Post 21: Rep Ranges, What Do They Mean?

          Ok, so this may not be exactly groundbreaking, but I've come to a pseudo-conclusion about rep ranges and strength development. Athletes may or may not notice patterns in rep ranges throughout their training and pick up some inkling (read: slight knowledge, or suspicion) of periodization without really realizing it. However, as coaches, just as every exercise should have a purpose, so do the rep ranges that govern how much work actually gets done. My initial understanding of rep ranges was low volume for core movements, high volume for assistance movements. As I gained better knowledge about energy systems, I figured that these concrete parameters need not apply for types of exercises, but for the strength quality desired in the training effect. What I mean by this was the typical low volume for strength and power, high volume for endurance and hypertrophy model. Later in the year we started messing around with time under tension (TUT) and recording our results before failure: total reps, speed, time etc. More recently, while experimenting with some "HIT" style workouts for my summer training - I gained more understanding of what I was actually achieving using different rep ranges. Finally to tie it all together, I was referring to some notes I made in the past from some of Louie's work on the dynamic method, and I saw light!

Prilepin's Chart

          In Louie's work, there is reference to Prilepin's chart and speed of repetition execution. In as few words as possible, it says:

-At 70% 1RM, force production decreases at the 7th repetition.

-At 80% 1RM, force production decreases at the 5th repetition.

-At 90% 1RM, force production decreases at the 3rd repetition.

          Now, these are going to be somewhat ambiguous figures, depending on the athletes you're working with, and what type of training effects you have created with them in prior sessions or training blocks. BUT we're onto something.

          What I'm getting at here, is that force production, the energy system targeted, and time under tension all play an equally important role when determining rep ranges. To use the most popular and common example, it's believed that 45-60 seconds (60 being on the high-end) under tension, with anywhere 30-45 seconds rest in between (with a high intensity) is optimal for developing hypertrophy. This is due to the fact that during this event (assuming there is no break in the eccentric-concentric chain) vasoconstriction of the vessels and capillaries within the muscle causes immediate post-set influx of fresh blood and the PUMP that people so often talk about. To bring this back together, assuming a quality rep takes 3 seconds, 45-60 seconds under tension lands us in the ballpark of 15+ reps, classic hypertrophy prescription! 

          Also, notice the quality of work done, according to the above parameters from Louie and Prilepin. You'll notice that when dealing with high intensities (85% and above) as we all have, that your speed of rep execution decreased a LONG time before you got to that 15th rep (including forced reps.) That's because this duration of exercise slaughters ATP-PC stores, and gets into lactate onset. Consequently, hypertrophy and endurance are two qualities attributed to the classic 12-15 rep range.

          In regard to this, I'm not so sure we've had it right all along using concrete numbers to determine training effects and stimulus, but we're on the right track. What many people overlook or tend to disregard is the cause of these training effects, and even then, this requires coherent execution by the athletes we train. I think rather, speed of execution, and time under tension are more relevant factors when training. To illustrate this, think of strength-speed training. Typically, 1-3 reps are used at 90%+ (again: see above parameters) to maintain speed of execution. While I agree that this is certainly a safe guideline for strength-speed, there's not a doubt in my mind that certain athletes with different muscle fiber compositions could possibly achieve a 4th or 5th rep without diminishing returns.

          Having said that, training optimally on an individual basis becomes a very tedious task, but it can be done. Using "tendo unit spotters" in particular when developing strength-speed, could ensure that athletes are completing the optimal number of repetitions based on their personal characteristics and thereby enhancing the quality of training effects that are created. This is additionally productive in ensuring that we get what we can out of individual athletes on any given day. In this scenario, a specified percentage, and speed of execution become the parameters for a given set, and rest intervals could be determined by heart rate recovery.

-Alex