Cyclists and runners are often regarded as some of the fittest athletes on the planet, thanks to their incredible endurance and muscle strength.
However, despite the overlaps in endurance, cyclist legs vs runners legs are very different, with the two sports requiring distinctive training and injury prevention.
Cyclists are generally known for their vascular and muscular leg profile, while runners often have a leaner leg profile.
However, there is more to their appearance than meets the eye. In fact, there are many fine-tuned adjustments specific to the demands of both cycling and running.
Understanding the differences in anatomy, muscle structure, and the risks of injury can help you comprehend sport-specific training methods and what to expect as you train.
In this article, we’ll explore the differences between cyclist legs vs runners legs in detail, covering:
- Anatomy Of Cyclist Legs Vs Runners Legs
- Training Methods for Cycling Muscles Vs Running Muscles
- What To Expect As You Train
Let’s dive in!

Anatomy of Cyclist Legs vs Runners Legs
Cyclists Legs
The legs of a cyclist are the envy of many fitness enthusiasts.
The defined muscle tones come from the aerobic nature of cycling, which requires a lot of power output from the legs, consistently.
As cyclists pedal, they use in tandem their hamstrings, quadriceps, and glutes to employ a large amount of force.
This repetitive motion leads to muscle hypertrophy, with a focus on the quadriceps as the primary muscle group used.
Whilst cyclists have impressive leg muscles, one thing you can expect anatomically is an unbalanced muscle structure, with the quads being significantly larger than their hamstrings and glutes. This can lead to injury-prone imbalances.
When training as a cyclist, you need to consider the growth of your quad strength as a primary goal.
This is especially important for inclines, sprinting, and covering long distances.
Another important point to consider regarding cyclist legs vs runners legs is which sport you may be more effective at depending on the length of your legs.
Generally, someone with shorter, more muscularly compact legs would produce better results on a bike, in comparison to running.
This is only a general trend rather than a rule. Though the average height of a Tour de France cyclist is 181 cm (5 ft 9 in), there are much taller cyclists in the pro peloton – former Irish Champion Conor Dunne being a great example at 204 cm (6 ft 7 in).
So in terms of what to expect with cycling training, this is what you should know in summary about leg anatomy:
- You should expect a muscular, strength-orientated leg profile through cycling training.
- You will look to create a quadricep-focused leg muscle profile, as the sport requires accentuated strength in quads, with hamstrings, glutes, hip flexors, and calves as secondary components
- You will engage in a repetitive function of training that requires a repetitive engagement of the legs regardless of long-distance or short speedy inclines.
- Be wary of overdeveloping muscle imbalances to reduce the risk of injury.
Runners Legs
Runners, on the other hand, have different anatomical structures through different means of leg development. Their legs are less bulky, with a more balanced muscle distribution.
As opposed to cycling, running is a sport that requires you to carry your upper body weight, which engages the leg muscles with a more even distribution. This leads to a more holistic leg muscle anatomy.
Of course, when you run you still engage your quads, but not to the same extent as cyclists.
As you train for running, the emphasis you would give is across the quads, hamstrings, glutes, hip flexors, and calves.
Furthermore, runners also engage in a wider variety of training, such as speedrunning, incline running, and diverse strength training (though cyclists should do strength training too), which promotes diverse leg muscle development.
So in terms of what to expect with running training, this is what you should know about leg anatomy:
- You should expect a leaner leg profile through running training.
- You will look to create a balanced leg muscle profile, as the sport requires distributed strength in quads, hamstrings, glutes, hip flexors, and calves.
- You will engage in a wider variety of training that requires a diverse engagement of the legs such as sprinting and incline running.
Fast Twitch Fibers Vs Slow Twitch Fibers
To put it in basic terms, muscle fibers of the fast-twitch variety are designed for brief, forceful surges of energy.
This stands in contrast to slow-twitch fibers, which are meant for endurance activities such as long-distance running or cycling.
Generally, cyclists make greater use of fast-twitch muscle fibers than runners. This is due to employing muscle to generate more power at a faster frequency. This leads to defined leg structures.
On the other hand, runners tend to rely more on slow-twitch muscle fibers, which are suited, as mentioned, for long-distance training.
This results in muscles that appear smaller, but are fully functional for the purpose of running.
However, such a broad comparison would not be entirely accurate.
A more precise statement would be that slow-twitch muscle fibers are predominant in the legs of long-distance runners and cyclists, while fast-twitch muscle fibers are predominant in the legs of sprint cyclists and runners.
And of course, cyclists make plenty of use of slow-twitch muscle fibers too on long, endurance rides.
Training Methods for Cycling Muscles Vs Running Muscles
Naturally, the best thing to do to train for cycling and running – is you guessed it – running and cycling.
Training in the sport you want to excel in is essential for developing your legs into machines that are better equipped for that particular activity.
Beyond the direct practice of cycling or running though, there are some specific training methods you can expect for both cycling and running.
Furthermore, cross-training can have massive rewards too, even if the main focus of your training should be in your chosen sport.
#1: Training Methods For Cyclists’ Legs
What you can expect when it comes to training for cycling is a development of both fast and slow-twitch muscle fibers and a focus on quadricep muscle growth.
Cyclists should incorporate strength and mobility exercises, including squats, deadlifts, and variations of lunges, to prevent the anatomical imbalances mentioned earlier.
Ultimately, building leg muscle in the gym is typical training as a cyclist to help you pedal with power.
In addition, as a cyclist, you could benefit from strengthening your core and upper body during training to keep your posture stable and steady whilst riding, in support of your legs.
- Find out more about Strength Training for Cyclists here!
#2 Training Methods For Runners’ Legs
What you can expect when it comes to typical training for running is the development of slow-twitch muscle fibers and a balanced distribution of muscle.
This is a natural result of endurance running training, building muscle for those long-distance runs.
In addition, to accommodate muscle growth and get bigger legs as a runner, you can expect to incorporate high-intensity interval training to build up fast-twitch muscle fibers to aid sprinting.
Risk Of Injury For Cyclist Legs vs Runners Legs
In addition to a less developed physique, a running or cycling regimen that neglects leg strength training can also result in injuries.
Runners often experience tightness in their calves and suffer from shin splints, while cyclists may have tight hip flexors or hamstrings due to prolonged periods of sitting on the saddle.
To prevent injury as both a cyclist and runner, incorporating yoga and stretching will be really beneficial, as well as improving your flexibility.
What To Expect As You Train
Based on these anatomical differences, the variety of fast-twitch and slow-twitch muscle fibers, and training methods, you can expect these factors to come into play as you train.
Cycling Legs
- Cycling does not put too much pressure on the joints as it is low-impact. For athletes with chronic joint injuries in their legs, cycling can be a great option.
- Cycling aids the development of leg muscles engaged in working against resistance, such as quadriceps, hamstrings, and glutes.
- Cycling offers cardiovascular benefits and increased activity of your metabolism through the deployment of your legs, benefits which are shared with running.
Running Legs
- Running involves balanced and greater muscle use, meaning you could burn more calories.
- Due to this greater spread of muscle engagement, running could improve your cardiac function and the activity of your metabolism.
- Running engages the leg muscles more holistically than cycling.
- Running exerts greater impact forces on the joints.
- Due to this high-impact nature, you could be more likely to get an injury.
Cyclist Legs Vs Runners Legs: Conclusion
Ultimately, the primary difference between cyclists’ legs and runners’ legs is in the type of muscle fibers utilized, and the muscle distribution created during training.
Cyclists generally rely more on fast-twitch muscle fibers for high-power, high-cadence movements, while both runners and cyclists use slow-twitch muscle fibers for endurance activities.
Furthermore, a lack of strength training in the legs can lead to different types of injuries for each group, such as tight calves and shin splints for runners, and tight hip flexors or hamstrings for cyclists.
So remember, regardless of whether you run long distances, cycle, sprint up hills, or move at high speeds, it’s important to maintain varied training for your legs to avoid injury and maximize the effectiveness of your training.