Time under contraction

Is time under contraction one of the most important factors in strength development? ie. which scenario would increase max strength most successfully:
a) performing 1 rep close to 1RM 9 times with 5 minute intervals
b) performing 3 sets of 3 reps each near to 3RM

With each scenario, neural adaptions could occur depending on the athletes prior development, but I feel with b) the contractile proteins would develop moreso ie. greater beakdown priming greater supercompensation. I feel this due to greater soreness that occurs with scenarios such as b).

Similar sessions would be 3-5 x 3 or 3 x 5. Here I would gain greater DOMS with the 3 x 5.

Any comments?

It’s not that simple unfortunately. Repetitions possible at a given percentage of maximum are specific to the individual at a given point in time. If an athlete’s 3RM corresponds to 80% 1RM, singles would quite possibly be more effective. When repetition number decreases, relative intensity could be the same but absolute intensity is always higher. THis can increase neural adaptations but will significantly increase the risk of overtraining. I would recommend that if you’re 3RM is >87% you stick to 3’s.

THE most important variable is intensity. TUT is infact two variables: volume and tempo.

Determining Optimum Repetition Number

Research and practical experience suggest that a certain threshold of intensity (percentage of 1RM) must be breached in order to stimulate an increase in strength. There is however disagreement on the value of that threshold. Certainly, novice strength athletes can improve strength using loads as low as 60% whilst conversely, some Russian coaches do not log training loads below 80%!

The relationship between intensity and load is subject to wide inter-individual variation. Athletes with extremely high percentages of fast twitch fibres may only be able to perform 3 repetitions with an 80% load. Conversely, endurance athletes may be able to perform more than 30 repetitions at the same intensity. The relationship also varies for different muscle groups within the body due to differences in fibre composition*. The hamstrings for example have a higher proportion of fast twitch fibres than the quadriceps and hence greater reps are possible at 75% when performing knee extensions than when performing knee flexions (curls!). Finally, training itself can influence muscle fibre ratios hence the relationship is variable over time.

The relationship is not exactly linear. This may cause problems during programs that utilise different numbers of reps (see ‘Fallacies’ below).

Consider 75% to be the threshold for improvements in strength. An athlete can approximate the highest numbers of reps that should be performed in a given exercise as follows:

Maximum Reps = No. of reps possible at 75% 1RM

Test Limitations

Total time under tension is reduced by an increase in the speed of the eccentric action. This reduces the cumulative fatigue caused by each repetition and hence permits higher numbers of reps. It is necessary therefore that the exercise is performed strictly and that ‘cheat’ methods are eliminated.

Certain exercises do not safely allow the test because stabilising muscles fatigue before the prime movers. For example in pulling movements, the spinal erectors fatigue before the hip extensors.

Exercises that have a high skill component (e.g. Olympic lifts) are rarely performed in sets of greater than three reps. Fatigue negatively effects motor control and hence causes a break down in technique that increases risk of injury. Additionally performing reps under fatigue is detrimental to the development of optimum inter and intra muscular coordination. When performing exercises that limit the number of repetitions per set, decreasing recovery time and increasing the number of sets is a method of raising density (Tonnage / Training Time).

Common Fallacies

  1. Low reps cause overtraining

It is prolonged periods of high intensity (>90%) that cause overtraining. Low repetitions do not necessarily imply high intensities. Westside powerlifters for example, perform doubles at intensities as low as 60%. Also, as discussed previously; some athletes may have a 3RM of only 80%!

  1. Low reps do not cause hypertrophy

Low reps can induce significant hypertrophy providing total time under tension (TTUT) is sufficient. Consider the following two workouts:

  1. 3x8r @ 75% (180s recovery)
  2. 8x3r @ 85% (120s recovery)

The greater load in Workout 2 increases TTUT (due to slower movement velocities) and average muscle tension. Although training density (i.e. Tonnage divided by total time to complete sets), depending on recovery time, will be lower I would expect Workout 2 to provide the greater stimulus for hypertrophy.

  1. ‘Pyramiding’ is an effective training scheme

Pyramid training is at best an inefficient training scheme. The early high repetition sets fatigue the lifter prior to the heavier sets that require the most recruitment, stabilisation and motor control. Additionally, if the range in intensity is too great (>10%) there is insufficient volume at any one intensity to stimulate optimum adaptation. Finally, as mentioned previously, the relationship between intensity and the maximum repetitions possible is not linear, i.e. the increments between repetition maximums increase as the number of repetitions decreases (see above graph). The priority focus when designing programs should be to control intensity to protect against overtraining by using a ‘Buffer’ (see separate article). When using multiple rep patterns within the same workout, determining the magnitude of the buffer for each set becomes unnecessarily complicated. (the buffer also needs to increase as reps decrease)

  • I recognise that the terms ‘fast’ and ‘slow’ twitch fibres is a significant simplification

Couldn’t we divide the adaptations into two categories: 1) neural and 2) structural adaptations of the muscular system?

In that case, David has commented on 1, but regarding 2 I think Richard’s scenario b would be much more likely to induce structural adaptations. It would likely result in a greater quantity of degraded protein and a larger supercompensatory effect. This assumes the reps are performed as identical tempo for each scenario.

Why? Lets compare (A)5x3r against (B)3x5r.

TTUT is greater for A because, since the load is greater, the average movement speed will be lower. Also, since load is higher the stimulus for ‘structural’ adaptations is also greater. The only converse arguement is that density is lowered…

David, I understand what you are saying. I had meant to give scenarios controlling the variables better. How about the following where both scenarios involve 100kg (the athletes 8RM) with all reps performed with the same tempo (assume fatigue is a hyper theoretical nil for each set):

a) 3x5
b) 5x3

If tempo is identical: 3x5r because density is higher.

THis CT article explains it quite well:

Chronic adaptations to training simply mean that the structural adaptations to your training regimen will be relatively stable. At this point your body will be perfectly adapted to the training stress you are used to present to your body and thus it will not require further adaptation (read no further progress). At this point most peoples assume that their body has adapted to the exercises they are using and that’s why they change them around. Initially this will bring new strength gains but more often than not this is not correlated with added muscle gains. Why? Well the gains you get from switching exercises are mostly due to and increased neural efficiency at performing the new movement. In other words you initially get stronger in the new movement because you learn to be better at it! This has led peoples to believe that when they stagnate they must change the exercises around. This is erroneous in most cases (sports where relative strength and neuromuscular efficiency is the goal are another animal altogether!).

As it was stated your body adapts to stress - in our case physiological stress in the form of strength training. Your body will adapt itself to the stress placed upon it, not to the means which provide that stress. Your body doesn’t know if you are doing barbell curls or preacher curls, nor does it care to know about it! All that your body “knows” and need to know is that there is a physical stress x placed upon the elbow flexors (biceps brachii, brachioradialis, brachialis and the various forearm muscles). To make an oversimplification out of it, your body only needs the following information to start and modulate the adaptive response:

      1) What structures are affected by the stressor? 

      2) What is the magnitude, or importance, of the stressor on each of the structures? 

      3) What's the nature of the stress? 

      Obviously the structures affected by the stressor will depend on the exercise you use (chances are that a squat will cause more stress in the lower body than a bench press!) however because of the structure of your muscles, changing the exercises you perform for a specific body part will not lead to a great variation in the structure affected by the stressor (some recent research indicate that it might be possible to recruit different fibres with different exercises though). The only things that you can vary when you change your exercises around are the muscles involved. For example preachers curls are good to develop peaking biceps because this exercise will place most of the stress on the brachialis (placed under the biceps and which give the impression of a peaked biceps when overdeveloped) not because this exercise recruit different parts of the biceps which lead to the development of a peak. 

      Thus changing your exercises around can help resume your progress by working previously under worked muscles or by improving the neural factors involved in weight lifting performance. Both of which can be of benefit to athletes and bodybuilders. But once you have changed your exercises so many times that no muscles are under worked in relation to each other and that your nervous system is efficient in all the exercises you do you will not be able to kick start your progress simply by changing the exercises you use. 

      Probably the most important factor in triggering the adaptive response is the magnitude of the stressor. For easy comprehension's sake we will define the factors involved in the magnitude of the training stress: 
  1.  The tension produced (intensity) 
  2.  The total duration, or workload at which tension is produced during your workout (volume, either in it's time under tension form, or tonnage form  
  3.  The total load of tension (intensity x volume) per unit of time (density) 
       Muscle strength is exhibited by creating muscular tension. The harder a muscle needs to contract the more tension it must produce. So basically the heavier the resistance, the greater is the required muscular tension. For you scientific minds out there the higher is the muscle tension produced, the greater is the rate of protein degradation (which is one of the factor triggering growth stimulation). 
       If maximum muscle tension were the only factor involved in developing size and strength we would simply have to do singles in every exercises we do and grow like crazy! Unfortunately (or fortunately for some!) it's not the only factor involved. 
       The amount of growth stimulated is dependant upon the amount of muscle protein degraded during training. The more muscle protein are degraded the more your body will need to mobilise it's resources and the more it will "rebuild" the muscles to avoid such a stressful (pun intended) situation in the future! 
       The amount of degraded protein is a function of the rate at which protein is degraded (if you degrade 10x proteins per second you will degrade more protein than if you were to degrade 5x proteins per second all else being equal). And as it was stated the rate of protein degradation is determined by the importance of the muscular tension created. The other important factor involved in determining the total amount of degraded proteins is the duration of the degradation process. Obviously the more time you spend degrading proteins the more proteins will be degraded! This second factor is determined by the volume of training. 
       A third factor in modulating the adaptive response is the density of training. The more work you perform per unit of time, the more important will be the growth stimulation (this is mostly due to an increase in growth hormone production). 

So to resume. To stimulate muscle growth you need:

  1.  High tension contractions 
  2.  High total time under tension 
  3.  High density of training 

As we stated, tension is what is required to produce force. The more force needs to be produced, the more tension your muscles have to create. Now, force is defined as such:

F = MA

In which F means force, M means mass and A means acceleration. In other words you can either increase the force output by:

a) Increasing the weight lifted (lifting heavy loads relatively slowly)

b) Increasing the acceleration/speed (lifting light loads very rapidly)

c) Using an optimal combination of weight and acceleration (moderate loads lifted as fast as possible)

In regular bodybuilding training method a) is the only one currently used. Which means that bodybuilders are only stimulating 33% of the growth they could trigger if they used all three methods!

Increasing the weight lifted (lifting heavy loads relatively slowly)

The first method is already well known of most bodybuilders and powerlifters. It involves increasing the weight that one lifts. Basically there is two ways of making this work.

  1.  Keeping the reps relatively high and trying to increase the weight as often as possible 
  2.  Using low reps and very heavy loads 

It is generally accepted that point 1. Is the approach to use. We disagree. More weights = more force to be produced = more tension = more stimulation.

I know what you are thinking: “I’ve used low reps in the past, I got stronger but not bigger”. Maybe, but that’s because you forgot that muscle mass is stimulated via 3 factors (tension, total time under tension, density). So if you kept doing the same number of sets when using low reps as you did when you were using high reps you greatly diminished the total time under tension factor which probably negated the benefits of using very heavy weights.

Let us illustrate our point:

If one keep using the same number of sets

High reps: 3 sets of 10 reps with 120lbs for the chest, each rep lasts 4 seconds, the “workout” lasts 12 minutes (total volume: 30 reps, total tonnage 3600lbs, total time under tension 120 seconds, density: 300lbs/min)

Low reps: 3 sets of 3 reps for the chest with 200lbs, each rep lasts 4 seconds, the “workout” lasts 12 minutes (total volume: 9 reps, total tonnage: 1800lbs, total time under tension: 36 seconds, density 150lbs/min)


Total volume: -21reps

Total tonnage: -1800lbs

Total time under tension: -84 seconds

Density: -150lbs/min

So in this case using heavier weights will lead to less gain. However if we were to adjust the sets to keep the same volume:

If one adjust the sets

High reps: 3 sets of 10 reps with 120lbs for the chest, each rep lasts 4 seconds, the “workout” lasts 12 minutes (total volume: 30 reps, total tonnage 3600lbs, total time under tension 120 seconds, density: 300lbs/min)

Low reps: 10 sets of 3 reps for the chest with 200lbs, each rep lasts 4 seconds, the “workout” lasts 20 minutes (total volume: 30 reps, total tonnage: 6000lbs, total time under tension: 120 seconds, density: 300lbs/min)


Total volume: equal

Total tonnage: +2400lbs

Total time under tension: equal

Density: equal

In this case the second workout will obviously be more effective. When all other things are equal, the workout with the heaviest average weight will always stimulate more growth. Why? Simply because heavier weights increase the “M” in F = MA compared to lighter sets. So it is the premise of the HTT program that the first type of training to include is heavy lifting then adjusting the sets to have a high enough total time under tension to stimulate muscle growth.

Using an optimal combination of weight and acceleration (moderate loads lifted as fast as possible)

As we stated, Force can be increased many ways. One of the best ways to produce a high level of force and tension is to lift moderate loads in an explosive manner. The only movements that allow that type of training are the olympic lifts and their variations. These movements are by far the most powerful lifting movements that one can do and as an added benefit they involve most of the muscles in the body at the same time, with a special emphasis on the legs, lower back, upper back, traps and shoulder muscles. In fact look at elite weightlifters and for the same bodyweight they have the most muscular legs, back and traps or all athletes who train with weights (even bodybuilders). So it really is a wonder why bodybuilders have not picked up on it!

Well to be fair they DID pick up on it WAY back. When elite bodybuilders were still natural, the olympic lifts were a major part of their training. John Grimek who was considered to be the best-developed man before steroids was also a competitive olympic weightlifter (even went to the World Championships), Steve Stanko who won the Mr. Universe when the title still meant something was also a world class olympic lifter. Bodybuilding legend Reg Park (Arnold’s hero and model) regularly used power cleans in his training and I could go on and on.

When you look at the physique of these guys you’ll agree that it’s an example to follow for natural trainee.

“TTUT is greater for B because, since the load is greater, the average movement speed will be lower. Also, since load is higher the stimulus for ‘structural’ adaptations is also greater. The only converse arguement is that density is lowered…”

I think you mean TTUT is greater for A. Assuming you do, I agree with your comments re your scenarios but as I said I assumed tempo to be identical for each of the original scenarios.

Another question - which variable exerts the most powerful effect on structural adaptations - density (work/time), Total TUT, or TUT per set?

Yeah, I did. U 1 sharp SOAB :smiley: . BTW Sorry I missed your call last night, I 'm in tonight…

Another question - which variable exerts the most powerful effect on structural adaptations - density (work/time), Total TUT, or TUT per set?

Didn’t I just answer that?

5x3r @ 100k Vs 3x5r @ 100k

TTUT is (approx.) the same but density is higher for 5x3r, therefore density is more important.

Protealysis is a byproduct of training- not a stimulus to improvement and it should be avoided whenever possible.
Re Rate of adaptation:
While the answers are correct for stimulating the fastest rate of adaptation, is this the initial objective or would a more gradual adaptation (which would likely fit in well with the learning curve for lifts) ensure long-term viability of the tendon/bone structures?

No worries - I’ll try you again today. Right now I’ve gotta run (off to look for a job). Talk to you soon!

One other variable …

How does the speed of the eccentric phase affect the develpoemnt of strength in both scenarios - 3/5 or 5/3 ?

Is a slower ecc phase more likely to promote greater strength gains in the lower or higher rep sets?

When you say pyramiding is over estimated David is that not totally dependent on the degree of incline of the pyramid?

Would a very slight pyramid not be more beneficial than no pyramiding at all?

David, in 2 of your posts re. my 3x5, 5x3, you have shown both 3x5 and 5x3 to have greater density?

1)If tempo is identical: 3x5r because density is higher.

2)Didn’t I just answer that?

5x3r @ 100k Vs 3x5r @ 100k

TTUT is (approx.) the same but density is higher for 5x3r, therefore density is more important.

Sorry, sorry - just a typo. Definately 3x5r

When I asked whether TTUT, TUT/set or density is more important in stimulating structural adaptations, I didn’t mean to confine the discussion to the current hypothetical scenarios in which TTUT is identical.

In general, which variable exerts the most powerful influence on hypertrophy? I don’t expect that there’s an absolute answer, as obviously these variables are closely related and I would expect specific circumstances to influence their relative effects.

“Protealysis is a byproduct of training- not a stimulus to improvement and it should be avoided whenever possible.”

But proteolysis is a necessary step in the hypertrophy process. Aren’t there circumstances in which hypertrophy (and, by definition, proteolysis) is desirable? Are you arguing that hypertrophy is never desirable? Aren’t there cases in which hypertrophy increases an athlete’s power/weight ratio?

It is clear sprinters grow muscle, and this is not only SR growth but sarcomere growth (contractile protein growth) also ie. functional hypertrophy. Muscle breakdown or proteolysis is a consequence of functional hypertrophy. Strength development does not just result from increased motor unit recruitment and firing rate. However, ideally we need to limit proteolysis so muscle recovers before track.

Is protealysis a precondition or a side-effect?

Anyone care to answer?