By Stefan Ianev
Over the last two installments of the ‘Train Like A Pro’ series, we have looked at exercise selection and volume as part of the seven acute training variables. To recap beginners should generally perform 3-6 sets per body part per session, done over 1-2 exercises. Intermediates would typically need about 8-12 sets done over 2-3 exercises. Advanced trainees for the most part would need 12-16 sets done over 3-4 exercises. On occasion advanced trainees can go above this during an over-reaching phase to force further adaptation when they have plateaued, followed by an unloading period for super-compensation to take place.
This week we are going to take a look at the role of intensity as part of the equation when it comes to eliciting fat loss and hypertrophy goals. This is an area I focus on extensively with the personal trainers at our Sydney CBD and Chatswood gym’s. This is also an area that our certificate 3 and 4 in fitness students will learn as they certify to become personal trainers with the Clean Health Fitness Institute.
In strength training intensity is simply defined as the percentage of your 1 rep max. In other words the closer you work to the absolute maximum load you can lift, the higher the intensity. We can call this absolute intensity. So if I were using 70% of my 1RM my absolute intensity would be 70%.
Equally important however is the relative intensity at which you work. Relative intensity can be defined as your perceived effort in relation to your maximum effort for any given set. Relative intensity is typically expressed as an RPE or Rating of Perceived Exertion Score. An RPE of 10/10 is considered a maximum effort. This is termed Repetition Maximum or RM. So if I was using 70% of my 1RM for 12 reps vs 10 reps, the absolute intensity would be the same but the relative intensity would not. This is an important distinction to make, as both will be discussed.
In terms of absolute intensity it is generally accepted that 1 to 5 reps at 85-100% of 1RM is best for developing strength, 8 to 12 reps at 70-80% of 1RM is optimal for hypertrophy, and 15 or more reps at less than 70% of 1RM is for developing muscle endurance.
Keep in mind that the repetition maximum at any given intensity can vary greatly from one individual and to another, and for different muscle groups within the same individual. This is due to differences in specific muscle fibre make up. Recent research however has shown that similar hypertrophy can occur in rep ranges from 3 to 30 reps provided a minimal volume and intensity threshold has been reached (1-5). This is likely due to fibre specific adaptations and selective fibre hypertrophy as supported by some recent studies (6-9).
Tension appears to be the primary driver of hypertrophy in the high threshold fibres while TUT and metabolic stress seem to cause greater hypertrophy in the slow twitch fibres. This is because slow twitch fibres have greater endurance capacity and take longer to fatigue, while the fast twitch fibres are capable of generating more force. So the hypertrophic adaptations should be looked at on a broad spectrum from tension to metabolic stress.
Training in the 8 to 12 rep range as typically recommended for hypertrophy will give you a good base of tension and metabolic stress because it falls in the middle of the spectrum, however training with more, or fewer reps may be beneficial for maximizing adaptations at either extreme.
Some of the greatest champions from the past like, Arnold, Reg Park, Franco Columbo, and Ronnie Coleman not only carried and enormous amount of mass but they were also incredibly strong. They build superhuman strength and dense muscle mass from hoisting heavy iron for low reps. In fact they all started out as weightlifters or powerlifters which they attributed to building their foundation or base, and even later in their careers they never fully abandoned heavy lifting often working up to triples, doubles, and on occasion even singles.
Heavy lifting not only increases strength of the muscles and tendons, but may also cause greater hypertrophy in the fast twitch fibres, which are denser and give you a harder and denser look. Heavy lifting however can be very taxing on the joints and nervous system and needs to be cycled appropriately.
On the other hand many greats including those mentioned above have also done reps well in excess of the typical hypertrophy ranges. Reps of 30, 50 and even 100 or more have been performed by some pros using straight sets, dropset, supersets, trisets, and giant sets to fully engorge the muscle with blood which leads to increased mitochondrial density, greater fat burning capacity, and slow twitch hypertrophy.
In fact studies show bodybuilders have greater slow twitch hypertrophy than powerlifter and weightlifters that perform fewer reps (10), which could explain the extra muscle mass they carry, and why they are more vascular and look more conditioned. For beginners my personal recommendation is use between 10 to 15 reps per set. Since the early adaptations are largely neuromuscular and anatomical there is really no point in going below or above this.
For intermediate and advanced trainees the rep prescription will vary depending on the phase and the persons muscle fibre makeup. For the most part during a mass gain phase I recommend 70% of the work to be done in the 6 to 12 rep range. Then 15% of the time doing fewer reps, and the other 15% of the time doing more reps, during a cutting phase when we are chasing more metabolic adaptations I recommend the majority of the work to take place in the 8 to 20-rep range.
In term of relative intensity I recommend going to repetition maximum only on the last set of an exercise. Once you hit failure performance on subsequent sets is greatly impaired. This is due to both central and peripheral fatigue, which hinders high threshold motor unit recruitment. Going to failure on every set will greatly cut into your overall volume and frequency.
In fact if you watch most pros train they typically pyramid the weight up every set even when the reps stay the same. This not only warms the muscles up but also primes high threshold motor unit recruitment. When you fatigue the low and intermediate threshold motor units in those earlier submaximal sets your body is forced to recruit the higher threshold motor units in the later heavier sets.
Even Dorian Yates who was a well know HIT advocate would do 3 primer sets and 1 all out set for each exercise. He would typically do 3-4 exercises per body part so he was still getting a good 12-16 total sets. This is very similar to how most of the other pros train but he just didn’t count the primer sets even though he was still getting the work in. Those lighter sets still contributed to warming-up the muscle and fatiguing the lower threshold motor units.
Depending on the program, the phase of training, and the clients training age I typically recommend either pyramiding the weight up to maximum load set, or doing multiple sets with a sub maximal load and reaching failure on the last set due to cumulative fatigue.
Both systems have their advantages, which we discuss as well as their proper application in our CHFI Performance PT Level 1 Certification.
Stay tuned for our next installment when we discuss type of contraction!
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