Specificity of Range of Motion for Strength: Does it Pay to be a Jack of All Trades?
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TRAINING TAKEAWAY: Strength gains are generally specific to the range of motion trained. However, there’s some evidence that training through a shorter and longer range of motion may each offer unique benefits for strength. The former allows for greater absolute loads to be lifted while the latter is likely to lead to greater muscle growth per set.
Background
There has recently been a lot of discussion surrounding the topic of range of motion (ROM). This discussion has centered around muscle growth, and this is for good reason. Emerging evidence suggests training some muscles at longer lengths improves hypertrophy outcomes. Check out podcasts we did on this topic here: 1, 2.
I haven’t seen as much discussion on this topic for strength gains. A few years ago, many lifters would perform “overloading” movements that shortened the ROM, allowing the use of heavier absolute loads. It seems that this style of training has fallen out of favor and a more specific approach has been adopted. I think this is a good change, but we should be wary of the pendulum swinging too far in one direction and ignoring potentially useful tools.
Research Overview
A recent preprint meta-analysis by Wolf et al. demonstrates why a shift to a more specific approach, on average, makes sense. The authors compared strength gains between groups with varying ROM’s. To simply state what the author’s found - strength is specific. If you want to be strong in a given ROM, train in that ROM. This is shown in a subanalysis that examined “biased” strength outcomes, meaning the strength test was similar to the way one of the groups trained. For example, if full ROM squat 1RM is measured, the group training the full ROM squat would be the “biased” group. On average, greater strength gains were observed in the “biased” groups. On the surface, this indicates that training for strength should always be done with the ROM you want to get stronger in.
While training with a specific ROM for strength is a good rule of thumb, this analysis does not indicate whether there is a unique benefit to mixing ROM’s. So, the next question is whether performing all training in a specific ROM is superior to approaches that allocate some but not all training to non-specific ROMs.
To gain further insight here, I collected all the studies from the Wolf et al. meta-analysis that compared a “only specific ROM” to a “mixed ROM” approach for measures of strength that most resemble outcomes evaluated in strength sports. Below is a table of the studies that meet this criteria. In all of these studies, the “mixed ROM” groups performed some sets with a shorter ROM.
When pooling these studies into an overall effect size estimate, it sits dead center at 0.00. At face value, it may seem like there isn’t much going on here.
However, there’s a few considerations to discuss. Taking a step back, consider this trend that mixed ROM approaches aren’t worse. This may indicate there are at least some reasonable applications of non-specific ROM training. Moreover, the majority of the studies lean in favor of mixed ROM approaches, potentially indicating positive effects with certain applications. Further, both of the studies that show effects in favor of only specific ROM come from the same lab (1, 2). Since each lab will often use unique procedures, it warrants a quick mention of their methods. In these studies, it’s not entirely clear if the mixed ROM groups were able to take advantage of the ability to lift heavier absolute loads with the sets at the decreased ROM. Without increasing the load to compensate for the decreased ROM, these protocols become less relevant to our specific question. If these studies do not allow the mixed ROM groups to use appropriate loads for their partial ROM sets and were omitted from our collection of studies, the overall effects would be in favor of a mixed ROM approach.
Overall, it seems that specific ROM training is superior to non-specific ROM but only specific ROM is not superior to mixed ROM training. Thus, there may be a benefit to some non-specific ROM training. I have a few speculations:
Handling heavier loads may have psychological benefits. If a lifter has handled the weight before - even with a partial ROM - they may be able to avoid excessive anxiety prior to a PR attempt.
There could be adaptations in the musculotendinous unit and the nervous system from greater absolute loads. Adaptations like tendon stiffness, connective tissue alterations, muscle architecture, voluntary activation, and rate of force development could improve maximal force production for relevant joint angles.
It may simply train joint angles that “modify” rather than “drive” 1RM strength. A failed lift typically occurs around the individual’s “sticking point.” Force production right before the sticking point is likely the best predictor of strength. However, improving force production outside of this ROM may still contribute to strength.
This is analogous to a rocket being sent to outer space. The best predictor of the rocket’s maximum distance is likely the size and strength of the engine, just like the best predictor of strength being force production right before the sticking point. However, the size of the engine is not the only factor that plays a role in the distance a rocket can travel. Factors like the materials of the rocket can meaningfully modify the rocket’s performance. Similarly, strength at non-specific joint angles may “modify” rather than “drive” 1RM strength.
Practical Applications
As mentioned, strength is specific, and this applies to the ROM trained. For the majority of strength training, it's probably a good idea to train in the ROM of the task you want to improve. That said, there may be unique benefits to dedicating some of your training volume to longer or shorter ROM variations. The following guidelines may apply:
Perform some variations that have greater ROM than the lifts that you want to improve strength in. This could result in more efficient muscle growth, benefiting long-term strength development.
Experiment with variations that have a shorter ROM than the lift you want to improve strength on. Handling heavier absolute loads may provide a unique benefit for strength development.