Getting Started Part 9- Energy Systems
We have already answered many of the basic questions related to setting up a strength training program, however we can not begin a comprehensive training program without a better understanding of conditioning programming. An understanding of the body's energy systems is the cornerstone for effective conditioning prescription. In this post, we will define the energy systems and how they relate to conditioning prescription.
The phosphagen, glycolytic, and oxidative energy systems all work simultaneously to fuel our performances. The intensity and duration of an activity dictates the proportion of contribution from each energy system. The table below outlines the approximate durations and corresponding intensities associated with each of the energy systems.
The phosphagen energy system gets to work at the onset of exercise, and helps us to power high intensity activities such as strength and power training, sprinting, or any maximal effort task. This system is easily exhausted within 10 seconds of all-out activity and may take as long as 8-10 minutes before it is able to nearly fully replenish itself. When performing maximal intensity sprints, work-to-rest ranges are optimal in the area of 1:12 – 1:20. The closer to maximal effort your sprints are run, the fewer number of quality repetitions are possible in a workout. Depending on your fitness this may only be one sprint, or it may be 10 sprints. Let your running performance dictate prescription. Once you feel that your sprint performance is significantly slower than your fastest repetition, it is a good sign that this energy system and/or your neuromuscular system is spent. Shut down the training session and save your efforts for your next workout.
While the phosphagen energy system fuels our maximal efforts, the phosphagen and glycolytic sytems combine forces to fuel very hard efforts for up to 30 seconds. Beyond 30 seconds and out to 2 minutes, the glycolytic system takes over and provides the energy for hard efforts. Sprints that tax the glycolytic energy system can arguably be the most uncomfortable training an individual can perform. We burn through our stored carbohydrates and as a result produce high levels of lactate. The accumulation of hyrdrogen ions and inorganic phosphate causes the burning sensation that all trainees grow to hate. Work-to-rest ranges are optimal in the area of 1:3 – 1:5 when training the glycolytic energy system. Performing one to three workouts per week that tax this energy system provides an adequate stimulus for improvement. Too many weekly sessions can lead to overtraining in a hurry.
The glycolytic and oxidative systems power moderate efforts lasting 2-3 minutes, and the oxidative system fuels any low intensity efforts lasting longer than 3 minutes. Optimal work-to-rest ratios range from 1:1 – 1:3. A powerful oxidative system is necessary for long, slow endurance events, as well as enhancing recovery between intense anaerobic bouts. The body can endure numerous weekly sessions spent training the oxidative system. However, it is critical to properly progress training volume or overuse and stress related injuries can became a real risk. The study of proper training progression is known as periodization, which we’ll cover in our 10th and final installment of the Getting Started Series.
Next up in the Getting Started Series, Part 10- Periodization