Cyclist Legs vs Runners Legs: Comparing Muscles Worked

Whether you are a runner who has a friendly competition with a cyclist about whose sport reigns supreme, or perhaps the roles are reversed, there’s always a lot of interest and intrigue about biking vs running in terms of which is a better workout.

When it comes to cycling vs running for exercise, there are quite a lot of factors to compare, and it’s not easy to determine a running vs cycling winner, which is largely why the debate lives on. 

However, while we can’t necessarily determine whether biking is better than running or if running is better than biking overall, we can compare certain aspects of the two sports.

For example, one common question people have is, “What are the differences between cyclist legs vs runners legs?” In other words, what do biker legs vs runner legs look like?

In this article, we will compare a cyclist legs vs runners legs, looking at how each sport changes the physique of your legs and the muscles worked running vs cycling.

We will cover the following: 

  • How Do Cyclist Legs vs Runners Legs Compare?
  • What Do Runners’ Legs Look Like?
  • What Do Cyclists’ Legs Look Like?
  • Muscles Worked By Running vs Cycling

Let’s dive in! 

A cyclist with strong calves.

How Do Cyclist Legs vs Runners Legs Compare?

Whether you are a cyclist, runner, triathlete, or everyday gym goer who does a mix of indoor cycling workouts and indoor treadmill runs or outdoor runs, you may wonder, “What are the differences between cyclists’ legs vs runners’ legs?”

After all, we all hope that our workout routines will eventually result in the physique and muscular build that we are going for.

Although most people would characterize marathoner legs, sprinter legs, biker legs, and cyclist’s legs as generally muscular, there are differences in the muscular build of the legs of cyclists vs runners.

These differences in muscle size and definition in runner vs cyclist legs are mostly attributable to the differences in the muscles worked running vs cycling as well as the volume, intensity, and style of training.

It is important to note that while we will attempt to compare runner legs vs biker legs, the characteristics that we point out about the legs of cyclists vs runners will be sweeping generalizations and will mostly apply to the elite athletes in cycling and running.

A person mountain biking.

Running and cycling have both become quite inclusive sports, drawing participants from all different backgrounds and body sizes. 

You can be a tall, thin, sinewy marathon runner or one who has been medically classified as obese based on your BMI or even body fat percentage.

Despite these stark differences in body types, both athletes can absolutely consider themselves runners if they run or jog with some amount of regularity.

The same can be said for cyclists. You can find elite Tour de France winners with very little body fat that will have a certain cyclist leg aesthetic.

However, there are also plenty of everyday recreational cyclists who might be much shorter, heavier and have quite a high body fat percentage such that you can’t really see any noticeable muscle definition in their legs.

Again, both cases will absolutely qualify as biker legs since both people exercise by cycling, but the muscular build, definition, and characteristics of these cyclists’ legs will be quite different.

A mountain biker.

Thus, it would be virtually impossible to have a meaningful discussion comparing cycling legs vs running legs if we include the entire population of runners and cyclists since the demographics and body types now span the gamut.

For that reason, we will compare the general characteristics of the legs and muscular build of elite runners vs bikers.

The broadest, most general overview that demonstrates the differences in the cyclist’s vs runner’s legs matchup is that:

Cyclists tend to have very ripped or muscular legs that are vascular and popping with defined muscles but in specific muscles or an imbalanced distribution, whereas a marathoner’s legs are leaner overall with a more balanced distribution of muscle mass.

However, in order to make a clearer head-to-head comparison of a biker’s legs vs runner’s legs, let’s look at the typical appearance of cyclists’ legs and runners’ legs separately.

Runners on a track.

What Do Runners’ Legs Look Like?

There are some prominent differences between long-distance runners’ legs and sprinters’ legs.

Most elite marathoners have a lean build, low body fat percentage, and toned legs with a sinewy appearance.

The muscles are all relatively sculpted yet long and lean but in a generally balanced distribution such that there aren’t necessarily bulging calves or little quads.

This is because running strengthens and tones all of the major muscles in the legs.

The high-mileage and catabolic nature of distance running training leads to lower body fat, smaller muscles, and a higher percentage of slow-twitch muscle fibers. 

These are the aerobic muscle fibers that are smaller in nature with much more fatigue resistance but are less strong and powerful for rapid force production than fast-twitch muscle fibers.

A strong sprinter.

A sprinter’s legs or a middle-distance runner‘s legs actually look quite a bit different from a marathon runner’s legs at the elite level.

Sprinters tend to have very muscular, sculpted, and thicker legs, and although they are lean in terms of their body fat percentage, their total muscle mass and build are usually bigger than a distance runner.

The legs of a sprinter will have a higher proportion of fast-twitch muscle fibers, which are the larger muscle fibers that are capable of producing lots of force rapidly, but that fatigue quickly.

What Do Bikers’ Legs Look Like?

A cyclist’s legs generally resemble a splinter’s legs more than a distance runner’s legs due to the anabolic or muscle-building nature of cycling vs running long distances.

One of the primary differences between cyclists’ legs vs runners’ legs, besides having larger muscles, is that the muscle distribution pattern in the legs of a cyclist is less balanced than with the legs of a runner.

A peloton of cyclists.

Cycling tends to be more of a quad-dominant activity, giving cyclists a classic “teardrop“ definition of the quads, especially for riders who tackle lots of climbs.

Indoor cycling workouts may not necessarily yield the same muscle definition for a cyclist’s legs, largely due to the absence of significant climbing in the saddle.

However, if you do a lot of HIIT workouts or sprints on the bike, you can still achieve this classic teardrop quad aesthetic because high-intensity cycling under resistance targets the fast-twitch (type II muscle fibers).

These muscle fibers are more responsive to hypertrophy than slow-twitch muscle fibers, giving you greater gains in muscle mass and definition with high-intensity cycling workouts vs long endurance rides.

The cycling pedal stroke does still work the hamstrings, glutes, and calves to some degree, but the emphasis is often on the quads, particularly for shorter, faster rides where power is maximized.

A peloton of cyclings riding fast.

The legs of elite cyclists often tend to be more vascular (more visible blood vessels) than the legs of elite runners.

Also, when comparing elite cyclists vs runners, cyclists often have shorter legs, while marathon runners have longer legs.

This is because stride length may be optimized when running with a slightly longer leg, although this is not true across the board.

With cycling, you may be able to generate more powerful pedal strokes with slightly shorter legs.

Finally, one superficial difference between runners’ legs and cyclists’ legs is that competitive cyclists often shave their legs in order to improve aerodynamics.

This is less common among elite and professional marathon runners.

A group of sprinters on a track.

Muscles Worked By Running vs Cycling

There’s a lot of overlap between the muscles worked by running and the muscles worked by cycling because both activities are mainly lower-body exercises.

Cycling and running both primarily target the glutes, quads, hamstrings, and calves, as well as the hip flexors and adductor (inner thigh) muscles.

However, there are different stresses placed on the muscles worked by cycling vs running based on the different movement patterns and the fact that running is a high-impact, weight-bearing exercise, whereas cycling is a low-impact, weight-supported exercise.

With cycling, your body weight is supported on the seat, so there’s little core and upper-body muscle activation. However, the resistance with cycling can be quite high if you are going up hills in a hard gear, which can help build your quads.

When cycling uphill, more of the workload is shifted to the quads and glutes as long as you stay seated in the saddle, and with running, more of the workload is shifted to the posterior chain muscles such as the glutes, calves, and hamstrings when you run uphill.

To learn more about how different exercises shape your physique, check out our guide to whether squats make your butt bigger.

A back squat.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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