A study from 2017 looked at the recovery from a session of high-volume lower load (so eight sets of 10, at 70% of one rep max) resting at 75 seconds between sets, versus a lower volume, high-intensity group which was 8 sets of 3 reps 90% of a one rep max, resting 3 minutes between sets.
It looked at soreness, markers of recovery, strength recovery, muscle damage, inflammation, all these biomarkers. They found what most people would expect: the high-volume session caused a lot more damage and inflammation, it took longer to recover from compared to the high-intensity session. These findings may or may not be surprising to you.
Essentially, the lighter weight group had more muscle damage. Now some may think: “that means they had better muscle growth”, but that is not necessarily true. Muscle damage is not always equated to muscle growth. Now there are some benefits to muscle damage and inflammation in terms of the repair processes, but to completely associate muscle damage with muscle growth is not correct. Moreover, there are places in your training for both high intensity and high volume.
Of all the parameters that associate with muscle growth, volume (which is the number of sets multiplied by the number of reps multiplied by the weight) is most closely associated with muscle hypertrophy. Despite that, you still want to progress on the minimum volume that you can make progress on, for a few reasons. If you do a session that is so difficult and so muscle damaging, it will negatively impact and actually may impede the overall volume that you can have in a training cycle. Take for example, if the study would have done 5 sets of 8 with the same 70% of one rep max, perhaps these people could have recovered 30-40% faster. Therefore, they could have more sessions where they could do more weight with more volume overall, over the course of several weeks, and have a greater overall growth
response. Compare this to having one session that is a killer, then they might be so wrecked that they can’t effectively train for the next week.
Another aspect to consider is that high volume is relative to the individual, so high volume for a beginner might be 4 sets a week for say a squat. For someone who has been training for years, 25 sets a week might be high volume for squats. It all depends on what your training status is, how advanced you are, and the kind of volume dosage that you require to make progress.
However, you do not always want to add volume for the sake of adding volume. A study looked at German volume training (the closest thing associated with growth), where participants did 10 sets of 10. At the end of the workout, they were so wrecked that they did not recover well. They actually found the people doing 5 sets actually had better results. This was not because volume is inherently bad, but because the volume they did was so extreme that they could not recover for subsequent sets and their workouts became ineffective.
Always keep in mind that you are just looking at one individual training session, you must consider your overall training. You want to be high volume for you, but what is high volume for you is not going to necessarily be high volume for someone else, or vice versa. That being said, you never want to cross the line where volume is so high that it consistently negatively impacts recovery. If you cannot effectively recover from session to session, unless you are purposely overreaching (like how some Olympic lifters do) to get a better effect on competition day, but that is a short-term plan. In the long term, you do not want to have frequent sessions where the recovery is bleeding into your other sessions, for a few reasons. First, you increase the chance of injury because your form won’t be very good (because you’re so sore); and you’re not going to have very effective workouts because you’re so stiff and sore, and essentially burnt out.