Hypertrophy for Dummies

Actually, I always used to have a slight problem with the ”For Dummies”-series, since the title seemed to suggest that you’re, well, kind of stupid. But since then I’ve browsed through one or two Dummies-books, and found that they’re not all that bad. And anyway, this post isn’t really a part of the Dummies series – surprise - I just borrowed the title.

The purpose of this post is to examine the concept of hypertrophy a little closer; how it really works and ways we can change our approach to hypertrophy depending on the results we want. I’ll try not to get too deep into the lab coat stuff, and instead keep things simple and practical.

When a muscle is subjected to the kind of stress created by resistance training, it adapts by growing. This growth is called hypertrophy. There are actually two types of hypertrophy; sarcoplasmic hypertrophy and myofibrillar hypertrophy. Now, sarcoplasmic hypertrophy is what happens when your muscles become bigger, but without a corresponding increase in muscular strength – the density of the muscle tissue is actually decreased. This kind of hypertrophy is common in the field of bodybuilding, where the primary focus is to elicit an increase in muscle size. Myofibrillar hypertrophy is what happens when the density of a muscle is increased, which leads to greater strength gains - but doesn’t increase the size of the muscle to the extent that sarcoplasmic hypertrophy does.

In reality, pure myofibrillar or sarcoplasmic hypertrophy never occurs exclusively – instead, muscle growth is always a mix between these two types of hypertrophy. But we can – by the way we choose to train – tip the scale in favor of one or the other.

So, which one is better? Well, that depends on your goals!

From a sports perspective, athletes that need to be strong and able to move fast should focus on developing myofibrillar hypertrophy while keeping sarcoplasmic hypertrophy to a minimum – since they’re not interested in carrying around excess body mass that only would slow them down. Also, a higher degree of sarcoplasmic hypertrophy means that the body’s ability to transport oxygen to the muscles become decreased, making your muscles tire faster. As a contrast, other athletes may need to be both heavy and strong to be as effective as possible – for example, a lineback in American football.

The choice is really up to you. If you’re mainly interested in performance, you want to focus on eliciting myofibrillar hypertrophy. If you’re mainly interested carrying around as much muscle mass as possible, sarcoplasmic hypertrophy is the way to go. Regardless of which kind of hypertrophy you want, there are some central aspects that you need to understand. Namely:

Number of reps
First, understand that different rep ranges creates different muscular adaptations. For sarcoplasmic hypertrophy, it’s been estimated that you should keep the number of repetitions between 8-12, at 60-80% of you 1 repetition max. For myofibrillar hypertrophy, do between 1-5 repetitions at 80-100% of your 1 repetition max.

Time under tension
Time under tension means the time it takes to perform a repetition of a specific exercise. As a rule of thumb, the speed of execution for sarcoplasmic hypertrophy is slower than for myofibrillar hypertrophy – about 5-10 seconds per repetition compared to about 2-3 seconds per repetition.

Rest between sets
Completely opposite to the logic that applies for time under tension, rest between sets needs to be shorter for sarcoplasmic hypertrophy, about 1-3 minutes. For myofibrillar hypertrophy, recommended resting periods are normally from 3-6 minutes. The reason for this is the usage of heavier weights – weights closer to your 1 repetition max – when focusing on myofibrillar hypertrophy, which stresses your nervous system more, thereby creating a need for longer rest between sets.

But wait! Isn’t it bad, immoral or even illegal to train for looks? Well, some people would like you to believe that, but there’s really nothing wrong with focusing on building a good looking physique. A goal doesn’t have to be strictly performance related to be worthwhile. It’s another matter completely that most professional bodybuilders of today are chemically enhanced freaks.

As I’ve explained above, bodybuilding type training focuses on building big muscles in a way that by some are considered to be non-functional. Of course, if you aim mainly for power and speed, this is an important consideration. However - most people that aren’t professional athletes don’t have strictly performance related goals, and while I believe that it’s a good thing to focus parts of your training on performance, I also think that there’s nothing wrong with training for aesthetics. Don’t subscribe to anyone else’s rules – make your own, based on what makes sense to you.

Related posts:

May 6, 2009 | Filed Under Training 

Comments

Leave a Reply