A forum post on Strengthcoach.com regarding the Tempo Method of training as outlined by Joel Jamieson led to some discussion regarding the speed of muscle action. The proposed outcome of the Tempo method is hypertrophy of the oxidative muscle fibers with the goal of increasing their capacity for aerobic energy production, which in turn improves anaerobic endurance due to their role in converting lactate back to ATP. The tempo method as described by Jamieson has the following parameters:

2 Second Eccentric/2 second Concentric with no rest between sets (2-0-2-0 Tempo)
3-5 sets of 8-10 reps per exercise
This results in a 32-40 second set length with an equal amount of time under tension, and a total time under tension per exercise of 96-200 seconds

It has been established that moving a resistance slowly intentionally trains slow movement, while the intention of moving a resistance quickly facilitates the development of faster movement. Because of this, the 2 second concentric may be seen as problematic for athletes where speed is a critical component of successful performance. I would like to propose an alternative, but before focusing on potential problems, let’s examine the theory behind Tempo Training.

The hypertrophic effect of strength exercises is related to the influence of both Mechanical and Metabolic stimuli, with mechanical Stimuli associated with higher training loads and Metabolic Stimuli associated with lactate accumulation in the muscles. We know that limiting blood supply through the use of occlusive cuffs can stimulate the metabolic effects at lower load than normally used, but can be inconvenient.

Isometrics can also be used to generate tension under conditions of reduced blood flow, but with poor transfer to dynamic strength. In the article below reprinted in Human Physiology and provided by Patrick Ward, the authors tested a “hybrid method of strength training, based on the absence of relaxation of the working muscles in the final phase of the training movement” which they termed the Low Intensity Method of Strength Training without Relaxation (LIMWR). They conducted three experiments contrasting traditional strength training with loads of 80-90%1RM and complete rest between sets, with LIMWR methods, which had higher volume at 50-60% 1RM and only a 30 second rest periods between sets. Additionally, The LIMWR repetitions were performed at constant speed, 3.5x slower than the higher-intensity group. The ROM was shortened in the LIMWR groups by about 15% total without a pause at the top or bottom, thus the ratio of muscle tension to relaxation was 100% to 0%. In the LIMWR groups the cross-sectional area of Type I oxidative muscle fibers increased by an average of 17-18%, compared to 5-8% for the higher-intensity groups (the area of Type II glycolytic fibers increased by 5-9% compared with 23-33% in the traditional groups). Based on this, it appears that the metabolic effects of constant tension can be used in lieu of external occlusion to emphasize hypertrophy of the Type I muscle fibers. The authors conclude in the article that it is the non-relaxation method, where the Work:Rest ratio within a set is 100% to 0%, rather than the speed of the muscular contraction itself, responsible for the effects. That said, there are a few caveats:

Volume used in the experiments as a measure of Time Under Tension was much higher than as outlined by Jamieson:
- 96-200 seconds per exercise (300-800 per session) for the Tempo Method as described by Jamieson
- 600-1000 seconds per exercise/session for the first LIMWR groups. The higher numbers were used to equalize volume between the experimental and control groups
The speed in the experiments WAS slower with the LIMWR method and there is no experiment comparing two Low-Intensity non-relaxation methods with different contraction speeds, so we don’t know for sure if the authors’ implication that the reduced blood flow was the key difference in the hypertrophy of the Type I fibers, or if it had something to do with the speed of contraction
Isotonic exercise such as a bench press or squat with a barbell when performed at higher velocity imparts momentum as well as changes in muscle tension based on joint angles throughout each repetition, and these changes in tension could result in increased blood flow, counteracting the intended effect. This effect is mitigated by using a slow concentric contraction as proposed by Jamieson, however the problem with the intentionally slow concentric is, well, an intentionally slow concentric.

I propose the use of accommodating resistance such as bands or chains to obtain the benefits of the constant tension without the intentionally slow concentric. The parameters would be as follows:

Once the set begins, there is lockout or pause, until the set ends. This is important, because the average repetition is typically perceived to have very little pause, but in practice there is enough rest to allow for an increase blood flow. Reducing the ROM by 10-15% as in the experiment seems to be a good way of mitigating this.
The total time of the set should be approximately 40 seconds, with a range of 35-50 seconds
The number of repetitions should be about 8-12, but this is less important than making sure that the length of the set is between 35 and 50 seconds
The fixed weight (barbell plates) should be at least 30-40% of 1RM. Nuclear MR Spectroscopy has shown metabolic changes in working muscle with 30-40% 1RM with restricted blood flow similar to changes with traditional strength training. 20% 1RM was found to be too low.
The accommodating resistance would then be added based on the speed and rhythm of repetitions. The athlete should be trying to accelerate the bar as quickly as possible during the concentric, but no momentum should be developed, and in fact the increasing resistance should help facilitate the slowing of the bar towards the top, helping to limit the ROM.
The Eccentric phase should be as long or longer than the concentric
Total number of sets is 3-4
Rest period between sets should be 30 seconds
Total number of exercises using this method per day is two and per week is no more than four
Limit consecutive weeks using this technique to three
Remember, no pausing or rest during the set, as this will result in a loss of muscle tension, allowing an increase in blood flow.

This method is a taxing technique due to both the maximal acceleration effort as well as the high concentrations of H+ that will occur. Additionally, it’s a departure from more traditional methods that will be more effective for the development of strength and hypertrophy. Therefore trials of this method should be reserved primarily for experienced lifters. That said, as a component of certain training blocks it should prove an effective way to increase the size of the oxidative muscle fibers, improve lactate utilization and thus stave off fatigue of the glycolytic fibers, without introducing external compression or using purposefully slow concentric muscle actions.

Modifying the Tempo Method, Or, Occulsion Training without a Tourniquet