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Destroy Plateaus With A.C. Sprints

bodybuilder running

The advanced training technique I want to share with you this month is one that you may not associate with bodybuilding—if you know about it at all. Two columns ago I discussed the lactic energy system in regard to barbell clusters, but this month we’re going to focus on increasing the capacity of your alactic system.

Alactic-capacity sprints are part of a system called energy systems’ training, which is exactly what it says—training specific to one of the body’s three energy systems. Even if you haven’t heard the term “energy systems’ training,” you’ve certainly heard the term “conditioning,” and they’re actually the same thing.

We don’t talk a lot about conditioning in the bodybuilding world, and that’s too bad because it’s a necessary component of every program. To understand why, you need to have a basic understanding of the energy systems and how they work.

Energy Systems 101

The human body has three separate energy systems, and each plays a different role in regenerating adenosine triphosphate, a.k.a. ATP, for muscle contraction. How well each of them does that depends on the duration of the exercise, the number of times it’s repeated and the length of the rest period.

The PCr/alactic energy system provides the first few seconds of explosive, immediate energy. PCr is phosphocreatine, which consists of one phosphate molecule and one creatine molecule, very weakly bonded together. Because that bond is so tenuous, the creatine releases the phosphate molecule very readily to help regenerate ATP. So, if trainees can regenerate PCr more quickly, they increase their alactic capacity. The PCr/alactic energy system produces enough ATP for only the first few seconds of output, roughly 10 seconds or less.

Next up is the glycolytic energy system. It produces ATP through glycolysis, and after the first 10 seconds of output it provides the bulk of the ATP for the rest of the exercise. It’s basically an intermediate energy source, though, as it produces enough ATP for only another couple of minutes or so.

Once the ATP from glycolysis is depleted, the aerobic energy system becomes the predominant energy source. When you’re working at a maximum effort, the majority of ATP produced through the aerobic energy system is produced during the recovery period.

What’s cool is that the aerobic energy system helps produce ATP in two ways: First, it directly produces ATP during low-intensity work or your rest and recovery time. Second, it produces more phosphocreatine to replenish the PCr/alactic system’s ATP stores.

Until fairly recently, everyone thought that these energy systems worked in that order. In other words, the PCr/alactic shut off and the glycolytic turned on, and when the glycolytic burned out, the aerobic came on. Now we know that they all start up the minute you lift that barbell or take the first step of a sprint; however, they each have a limited (but trainable) capacity. When one system reaches its capacity, the others take the lead.

Power vs. Capacity

Each energy system has a power component and a capacity component.

The power of an energy system has to do with how fast it can switch on and start producing ATP. Because the PCr/alactic system is the fastest, it’s the lead system for those first few seconds of explosive activity.

The capacity of an energy system is how long it can keep producing ATP at a certain level of energy expenditure—basically, the intensity of the work you’re doing. For instance, the PCr/alactic system can produce a ton of ATP during very intense exercise and do it very quickly but only for a really short time. There’s a reason that your one-rep max is your one-rep max and—that you can’t do a full-out sprint for a mile.

On the other hand, the aerobic energy system can sustain a fairly even level of ATP production but only during a low-intensity or recovery period.

Why You Need to Increase Your Alactic Capacity

Increasing the power and capacity of all of the energy systems improves overall cardiovascular health—but what do bodybuilders do? They put out very explosive, very intense, very short bursts of energy, and they do it repeatedly. By training to increase your alactic capacity, you stimulate adaptation that takes place on a muscular level as well as a neurological one.

All adaptation is a defense mechanism. You stress out your body by demanding that it complete an explosive, intense movement, so it rushes to develop more explosive power. Athletes who do alactic-capacity training have the most significant explosive power.

Alactic-capacity sprints increase your tolerance for lactate; increase your resting levels of ATP, phosphocreatine, free creatine and glycogen; and increase the size of your fast-twitch muscle fibers.

The upshot is that thanks to alactic-capacity-sprint training, you’ll be able to work at a higher intensity during those explosive movements or work for longer periods at the same intensity. In other words, you can train harder. As a side benefit, this workout provides an extreme metabolic stimulus, so you’ll burn fat as well.

How Alactic-Capacity Sprints Work

If you want to train for more alactic power, you focus on maximum intensity or weight—for example, an uphill sprint, a 1RM squat press or a medicine ball throw—with very short, incomplete rest periods between reps.

When you train to increase alactic capacity, you use less weight or less intensity—like a flat sprint rather than uphill—and you take a longer rest period between exercises, in order to give your aerobic system time to replenish your alactic system’s ATP stores. Still, you do as many of them as you can at each workout.

For instance, you might do 10-second sprints followed by 90-second rests.

The goal with alactic-capacity sprints is to keep the heart rate between about 120 and 150 beats per minute, both during your effort and during your rest period. That keeps your glycolytic system out of the equation, so that your aerobic system is producing more phosphocreatine and ATP.

What to Do Next

If you have a coach or mentor, talk to him or her about incorporating alactic-capacity sprints once or twice a week. Your coach can help you decide how to go about training by evaluating where you are right now as far as cardio fitness and your current alactic capacity.

If you don’t have a coach, I encourage you to check out our personal one-on-one coaching program at It’s just about at full capacity for the year, but registration is still open as we fill the last few spots. With our one-on-one coaching, you won’t just be learning about this and other advanced techniques; you’ll be using them—and sometimes you’ll hate us for it.

Editor’s note: Vince Del Monte packed on an amazing 40 pounds of muscle in 24 weeks. He’s known as “the Skinny Guy Savior” and offers a number of courses to help you go from twig to big, including No Nonsense Muscle Building. For more information or to sign up for his free-tips newsletter, visit www.VinceDel  IM

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