaining an appropriate pace, running efficiently and avoiding unnecessary surges. A slightly imperfect draft is still potentially useful if it allows you to run comfortably at your target effort.

For elite runners, where small differences in performance can determine the outcome of a race, aerodynamic positioning may be particularly valuable. For recreational runners, the benefit will depend on running speed, weather conditions and how much of the race they spend sheltered.

The Bottom Line

This systematic review supports the conclusion that drafting is an effective way to reduce aerodynamic resistance in endurance sports.

In running, the effect appears meaningful enough to influence performance, particularly at high speeds and under favourable conditions. However, the largest predicted marathon time savings come from modelling studies, and we should not assume that every runner will experience the same benefit.

Drafting is a useful race strategy, not a substitute for fitness, training or appropriate pacing.