Alactic System

The alactic system (also known as the ATP-PC system) is a fancy name for the body's primary energy system used during short bursts of intense activity—sprinting.

It relies on stored ATP (adenosine triphosphate) and phosphocreatine (PC) in the muscles to produce energy quickly.

The key feature of the alactic system is that it doesn’t produce lactic acid and is used for very short-duration efforts—typically lasting about 10 seconds or less, and the best way to train it is not the sprint itself.

To effectively train the alactic system, focus on exercises that maximize muscle output while minimizing tendon involvement. Sprinting at top speeds engages the tendons heavily, which we want to reduce in favor of directly targeting the muscles.

Instead, incorporate resisted sprints, hill sprints, or bike sprints for short, explosive efforts (10-15 seconds max). These alternatives emphasize muscle engagement and minimize tendon involvement, allowing you to isolate muscle power:

• Air bike sprints may be the best choice. Sprinting on a stationary bike for 10 seconds with maximum effort, followed by full recovery, lets you target the muscles for highest power output possible.

• Heavy resisted sprints (e.g., sled/car pushes or pulls) are more effective than lighter alternatives, as they force your muscles to work hard while keeping tendons out of the equation.

• Hill sprints are a great replacement. Stairs also work.

• Lifting with resistance bands - If we overlook other benefits of this training, the key here is that you can do repetitions faster because the weight is being pulled down with gravity + bands.