Sprinter Muscles - Why Are Sprinters So Muscular?
Sprinters are known for their impressive muscular physiques. Being strong and toned is one of the many benefits of sprinting.
This article will explore the scientific reasons behind the muscular build of sprinters and cover some commonly asked questions on this subject.
What This Article Will Cover:
- Reasons Sprinters Are Muscular
- Sprinting Fast Requires Strong Muscles
- Sprinting Increases Fast-Twitch Muscle Fibers
- Sprinting Burns Fat
- Sprinting Builds Muscle
- Sprinting Increases Testosterone & Growth Hormone Levels
- Sprinting Increases Your Metabolism
- Frequently Asked Questions About Sprinting
Sprinting Fast Requires Strong Muscles
Sprinting is an explosive and intense activity that requires a high degree of strength and power. Sprinting performance is determined by an athlete’s ability to apply large amounts of force to the ground in the proper direction.
While proper sprinting form is essential, sprinters must have adequate strength in their muscles to launch themselves down the track at high speeds.
A study by Peter Weyand found that:
“..the mechanism by which faster muscle fibers confer faster top running speeds in terrestrial cursors is not by decreasing minimum swing times but by increasing the maximum rates at which force can be applied to the ground.”.
Sprinters need to be strong enough to apply large amounts of force to the ground, as much as five times their body weight. Being able to apply large forces requires that most sprinters be remarkably muscular.
Sprinting Increases Fast-Twitch Muscle Fibers
Sprinting is an effective way to increase the number and size of fast-twitch muscle fibers in the body.
The human body has two muscle fibers: slow-twitch and fast-twitch. Slow-twitch muscle fibers are used for endurance activities, while fast-twitch fibers are responsible for quick and powerful movements.
Sprinting requires fast-twitch muscle fibers, which are bigger and stronger than slow-twitch fibers.
As sprinters train to improve their speed and power, their muscles adapt by increasing the number of fast-twitch fibers. These adaptations to sprinting result in a more muscular physique and improved sprinting performance.
Sprinting Burns Fat
Sprinting makes athletes more muscular by burning body fat, giving sprinters a lean physique.
According to research, sprinting burns fat faster than steady-state exercise, making it a time-efficient way to improve body composition.
When sprinting, the body requires energy to fuel the intense muscle contractions needed for speed and power. This energy comes from the breakdown of stored fat and glycogen in the body, resulting in a leaner and more muscular physique.
Since sprinters perform sprint training sessions every week as a part of their training program, they tend to exhibit lean physiques, making them look muscular.
Sprinting Builds Muscle
Sprinting is a form of resistance training that can build and strengthen muscles.
When sprinting, muscles are subjected to high tension and metabolic stress. The stresses of sprinting tell the body that it needs to repair these tissues, leading to increased muscle size, density, and tone.
Just like we can use strength training to activate hypertrophy in muscles, sprinting has a similar effect.
Sprinting Increases Testosterone & Growth Hormone Levels
Sprinting increases testosterone and growth hormone levels in the body.
Research on athletes who performed sprint training and strength training showed that these training forms increased testosterone levels. These increased testosterone levels help contribute to the muscular physiques displayed by sprinters.
Similarly, sprint training has been shown to increase levels of Human Growth Hormone, further clarifying why sprinters are so muscular and lean.
Testosterone and human growth hormone are essential for muscle growth, repair, and recovery from training.
Sprinting stimulates the production of these hormones, promoting muscle growth, low body fat levels, and a muscular physique.
Sprinting Increases Your Metabolism
Sprinting requires your body to utilize energy and metabolize waste products at high rates. Sprinting has been shown to elevate one’s heart rate both during and after sprint training, which suggests that your metabolism gets boosted as a result of sprint training.
After a sprinting session, the body continues to burn calories and fat at a higher rate, even at rest. This increased metabolic rate can help sprinters maintain a lean and muscular physique, especially if they eat enough protein and train regularly.
Frequently Asked Questions About Sprinter Muscles
Here are some common questions people ask about the muscles of sprinters.
What are the most important muscles for sprinting?
The most important muscles used in sprinting are the quadriceps, hamstrings, glutes, hip flexors, and calves, such as the gastrocnemius and soleus. These muscles are responsible for generating the power and speed needed for sprinting. As such, these are the leg muscles that make you faster.
Exercises for speed should target these muscle groups eccentrically and concentrically so that athletes can be adequately prepared for the demands of sprinting.
Additionally, sprinters need to have strong core and upper body muscles. Still, they should be light in the upper body. A strong core will help you counter the torso rotations during sprinting. In contrast, strong shoulders will help you swing your arms rapidly and counterbalance the actions of the legs.
While the leg muscles are most important for sprinting, the whole body should be trained.
What muscles are used in acceleration?
To accelerate quickly, athletes must apply large concentric forces to the ground. This requires that the quadriceps, glutes, calves, and calves be well-trained.
Research by JB Morin suggests that the hamstrings play a pivotal role in acceleration sprinting performance, stating that:
“...subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.”
Athletes who could effectively activate their hamstrings before ground contact while handling large eccentric forces were the fastest in acceleration. Simply put, the hamstrings are vital for rapid acceleration.
Another study by Marcus Pandy looked at the contributions of different muscles to acceleration performance. The results of that summary are summarized as follows:
- Soleus Muscle: Supports the athlete’s weight during ground contact, generating a sizeable upward impulse each step.
- Gastrocnemius: Contributes significantly to horizontal propulsive and upward impulses.
- Quadriceps: Provides significant support of the athlete’s body weight through upward impulses and handling braking forces.
- Glutes: The gluteus medius provides horizontal propulsion for each step. The gluteus maximus was found to primarily decelerate the swing leg so that the leg can stop moving forward and reverse downward toward the ground.
- Hamstrings: The hamstrings were found to act primarily as propulsive muscles which send the athlete forward down the track.
What are the most important upper body muscles for sprinting?
While the lower body muscles are the most important for sprinting, the upper body also plays a role in maintaining proper form and balance. For example, the arms counter any rotations in the upper body that result from the actions of the legs.
To sprint fast, one must have well-coordinated arm swings, optimal torso rotation, and the ability to hold their posture as their legs cycle aggressively.
The most important upper body muscles for sprinting are the core muscles, including the abdominals and back muscles, as well as the deltoids and pectoralis muscles. These muscles should be targeted through strength training.
Are glutes important for sprinting?
Yes, the glutes are vital for sprinting. The glute muscles are responsible for hip extension, an essential movement for generating power and speed during sprinting.
Sprinters and athletes who want to get faster should target the glutes through exercises such as sled sprints, back squats, hip thrusts, kick-backs (a.k.a. Reverse leg press), and similar exercises.
What percentage of muscles are used in running?
Nearly all the muscles in the body are used in running to some degree. Look at slow-motion videos or pictures of athletes when they sprint. You can see that every leg, core, and upper body muscle is activated at some point in the sprint.
This makes sprinting an excellent whole-body workout and is one reason why sprinters are so muscular.
In conclusion, sprinters are known for their impressive muscular physiques, and there are several scientific reasons for this.
The ideal sprinter body type strong muscles, particularly fast-twitch muscle fibers, which are larger and stronger than slow-twitch fibers.
Sprinting also burns fat, builds muscle, increases testosterone and growth hormone levels, and increases metabolism.
The most important muscles for sprinting are the quadriceps, hamstrings, glutes, and calves. At the same time, the core muscles are also essential for maintaining proper form and balance.
- Weyand, P. G., Sternlight, D. B., Bellizzi, M. J., & Wright, S. (2000). Faster top running speeds are achieved with greater ground forces not more rapid leg movements. Journal of applied physiology (Bethesda, Md. : 1985), 89(5), 1991–1999. https://doi.org/10.1152/jappl.2000.89.5.1991
- Sellami, M., Dhahbi, W., Hayes, L. D., Kuvacic, G., Milic, M., & Padulo, J. (2018). The effect of acute and chronic exercise on steroid hormone fluctuations in young and middle-aged men. Steroids, 132, 18–24. https://doi.org/10.1016/j.steroids.2018.01.011
- Nevill, M. E., Holmyard, D. J., Hall, G. M., Allsop, P., van Oosterhout, A., Burrin, J. M., & Nevill, A. M. (1996). Growth hormone responses to treadmill sprinting in sprint- and endurance-trained athletes. European journal of applied physiology and occupational physiology, 72(5-6), 460–467. https://doi.org/10.1007/BF00242276
- Morin, J. B., Gimenez, P., Edouard, P., Arnal, P., Jiménez-Reyes, P., Samozino, P., Brughelli, M., & Mendiguchia, J. (2015). Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production. Frontiers in physiology, 6, 404. https://doi.org/10.3389/fphys.2015.00404
- Pandy, M. G., Lai, A. K. M., Schache, A. G., & Lin, Y. C. (2021). How muscles maximize performance in accelerated sprinting. Scandinavian journal of medicine & science in sports, 31(10), 1882–1896. https://doi.org/10.1111/sms.14021