Today, especially among the most hardcore bodybuilders, we witness the proliferation of training methods: what role do you attribute to the use of techniques such as supersets, stripping, rest pause etc?

I don’t think they serve a valuable role at all. These techniques are typically done to fatigue and damage a muscle group past the point of failure. The first problem is that fatigue and muscle damage are not the root of muscle growth, but rather progressive tension overload over time. Secondly, it is very difficult to track progress when using these types of techniques, and for advanced bodybuilders, especially natural bodybuilders, muscle gain is a slow process, so it’s best to track improvements in training strength (for example five rep max) over time, rather than a physique specific measure. Supersets, strip sets, etc don’t allow for good tracking of progress.

There is a technique superior to another for the promotion of hypertrophy?

Great question. If we realize that damage and fatigue aren’t the roots of hypertrophy, but rather progressive tension overload, then we have to ask what aspect of resistance training best promotes this? Well, using a heavy enough load, and performing an adequate volume of work to promote muscle fiber hypertrophy is the key. That means, we need to using loads in the 1-15RM range for the vast majority of training, and using techniques that don’t hamper one’s ability to perform. So for example, instead of going to failure on multiple sets for multiple movements for hte same muscle group, you might stay 1-2 reps shy of failure on all sets except for the last set for that muscle group so that you are able to accomplish more total repetitions in that session with a heavier load. For example, doing bench press and going to failure if your 10RM is 200lbs might mean you do 200 x 10, 7, 5. However if you stopped 1 rep short and had less fatigue, you might do 200 x 9, 9, 9 hitting failure only on the last set. In the first example, 22 reps are achieved, in the latter, 27.

One way to do “supersets” without hampering volume, is to do opposing muscle groups. For example do 1 set of Bench press, followed by 1 set of Row. This way one muscle group can rest while the other is trained, it allows you to still be time efficient but not to harm performance. In fact, a few studies suggest it can even prime the other movement and increase the number of reps performed. A good recommendation would be to complete 1 set on the first movement, rest at least 30-60 seconds afterwards, and then complete 1 set on the opposing muscle group movement, and then rest at least 30-60 seconds again before starting on the 2nd set for both muscles. This ensure you both recover, and still get a priming effect that may increase total volume.

What role do you assign to the coupling of these techniques consecutively in exercise? (for example: 10 superslow shots in superset with one or other techniques)

There is absolutely no reason to do superslow sets. Purposely slowing down the speed that repetitions are performed forces you to reduce load, which also reduces volume as volume is sets x reps x load. Time under tension is not the only variable that is important, but also the magnitude of tension. We are on the planet Earth every second of our lives, resisting gravity, so therefore we are always under tension, yet we don’t continue to grow. Thus, we understand that the magnitude of tension must be high enough to optimise growth. Yes, we should use full range of motion and good form, and the load should not be so heavy as to compromise this, but if you have to reduce load because you are training purposely slow, that’s too slow.

How important is intraset stretching and what is it only a myth?

Static stretching has been shown to decrease subsequent force output acutely, which you wouldn’t want to do while lifting, dynamic stretching does not and can even prepare muscle to perform, so the only stretching I would recommend would be a dynamic warm up prior to training.

Stretch induced hypertrophy is a real thing, but it’s a different type of hypertrophy and potentially disadvantageous for the goals of a bodybuilder (it makes muscles longer not necessarily thicker and larger), especially if it means stretching a muscle-tendon unit between lifting sets which could potentially harm performance.

Bodibuilders often try to find the right exercise to isolate a muscle sacrificing the load, that could be given instead to more engaging exercise. Do you believe that this way can be a valid approach?

Bodybuilders should primarily focus on compound multijoint lifts that train multiple muscle groups, as this is an effective and time efficient way to overload a lot of muscle at one time. Once this is done, then they can move onto some "isolation "exercises to ensure proportionate development, but the majority of training time should be dedicated to compound lifts.

A question that divide bodybuilders: how much important is strenght development for muscle development?

Progressive tension overload is critical for continued muscle growth. What your 1 repetition maximum is doesn’t matter, but if you are lifting the same loads that you lifted 3 or 4 years ago in your 6, 8, 10 or 12 rep sets, you are likely a similar size and haven’t grown. Neurological strength adaptations are in many ways permissive to further muscle growth, and vice versa, so while primarily a bodybuilder should focus on training with an appropriate volume for their current level of development, improving strength over time is essential to avoiding stagnation in a long term career.

What is, if any, your recipe to communicate to all pumping iron fans to build a proper workout?

If you don’t know where to start, and you are a novice or intermediate bodybuilder or aspiring bodybuilder, set up a split where you train each muscle group 2-3x/week. Then, in each session, do roughly 40-70 reps for that body part, each time it’s trained that week. Make sure your loads are appropriate, with most of your training occurring in the 6-12 rep range 1-2 reps shy of failure. We are fortunate enough to have a fairly large body of evidence that suggests this is more likely than not, an appropriate range to optimize hypertrophy for early stage lifters. Then, simply focus on trying to gradually increase the loads you handle over time to get continued growth. Focus primarily on compound movements, and sprinkle in accessories to round things out.

The importance of including high volume excercises to ave lactic acidosis: myth or reality?

Metabolic fatigue is a secondary mediator of hypertrophy at best, and shouldn’t be the primary focus of training. Some "isolation" work in the 12-15 rep range after doing your moderate and heavy load compound lifts is a good way to get in volume on bodyparts that are lagging though, and certainly the final set for each muscle group can be taken to failure.