New Research Reveals the Ideal Proximity to Failure for Maximum Muscle Growth
The idea of pushing ourselves to failure in our training may be a foreign concept to many. After all, grunting and screaming at the end of our sets is usually reserved for Schwarzenegger-esque bodybuilding spaces and might not suit our local Globo gyms so well.
Moreover, research over the past few years has shown that we don't actually need to train to failure to see muscle growth – in fact, stopping 2 or 3 reps short is sufficient. Further research indicates that even being 7 reps short could be enough, but how does that hold up against all the evidence we have available?
The Study
The aim of the study, published in the Journal of Strength and Conditioning Research, was to compare the effects of 2 velocity-based resistance training programmes when performing resistance training with matched training volume.
The Methods
The methods included:
10 experienced lifters with an average resistance training experience of 4.5 years.
A within person, between leg design was used with the same training loads.
Leg press and leg extension were trained unilaterally twice per week over a period of 9 weeks.
For each participant, the legs were randomly assigned to either fairly close to failure, at 30% velocity loss and 14 reps per set, or the other leg trained far away from failure, at 15% velocity loss and only 7 reps per set.
Before and after the intervention, both legs were tested in 1 rep max, maximal voluntary contraction, rate of force development, average velocity, and power output, and 75% of 1RM (all in unilateral leg press).
Muscle thickness and size was measured.
The Results
The findings included no differences between the legs in any of the variables. Both low and high velocity loss were effective for increasing 1 rep max, maximal voluntary contraction, power output, and muscle thickness.
What Does This Mean for Us?
One of the major limitations of this study is the small sample size of just 10 participants. Additionally, there could be an element of cross-education between limbs occurring. Therefore, this isn’t a study from which we can draw meaningful recommendations in isolation. While that doesn’t make the study irrelevant, it does mean we need to consider additional research to draw solid conclusions in conjunction with this one.
Another study examined the effects of single-set resistance training performed to muscular failure versus training with 2 reps in reserve (2 reps left before failure) on various muscular adaptations. Both training groups achieved significant muscular adaptations.
Similarly, a review published in the Journal of Sport and Health Science established that trainees who did not train to complete muscular failure – but trained close to it – experienced similar increases in muscular strength and size as those who did.
We hate to be the bearers of bad news, but if you want to be certain you'll achieve muscular gains, the 'sweet spot' for ensuring growth seems to range from 0–5 reps from failure. This essentially means that as long as you don’t stop with more than 3–5 reps left in the tank, you’ll be golden.
While the previous study suggests stopping further short of failure can still deliver gains, achieving muscular adaptation requires experiencing a certain degree of discomfort. The key stimulus for muscle growth is muscular tension, and as you complete more reps, muscular tension increases. Therefore, while more evidence is needed to confirm that stopping 7 reps short of failure is enough, pushing out a few more reps will help seal the deal when it comes to muscle growth.
You Might Also Like
