Long distance running may not be ideal if you are trying to build up muscle and get a ripped physique, and the debate over sprints versus distance running has become heated at times. A look at the differences in build and physical conditioning between athletes who run for longer distances and those who sprint instead will show exactly why this form of workout may be a better choice for lifters and bodybuilders.

Sprinting causes anabolic changes in the body while running for long distances results in catabolic changes instead. If you are trying to build muscle than this is a big concern. Each type of running will also activate different muscle fibers, some that are intended for increased muscle and some that are not. Distance running may also increase the risk of injury and repetitive strain damage because of the increase in distance traveled and time spent on the workout.

Catabolic vs. Anabolic

Catabolic exercise causes the body to break down muscle tissue and use these reserves for energy during the workout.

Anabolic workouts do the opposite and they encourage muscle growth and retention. Low intensity distance running will not help you lose as much body fat as sprinting will.

Less fat means your muscles will be more visible and this can give you that ripped look. More muscle and less fat means that the muscles can be seen sooner and over time you can get the perfect physique and awesome size that you are trying for.

Slow Twitch vs. Fast Twitch Muscle Fibers

There are two main types of muscle fibers, fast twitch and slow twitch. Each type has specific advantages in certain areas, and one may help a distance runner while the other benefits sprinters and encourage muscle creation rather than muscle loss.

Fast twitch fibers are utilized during periods when peak performance is needed for shorter periods. Activities like sprinting that use the fast twitch fibers will be anabolic and help you create well developed muscle in your upper body and lower body both.

Slow twitch fibers used during distance running are catabolic in nature and can cause muscle loss. Only one type of muscle fiber will be activated at a time, so if the slow twitch groups are active the fast twitch fibers can not engage.

For serious lifters and bodybuilders the goal is to develop massive muscles and this can be accomplished better with the short activity bursts that sprints have. Going for long distances may cannibalize your muscles and cause a loss of size and power instead. Fast twitch muscle fibers start off thicker than the slow twitch fibers and will grow much faster if you use the right training methods and follow the proper nutritional guidelines. Without the proper nutrients all of your efforts could be wasted and your results may be less than satisfactory.

Injuries & Repetitive Strain

Since sprints are short in duration these place less repetitive strain on the body and can minimize the risk of injuries. Distance running is performed over long time periods and injuries are very common due to overuse. A sprint requires more work from the body because your muscles will contract to the maximum amount and this is not the case with long distance running.

Why Is Sprinting Better For Muscle Growth?

During and immediately after sprints the body produces greater amounts of important hormones including testosterone. This increase encourages muscle growth. Long distance runners do not experience this increase, and the opposite happens. These athletes have an increase in cortisol, which is a hormone related to stress that is catabolic in nature and tears down muscle tissues for energy. When you sprint your body uses glucose and you will burn off stored body fat for energy. Long distance running uses a different process that relies on muscle glycogen that has been stored and these tissues are broken down rather than being built up. During extended periods of activity the glycogen stored in the muscle tissues will be converted into glucose for energy, and fatty acids are also released from various cell types. Sprinting will give you better results if you are trying to bulk up and get massive muscles because this activity provides full body conditioning and encourages growth of muscle tissues. Runners who go for long distances tend to reserve some body fat and will eventually break down the muscle tissues. These athletes tend to be slim and have little visible muscle while sprinters can gain huge muscle mass with shorter but more intense workouts. There is less fiber damage, repetitive stress, and tissue breakdown with sprints so you can get ripped faster with less workout time.

Source

http://outlook.monmouth.edu/index.php/lifestyle/368-distance-vs-sprints

http://www.livestrong.com/article/466121-does-running-a-long-distance-burn-muscle/