Tyler Robbins Fitness

Tyler Robbins has his B.Sc. in Biochemistry: Pre-Medical, is a Certified Strength and Conditioning Specialist (CSCS) through the National Strength and Conditioning Association (NSCA), is certified through USA Weightlifting, and a CrossFit Level 2 Trainer.

P90X3 "The Challenge" questions and discussion about hypertrophy, break periods, sets and reps

Our team struck up a conversation in our P90X3 Challenge Group the other day, I figured I would share with my blog readers.

I noticed something today in the Challenge. Taking shorter breaks causes the "pump" to arise faster and stay longer after the workout. Is that just me or am I being crazy? It took me longer to recover from the workout as well compared to X and X2 versions of Chest and Back. Usually by the end of the cool down my pump has subsided from where it was in the middle and my heart rate is back down. Not with the Challenge. I noticed it last week too but this is the only one I have noticed it with. So I was wondering if anyone else noticed their pump lingering and heart rate higher than what they would consider their normal resting heart rate? Like 20-25 minutes after.

Alright, when it comes to rest periods, anything under 30 seconds rest is considered "Endurance." 30-90 seconds rest is "hypertrophy" and so on. Since this is circuit training, you are alternating muscle groups, so while one works, the other "rests." So, technically, after a set of pull-ups, by the time you do your push-ups, take a quick rest, and then get back to the pull-ups, you have fallen right in that "hypertrophy" zone. A workout like Chest & Back ends up lengthening this time frame from "back" set to "back" set by a longer period of time. Not only that, but the repeat only happens after 12 different sets in C&B whereas in The Challenge, you repeat right away, blasting the same muscles again.

As for the heightened heart rate, that is known as EPOC (excess post-exercise oxygen consumption) - scientists make acronyms for everything by the way!

Basically, your body uses 2 forms of energy production - aerobic (with oxygen) and anaerobic (without oxygen). It isn't a definitive switch from aerobic to anaerobic, but more of a combination of both at any given time. As long as your body is able to keep up with energy demands by breathing fast enough, then you will stay in aerobic (walking, light jogging, etc.). As soon as you really start to push the pace, your heart rate and breathing will increase in pace, but you will eventually reach a point when your heart rate and breathing can't keep up.

*NOTE* - One exception to this rule. When you have to generate a lot of force or power (i.e. lifting a very heavy weight), your body uses anaerobic metabolism.

For a routine like The Challenge, your body just can't keep up with the demands of cranking out reps with such little break, so you end up with a backlog of oxygen demand. Think of it as an assembly line in a factory. As you get backlogged, you start writing "I-O-U's." So, when the workout is over, your breathing and heart rate stay elevated to pay back all of those I-O-U's. The more you push yourself, the more I-O-U's you have to pay back.

Is it fair to say that this (The Challenge) is a better hypertrophy workout than Chest and Back because of the way you blast your upper body? Also, could I use the information of I-O-U's to determine how hard I push myself? The longer it takes for my heart rate to recover the harder I pushed myself kind of way?

Yes, I would say it is better than Chest & Back for creating a "pump" because your breaks are shorter, although both are probably pretty equivalent in the "hypertrophy" department. The optimal rep range for hypertrophy is 6-12, so by cranking out pushups and pull-ups, you are actually working your muscular endurance more. As for the IOU's, the more you do a specific routine, your body will get better at recovering faster than before. This is your body's way of adjusting to the demands.

So if my reps turn out to be less than what they're all doing, I could achieve the same thing by fast forwarding to the next move if I finish early?

Let's elaborate a bit. Your muscles are all made up of 2 different types of fibers, type 1 and type 2. Type 1 are Aerobic, have good "lasting" properties (can work for long periods of time) although don't generate much force.

Type 2 fibers are MORE anaerobic, can generate greater forces, although aren't as good for long periods of time. With a routine like The Challenge, you are working both types of fibers. Again, both types of fibers may be "working" at any given time, but more emphasis gets placed on one type over the other at certain points depending on the work being done.

With a routine like the Challenge, although Type 2 fibers are more anaerobic in nature, you can actually transition Type 2 fibers to become more aerobic, or more "efficient." Type 2 fibers have a series of "sub-types" within. So, they can perform better at a routine like The Challenge and become better at aerobic metabolism, but will lose a bit of overall strength in the process (ability to generate large amounts of force).

So, this is where a program like Body Beast (or any hypertrophy-based program) comes into play, and what I have attempted to teach people in the past. By putting on mass, you aren't just trying to become a body builder, but increasing the size of your muscle fibers so that when you do a routine like The Challenge, you can "transition" those type 2 fibers to become more aerobic and therefore, theoretically do better than you have before - improvement!

Just to note, everyone is born with a specific ratio of Type 1 to Type 2 fibers. This NEVER changes. So, this is why some people are just naturally born as better endurance runners and some others are better at generating strength/power (i.e. football players).

Whether you are doing the "Classic" or "Mass" schedule, however, think of The Challenge as a preparation routine for further strength and size gains down the road. The Challenge is designed to get you at least competent at push-ups and pull-ups. When you enter Phase 2, you will then start doing routines like "Eccentric Upper" which is designed to increase "time under tension" and therefore elicit some hypertrophy gains.

So think of The Challenge like a University course - Muscle Building 101. You would then enter phase 2 - Muscle Building 201. If you have even a decent level of fitness, then jumping into phase 2 would be fine, however, you will maximize your benefits by following the schedule as-is.