Why Strength Class? Part 3: Varying Intensity for Adaptation

In last week's post, I talked about volume and how it is implemented into a training program. Volume is important for quantifying the stimulus that a training program delivers. Not enough stimulus and little to no progress will be made. Too much and you'll find yourself in a rut and eventually regressing in your strength endeavors.

The good news is that unless you are an elite level athlete, it is pretty easy to keep training volume at a happy medium. Another aspect that must be considered in a training program is intensity. Intensity is traditionally measured by a percentage of a one rep max. These percentages can then be categorized into "zones," each of which are beneficial for specific adaptation. But... 

Why does a training program need to vary in intensity?

In short, the muscle fibers recruited to perform 3 sets of 10 back squats at 60% are different from the fibers recruited to grind out 3 singles at 95%. We can categorize training loads into four zones:

  1. High intensity (85% +)
  2. Medium intensity (70-85%)
  3. Low intensity (60-70%)
  4. Very low intensity (30-60%)

Sport scientists have accumulated an impressive body of evidence to support that each zone is uniquely beneficial, but those details are beyond the scope of this post. Instead I want to discuss why it is important to utilize ALL of these zones to achieve strength adaptation.

It is counterintuitive to think that performing reps at very low intensities can make you stronger: but it does. When performed properly, the body recruits more muscle fibers in accomplish squats at very low intensity than squats at high intensity. If you spend enough time around gyms, at some point, you'll see some massive specimen squatting 400+ pounds for reps. It may resemble a Herculean effort, but that individual can impressively get work done. Conversely, you will eventually see an unassuming guy or gal moving the same amount of weight and make it look EASY! If you spend time training at high intensities, slow twitch muscle fibers are recruited to dominate the movement, resulting in slower (seemingly more difficult) reps. If you spend more time training at low intensities, fast twitch muscle fibers will be recruited, resulting in faster (seemingly easier) reps. A good training program will provide stimulus in all training zones to ensure development and activation of ALL muscle fibers. The person squatting 400+ pounds for reps and making it look easy undoubtedly follows a training protocol that addresses all training zones.

This is why we mix it up in our Strength class. The initial point of emphasis is to develop technique (we have made some outstanding progress here). We also do a lot of tempo sets and accessory work to build muscle and speed work to ensure recruitment of as many muscle fibers as possible. Beyond that, we pick a lift to focus our training time on to gain exposure to various training loads. This methodical approach to strength development ensures a consistent return on your time invested.

We develop the Squat, Deadlift, Bench Press and Overhead Press in Strength class because they are fundamental to virtually every single movement that we do in CrossFit (yes, even running!). Strength class workouts may not be as sexy and varied as CrossFit workouts but the end result certainly is. As a coach, I am proud of the fact that every single person that has CONSISTENTLY attended Strength class has set personal records in the core lifts.

So...who's next?

-Coach Tony