Aside from building a solid foundation of strength, developing lower body power endurance is about as straight forward as it sounds, and usually revolves around how long an athlete can perform explosive jumps with moderate output before fatigue demands that they stop. In the weight room, I have really come to like using “power endurance clusters” with the safety bar back squat for building this quality, and this is because the safety bar does two great things.
The first is that, compared to a traditional barbell, the safety bar has the hands held at the front of the body. This bypasses the need for the shoulders to remain in external rotation for long periods of time and avoids both cramping of the joint as well as low back discomfort – as the two are intimately related. This is because when the range of motion of shoulder external rotation is limited – or fatigued – the natural lordosis (the curve in the low back) is increased to make up the extra distance that the shoulders cannot. This presents a large problem for many athletes in power sports, as high volumes of sprinting and jumping can already increase this curvature.
The second thing we get from the safety bar is the constant slow-twitch, aerobic stimulus that comes from standing under external load and which serves as an effective form of active rest. Let me explain. The clusters divide extended periods of work (60s-120s) into mini-sets of explosive reps (10s-20s), and each mini-set is followed by a brief rest period. The work creates a build-up of lactate, and during the rest period the lower body muscles must remain aerobically active to support the weight of the bar. This trains the fatigued muscles to recycle the lactate produced from the previous bout of work more efficiently, turning it into usable energy that can continue to power the mitochondria through the lactate – pyruvate – Acetyl CoA reaction.
This creates a perfect scenario to develop the desired adaptation, as during sport, the athlete must remain aerobically active between intermittent bouts of anaerobic work, and the safety bar comes with a far reduced orthopaedic cost than would occur with the traditional barbell. When programming the power endurance clusters, depending on the sport, I like to use three to four total sets, each divided into two to five mini-sets, and with rest periods that create either an equal, slightly positive, or slightly negative work-to-rest ratio, and to perform the clusters twice per week, increasing the number of mini-sets every other session.
