Hypertrophy Specific Training: Targeted HST Workouts to Spark Muscle Growth

HST, or Hypertrophy-Specific Training is a practical way to look at the scientific research and physiological principles behind muscle growth. By combing through the research and science, a workout model is developed that applies to the real world and falls in line with many "old school" principles, while differing with them as well in some key areas.

Basically, in an attempt to understand the exact mechanisms of muscular hypertrophy by looking at the research at a cellular level, many observances were made and certain "truths" were formed about designing a workout program that focuses purely on building muscle.

Here are the main principles & truths that have been discovered:

1) Sufficient Load
The most obvious factor in muscle growth is that some degree of mechanical load(weight) is needed to generate muscle tension, which in turn influences many growth factors related to hypertrophy. Generally speaking, loads need to be in excess of 60% 1RM(1-rep maximum), although there are a few exceptions to this.

2) Frequency of Stimuli
Each time you train, a new "anabolic environment" is created to promote the growth of muscle, returning to normal in about 36 hours. This means that beyond the 36-48 hour timeframe, your muscles are ready to be trained again to create a new "environment". In this sense, peak recovery lasts at most 2 days, and beyond that the muscles are basically returning back to normal. Since research shows that this "normalizing" process can occur even if a muscle is trained again in 48 hours, the practical conclusion is that loading a muscle group every other day may be optimal for building muscle (as long as volume per workout is relatively low).

3) Progression of Load
Muscle tissue adapts to a mechanical load rather quickly by becoming resistant to the load's damaging effects. Once a tissue becomes resistant to a given load, hypertrophy will stop. This effect can happen in as little as 48 hours after loading. Therefore, in order to continue the growth cycle, mechanical load needs to be increased in a controlled manner over time.

4) Strategic Deconditioning
There are certain limitations to increasing the load over time, because a strength plateau is inevitably reached and it may not be feasible to continue lifting heavier. At that point, a systematic deconditioning of the muscle is needed to make it more responsive to mechanical loading. By strategically deconditioning the muscle, you can prolong the hypertrophy cycle without having to chronically lift heavier and heavier (although strength should be increasing over time).

5) Training in Higher Reps For a Period of Time
By training in the 15+ repetition range, lactic acid accumulation is increased which has been shown to enhance healing of tendons and prepare the muscles and tendons for the heavier loads that are about to follow. In addition, even the higher rep ranges have been shown to stimulate muscle growth in several studies, allowing for a more sustainable hypertrophy cycle.

6) Compound Movements
Since the overall volume is low and the frequency is high, compound exercises are utilized to place stress on as many muscle groups as possible within a workout. Compound exercises, although quite taxing, are simply more efficient by getting more work done in less time.

7) Low Volume Per Workout
In order to train a muscle group more frequently, volume is kept to about 1-2 sets per workout. There is some evidence that a single high intensity set can yield about the same benefit as multiple sets, even in trained individuals. Over the course of a week, relative volume per muscle group, due to the frequent training, comes out to be average. With low volume per workout, CNS fatigue is controlled and the ability to create a new anabolic environment every 2-3 days is optimized.

8) Eccentric Workouts
One of the most well-researched subjects in exercise physiology is the effect of eccentric loading on muscle tissue. Increases in strength and hypertrophy are clearly attributed to eccentric loading, also known as "negative" training. An eccentric set is performed with a weight that is in excess of the 5-rep max for that exercise. This cycle extends for 2 weeks in order to prolong the greater hypertophy cycle before the strategic deconditioning phase is undertaken.