The Physical Difference Between Long Distance Runners & Sprinters

Sprinting isn't just a more explosive form of running — it also involves various biomechanics, including differences in stride length. A long-distance runner's body is lean and relies on slow-twitch muscle fibers during training. Sprinters rely on fast-twitch muscles and typically have a heavier build.

Trying to decide between sprinting and long-distance running? Can you be great at both? Not really. Sure, you can do both activities for recreational purposes and overall fitness, but your genetics and training routine will ultimately determine what you're best at.

In general, sprinters are genetically gifted with a larger number of fast-twitch muscle fibers compared with long-distance runners. This allows them to perform explosive movements and engage in high-intensity exercise for short periods. The same goes for powerlifters, bodybuilders and other strength athletes, explains the National Academy of Sports Medicine (NASM).

Your body begins to use fast-twitch muscle fibers when the slow-twitch fibers can no longer meet the force demands of a particular activity. Fast-twitch fibers can generate more force in a shorter time than slow-twitch fibers, according to the American Council on Exercise. Additionally, they have the greatest impact on muscle size and definition. That's one of the reasons sprinters are typically more muscular and have a larger build than long-distance runners.

Compared with slow-twitch fibers, fast-twitch muscle fibers fatigue more quickly and hence are more suited for short-duration anaerobic activities like sprinting and weight lifting. As the American Council on Exercise notes, lifting heavy weights or performing explosive, power-based movements is the best way to activate fast-twitch fibers.

Sprinters and strength athletes have 60 to 80 percent fast-twitch fibers, reports a June 2012 review featured in the Journal of Strength and Conditioning Research. Endurance athletes, including long-distance runners, have 90 to 95 percent slow-twitch muscle fibers.

However, most studies are conflicting, and it's still unclear whether or not exercise can cause a shift in fiber type and how much of a role genetics play in fiber type composition.

Slow-twitch fibers are smaller and less forceful but more resilient to fatigue than fast-twitch fibers. Since they rely on oxygen to function properly, they are better suited for long-duration aerobic activities, notes the American Council on Exercise.

These types of muscle fibers come into play when your muscles contract during exercise. High-rep training, isometric movements, circuits and other activities that get your heart pumping faster will activate the slow-twitch fibers and improve their efficiency.

As mentioned above, slow-twitch fibers rely on oxygen for energy. This allows them to sustain continuous muscle contractions over a long time. That's why endurance athletes can run longer and perform more reps than strength or power athletes. However, current evidence suggests that it may be possible to change your muscle fiber type through exercise.

Read more: 10 Exercises to Increase Your Running Speed

The Journal of Strength and Conditioning Research review indicates that cycling, long-distance running and other aerobic activities may increase the number of slow-twitch fibers. Strength training, on the other hand, may lead to a larger number of fast-twitch fibers. Furthermore, a lack of exercise may reduce the number of fast-twitch fibers and increase the percentage of slow-twitch fibers.

One of the primary differences between sprinters and runners lies in muscle fiber type, as discussed earlier. This factor plays a key role in athletic performance. Additionally, a long-distance runner's body is less muscular, especially in the upper region, compared with a sprinter.

Another difference between the two is that sprinters often have more developed glutes than runners, according to the experts at Setanta College. The gluteus maxiumus, which is the largest muscle in your body, stabilizes the lower back and sacroiliac joints while exerting force and power. Therefore, having strong glutes is essential for athletic performance.

Sprinters also tend to have greater curvature in the lower back compared to long-distance runners. This characteristic may be due to the increased muscle bulk in the gluteal region, explains Setanta College.

A January 2015 article published in Exercise and Sport Sciences Reviews discusses the age-related changes and other health characteristics in long-distance runners versus sprinters. As the scientists note, runners have higher levels of aerobic capacity than sprinters. The latter, though, still have higher maximal aerobic capacity than sedentary people.

Read more: 24 Health Benefits of Running That Will Finally Convince You to Give It a Try

As far as body composition is concerned, both types of athletes seem to be in better shape as they age compared with untrained individuals. However, aging sprinters tend to preserve more lean mass than long-distance runners, which can be helpful in their senior years. Although bone density is typically higher in both sprinters and middle-distance runners than in long-distance runners, all groups experience a decrease in bone strength over the years.

Both runners and sprinters are prone to sports-specific injuries, according to the above review. Elite sprinters, for example, have greater odds of developing injuries to their tendons and ligaments. Long-distance runners and endurance athletes, in general, tend to develop cardiovascular problems, but they're still healthier in the long run compared with the average person. Both sports may decrease the risk of heart disease.

Your ability to sprint or run long distances depends partly on your genetics and partly on your training routine. The good news is you don't have to choose between the two. Balancing speed and endurance is often the key to enhanced athletic performance.

If, say, you're a great sprinter and want to get better at running, you can train your slow-twitch muscle fibers. The American Council on Exercise recommends isometric exercises for this purpose. Planks, low squats and triceps extensions against a wall are just a few examples. High-rep strength training, bodyweight training and circuits with lighter weights promote slow-twitch fiber development too, so you may add them to your routine.

Read more: The 8 Best Stretches to Do Before Running

Runners, on the other hand, can build strength and explosiveness by training their fast-twitch fibers. Heavy lifting and explosive movements with kettlebells, dumbbells or exercise balls are all a good choice. Bodyweight exercises like pull-ups, push-ups and chin-ups can be just as effective. Rest for 60 to 90 minutes between exercises so your muscles can recover and get the energy needed to start all over.

You may also alternate between sprinting and running to get the best of both worlds. Go out for a run every weekend or whenever you have some spare time. Sprinting is less time-consuming, so you can squeeze a quick workout into your schedule on most days. Either way, start with small steps and increase your speed or distance as you progress.