Partial rep training, or using exercises with a limited range of motion, derives its history from old-school strength routines.
Paul Anderson, one of the strongest men ever and without steroids, found it useful. He would advance by increasing the range of motion, reaching enormous poundages in the full squat.
Many powerlifters use exercises within a restricted range. They include assistance movements such as high box squats, board or floor presses, and rack pulls. These aim to fix weaknesses for a specific movement or muscle group.
Does this popularity indicate that partial reps will work for you though?
Be wary of the lessons you think you learn when studying the elite. They have the best drugs and genes, giving them more flexibility in their programs compared with the natural, average trainee. You need to analyze what is truly responsible for their success.
Consider these reasons to avoid partial reps.
An investor should act as though he had a lifetime decision card with just twenty punches on it.
– Warren Buffett
- Tension is greatest in the middle of each joint’s range of motion.
This is the main reason to avoid partial rep training. It tends to emphasize positions where leverage is best but the muscles function weakly. This is the same flaw as accommodating resistance, which uses bands, chains, or machines to overload the top of a movement.
The parts within your muscle that bind together to create tension, allowing for a contraction that stimulates growth, start to overcrowd when a muscle shortens. Imagine the muscle bunched up like a ball of yarn, preventing optimal overlap. This position occurs near the lockout of the bench press and the squat, which many trainees focus on through partial rep training.
Though rarely emphasized, the stretched position is even worse. It has those parts spread too far apart and stresses the joints. You only need enough range of motion to allow for the development of power along with a stretch-shorten cycle.
Some research indicates that strength gains are specific to the range of motion used. This seems unlikely due to physiological reasons, perhaps having a neural cause. In the case that this may happen, consider that extreme ranges of motion under a load seldom occur in sports and life anyway. This may result in undesirable adaptations.
With a heavy enough load and medium positions on an exercise, the same muscle fibers work throughout the whole range of motion, only more or less weakly. Trainees only feel strong near the lockout since leverage gives them a mechanical advantage.
- It could be dangerous.
When using more weight than you could handle with a fuller range of motion, you may get hurt. Go beyond the specific range, without the safety features of a power rack, and you may lose control. This could occur though on popular exercises such as box squats, which bring other risks too.
The safest and best exercises are translatory. These are exercises that have you move in fairly straight lines. They are compound movements, applying the right forces to the involved joints. Slight deviation is fine though, providing one reason to use free weights over machines.
Muscles like the triceps and quads should not play more of a role near the lockout of a bench press or squat. This can occur with partial rep training due to non-translatory motion. In these cases, this would mean too much movement at the elbows and knees without enough at the shoulders and hips.
- It promotes variety.
Variety only seems to work since it creates new standards and resets the learning curve. Under its allure, you include poor exercises. This also tends to increase the amount of work by too much.
Partial rep training may work indirectly by allowing you to recover through less effective methods. It may motivate you by keeping your workout exciting. You will find it more fulfilling though to make great progress and have more time to spend on other things.
While some EMG studies do show differences in muscle activation between exercises, does it matter enough to support the risk? Unusual exercises will undoubtedly harm your joints.
This encourages a bits and pieces philosophy. You train specific muscles or portions of the range of motion through countless exercises. You add more and more instead of focusing on progress with less.
- It misleads you.
Many claim to feel more capable when they return to lighter weights for a fuller range of motion. Is this universal though? It can remind you of how difficult a heavier weight will feel.
Some experts claim that partial rep training builds up your connective tissue, yet this tissue can already handle far more than your muscles. It also cannot lift the weight for you.
An exercise like the rack pull allows you to hold a lot of weight, but does this really mean anything? What muscles are being overloaded?
Partial reps are often mentioned as more of a strength builder than for hypertrophy, yet the distinction seems unsupported.
- It may harm performance.
Partial rep training may change how you move when returning to a normal exercise. You could have negative transfer, or when new skills interfere with the original motion.
Partial reps typically bring less time under tension. In my opinion, this is not a major factor for building size and strength, but you still need some time to create the right kind of fatigue, however brief.
Most people find they apply far less effort with too little range of motion. It seems that enough time and space to develop power is important. Perhaps it also helps by providing a clear goal.
Partial rep training may harm your recovery for no real benefit.
Brief pauses at the lockout during a normal set may have its place. The stabilizing force in this position protects the joints despite the weaker muscle strength. This gives you a respite that reduces unrelated fatigue or even just prepares you mentally for a tough rep. The small cost in efficiency is probably worth it.
To prevent the abuse of these pauses though, you should avoid setting down the weight between reps.
Avoid Partial Rep Training
When investing, many people frequently buy and sell their stocks, similar to those that preach variety in training. These speculators may rely on elaborate math to justify their choices. They often follow the crowd, acting on the hot tip of the day or giving into mass panic.
A few do succeed, just as some do well enough on crazy programs, but most fail that go down these paths.
Think of every exercise as an investment. It makes sense to focus on the most productive and safe options. You want to think with an eye toward the future.
Consider the opportunity cost, or what you could do with the time, effort, and recovery spent on bad exercises. Evaluate the risks, which includes factors such as a higher rate of injury.
The reality is that training can be complex. You want to learn enough to avoid the big mistakes. You will discover that the best principles are simple and eternal.
So many methods will distract you from the goal of adding weight to your lifts. You must do this to build muscular strength and size. Improving in this way summarizes all of the complexity involved.
Humans have a tendency to complicate. This is not always for the better.
In fitness, we still have the same bodies that have evolved over thousands of years. The basics work best.
I suggest you put all of your effort into the bench press, the squat, and the row. Use a normal range of motion for them. Focus on these lifts, add weight over time, and avoid partial rep training.