WED: “Behind the Whiteboard” – MUSCLE Class

We are going to launch a new series on the site called Under the Whiteboard where we dive into the physiological reasoning for the training here. Today kick starts that with a look into MUSCLE class.

Two years ago, if you would have told me that people would be kicking down the doors to MUSCLE class, I would have laughed you out of the room. Aside from Tuesday evening, we’d struggle to get 12 people in a room for that class, and it tanked in all slots where we tried to grow it.

The paradigm shift in fitness goals, combined with Coach Mark delivering the goods, and well, here we are with it as our most popular specialty class.

Today, I wanted to take some time to create education around MUSCLE class, as it’s very important to know why the class benefits you, what is behind the programming, and how you can best utilize it to your advantage.


Above all, understand that MUSCLE class is intended to grow muscle. Weird. It is worth mentioning since some assume there is direct carryover to 1R maximum strength, which there is not.

MUSCLE class achieves two primary physiological outcomes.

  1. Increase Muscle Cross-Sectional Area — The working muscles get bigger in diameter.
  2. Increase Storage Capacity for Energy — The working muscles are able to store more glycogen and ATP-PCr. We use ATP-PCr for low rep strength and power (think Tier 1 All Level in PSC), and we use glycogen to fuel intense workouts (think Tier 2). If we have more muscle, we have more of these phosphates available to fuel work, we can go harder, and we can create more favorable adaptation through training.

In addition, MUSCLE class achieves two secondary outcomes.

  1. Increase Fast Twitch Muscle Fibers — There are two kinds of hypertrophy training. Bodybuilding Hypertrophy, which focuses on isolation movements with very high rep counts often to exhaustion, and Athletic Hypertrophy, which focuses on barbell lifts at lower rep counts (6-8) and not to exhaustion. The net result of adding more muscle in an Athletic Hypertrophy setting has some proven transfer to strength in that it creates more favorable adaptations for our fast twitch fibers, which are those fibers largely responsible for strength and force production. That transfer to strength does not occur to a 1R setting, however. It is more likely that you see improvement in your 3-5R strength than your 1R. I’m not saying you won’t PR your 1R, but it’s not likely.
  2. Tendon and Ligament Strengthening — The continued strengthening of connective tissue provides a stronger base of support and athletic performance. Lower rep strength training (1-5) does not achieve the same training benefit, which is why injuries can occur in athletes who only focus on low rep, all the time. For this reason, MUSCLE class emphasizes “prehabilitation” quite effectively.

The main takeaway is that you should not go into MUSCLE class with the assumption that it’s a strength cycle, or that it is designed to increase your 1R max. However you slice it, strength is a secondary byproduct of this class, it is not the primary effect.

To think of MUSCLE as a strength-focused class would be to think that training the mile will increase your 40 yard dash. Two completely different energy systems.

MUSCLE class is lactic and fueled primarily by glycogen. Maximum strength is alactic and fueled primarily by ATP-PCr.


The combination of movements, reps, and time under tension produces muscle growth through the following mechanisms.

  1. Movements – You will notice that there is often a bigger, compound movement that loads the spine as the main class movement. Compound movements work more muscles, thus tax the body more and create a larger protein deficit (where our muscle breaks down with the opportunity to grow).
  2. Reps – As mentioned, the barbell lifts are typically programmed in an Athletic Hypertrophy rep count (6-8) where the isolation movements are typically programmed in a Bodybuilding Hypertrophy (10+) rep count. Both result in growth outcomes.
  3. Loads – Where strength is typically built in 80%+ range, hypertrophy is achieved with lighter loads of 60-80% taken to higher reps and performed more deliberately.
  4. Tempo – There is often a lot of prescribed time under tension with assigned tempo during the lifting (concentric) and lowering (eccentric) phase of the movement. This time under tension creates more stress and demand on the muscle, which leads to greater adaptation. We remove the usage of speed and momentum and like a magnifying glass under the sun, apply concentrated stress to that we are trying to work.


Simply showing up and lifting is no guarantee of results with MUSCLE. Here are a few important things to understand.

Commit (and De-Commit)
Muscle typically takes 4-6 weeks to adapt and grow. While you will feel a short term metabolic pump following a class, it is not lasting. If you attend MUSCLE, make a commitment to spend 4-6 weeks at a time focusing on it, and be consistent. When those 4-6 weeks are up, back off to allow adaptation to take place and focus elsewhere for another 2-4 weeks.

If you never back off of hypertrophy training, over time, you will put wear and tear on the contractile proteins of the muscle and you will fry their anabolic ability.

Think of MUSCLE as a step forward, then wait.

If you are not eating a caloric surplus, you will have a hard time growing. Further, if you are not eating the right kinds of food, you may be giving your engine the wrong fuel. Ensure that you are eating enough calories, and ensure that you are eating a high carbohydrate diet in the two hours pre and post workout, with little fats and high protein in that window, as well. Fats can slow the absorption rate of other macronutrients the muscle desperately needs in that window.

Because so much of MUSCLE class produces a lactic training effect, aka, the high reps produce lactate and lactic acid, glycogen is the primary fuel source. This is in contrast to strength training which produces no lactic training effect, and relies on ATP-PCr as the primary fuel. We get glycogen from eating carbs, which is why if you attend MUSCLE class, you need lots of them.

For a starting point on caloric consumption, you can check out Lenny’s article on the 5 Levels of Nutrition.

A workout is only as productive as your ability to recover afterwards. Hitting MUSCLE class hard on Tuesday and then hitting a PSC hard on Wednesday is not a winning strategy. Hypertrophic demands on the body are great, and you should be allowing yourself a day of recovery after attending a hard fought MUSCLE class.

It takes 24-48 hours to replenish glycogen stores in the average person, so unless you are eating and recovering like a professional athlete, you likely fall into that window. If you train hard without replenishing muscle glycogen, you will tap into liver glycogen. Those are the reserves. That would be like sending the National Guard to war over full-time soldiers. When those are out, we are now training on empty and setting ourselves up for an overreaching scenario. Too much overreaching leads to Overtraining Syndrome.

Additionally, you may want to consider some form of active recovery immediately following class. A light 10 minute jog following a high output lactic session (like MUSCLE) will remove 62 percent of training waste products from your body (Fox et al 1989). This will aid recovery and speed up your ability to train sooner.

All in all, MUSCLE class is a fine choice for any level of fitness provided you understand the benefits and implement the class in the proper fashion. The muscular adaptations from MUSCLE class result in a stronger engine that is better prepared for any fitness demand.


Wednesday, 10.10.18

First. For Strength
5 Deadlifts @75%
8/s Sprinter Crunches @ 3030 Tempo
*Complete 1 set every 5’ for 25’

Then. For Conditioning
3/s Front Rack Rev. Lunges
6 OTB Lateral Hops
20 Plate Flutter Kicks
150m Run