Intensity Techniques – Partial Reps with Coach Mark Carroll

Intensity Techniques – PARTIAL REPS

Jul 30, 2022
Mark Carroll

I LOVE intensity techniques! So far I have covered two of my staples – the “rest pause” method and “drop sets.” These are both more traditional ways to program to extend a working set. Partial reps are a touch different and I would say a more advanced strategy surprisingly to most people, due to performing in such a fatigued state. But, I am getting ahead of myself. Let’s go over the basics of partial reps. 

What are partial reps? 

Partial reps are in reference to performing a rep with less than full range of motion. This does not mean you perform all reps of the set as partial reps. Rather, partial reps are utilised when fatigue is high and full range of motion reps can no longer be achieved. A partial rep is a technique we can use to extend a working set. When you can no longer achieve a full range of motion rep, you have two options. You can stop the working set. Or the second option is to continue the working set but with a rep range you can utilise to keep the set going. This is why partials can be a good strategy to take a muscle to and past full range of motion failure. Just because a full range of motion rep can no longer be achieved due to fatigue, does not mean the muscle fibres can no longer keep being recruited and trained in the working set. 

An example of a partial rep as an intensity technique would be on an exercise like a leg extension. A leg extension has the greatest tension towards the top of the movement when your legs are fully extended. This is where the peak tension will be on the quads. The bottom range of the rep will be where tension is lowest. When you fatigue on a leg extension it will not initially be at the bottom of the rep; you will struggle to finish the top of the rep when the legs are extending. 

This makes sense as tension is highest at the top of the moment. Therefore the top will be most challenging and logically harder to finish the rep. But, this is where a partial rep strategy can be effective, as for the majority of the range of motion of the movement you still have muscle fibres that can be trained. It’s the very top portion where the quads are fully shortened which is fatigued. The idea of partial reps is to continue with the range of motion you still have available. 

Let’s say you cannot complete a full rep but you can make it 95% of the way up. The final 5% you cannot complete. This will be where a working set will commonly end. What if you instead continue the set with the range of motion you still have available? You cannot do a full rep, but can you do the next rep and complete 85% of the rep? Cool, let’s do that! Then the next rep you can complete 75% of the range of motion, then the next set 60%, etc. Each subsequent rep will have a drop off in the range of motion you can complete as fatigue continues to accumulate. 

The idea however is through the use of a partial rep, you are continuing to push the muscle fibres being trained in that movement pattern through whatever range it still has available. 

What exercises to use this intensity technique on? 

Now, this is important. Not every exercise is a great fit for intensity techniques. Especially, that of a partial rep method where you are truly trying to take a set to and past failure. Exercises like squats and deadlifts should be obviously, I hope, movements you would not utilise this strategy for. Technique breakdown is too great when in such a fatigued state. This can lead to injury. Rule number 1 – don’t hurt yourself in the gym! 

However, not all machine exercises are the best fits for partial reps. The movements I like to use for the partial rep intensity technique, will be exercises which are hardest in the shortened position. Like a leg extension! 

An exercise which is hardest in the shortened position means the exercise will have its greatest resistance during the movement in the range of motion where the muscle is shortening. 

Think leg extension, lying leg curl, lateral raises, dumbbell spider curls,  triceps cable extensions and hip thrusts. These movements are all going to be hardest at the top when the muscle is fully shortening. These are the exercises which make the most sense for partials as they will allow you to still achieve a large range of motion on the partial reps. 

Take an exercise which is hardest in the stretch position. The bottom position when the muscle is fully lengthened. As an example, let’s use a seated leg curl which is opposite to the lying leg curl. The seated leg curl is hardest in the position where the legs are fully straight. This is the starting position. When peak tension is here, at the beginning of the movement, when fatigue sets in, partial reps will be very hard to achieve, as the starting position is hardest. Partial reps are meant to allow you to extend the working set. Performing them at the range where it is hardest does not make sense. 

Now, a lying leg curl will have tension greatest at the top. This means the rep begins in a lengthened position. Then only at the very top is the movement going to be fully fatiguing initially. Due to this, it means partial reps can be utilised on a much larger range of motion as compared to the seated leg curl. You can take the rep most of the way up despite high fatigue. 

Then as fatigue accumulates, the range of motion will lower for each rep but we can still achieve a nice range for the majority of the 3-5 partial reps! 

When to use partial reps? 

Partial reps are a tool to take a set to all out failure and beyond. For this reason, we want to use this technique sparingly. High fatigue is associated with pushing to all out failure. We don’t want to be using this technique every set of every workout. 

Ideally it will be utilised on the final set of a working set only. Then only from time to time. NOT every single week of a program. 

Then finally, use partial reps on exercises which are safe to push to failure like a leg extension and lying leg curl! 

Partial reps are a fantastic tool, but like all intensity techniques, you need to use the right tool for the right job. 

Use wisely!

Coach Mark Carroll