Q: How should I be seeing progress from a given routine? For instance, should I experience visible improvements each week? How about weekly strength improvements?

A: Strength and size aren’t directly correlated; strength can occur through neuromuscular development (better nerve force) and tendon and ligament strength, and size can occur through capillary-bed enlargement and mitochondria development—that is, endurance-component density. That said, you should strive to get stronger, but it shouldn’t be your main focus, and it won’t happen at every workout—at least not after you’ve been at it for a while. Beginners can get stronger at almost every workout for the first few months. In our e-books we identify max force, stretch overload and tension/occlusion as the three primary facets of building larger muscles as quickly as possible. Cover those, and you should be fine. We design our workouts to attack each of them, with max force usually taking the lead. You can do it with full 3D POF programs if you have time. With 3D POF you train the midrange, contracted and stretch positions, using from one to three exercises per bodypart. Triceps is a great example. For midrange (max force) do close-grip bench presses; for contracted (tension/occlusion) do pushdowns; for stretch (stretch overload) do overhead extensions. If you have time constraints, use one big, or compound, exercise per bodypart in a more abbreviated workout structure— for example, Time-Bomb Training in our new e-book, X-traordinary Muscle-Building Workouts. You use the twoset/ drop method: one set to exhaustion, with X Reps, rest, then a drop set with the same weight and X Reps on the second phase of the drop. It’s very efficient, covering the three components of muscle growth to a degree, although it’s not as effective or precise as full-on 3D POF. If you lose some bodyfat and train consistently with proven guidelines, you should see spectacular improvements in a month or so, and that should motivate you to keep improving. The gains will be in the form of some strength and visible muscle. Keep your eyes on the mirror, and be aware of how your clothes are fitting. They should be getting looser at the waist and tighter in the sleeves and across the back.

Q: I’ve found much conflicting information on the Internet. Some strength coaches have a different interpretation of the size principle of muscle fiber recruitment from yours. They say that during a set, the fast-twitch fibers fire first, and once the rep speed slows, the slowtwitch fibers take over. Some say that’s a reason to not go to absolute failure—because slow-twitch fibers have little size potential. That does seem to make sense, as the rep speed always starts to slow about two thirds of the way into a set. You stated that the size principle is the inverse of that interpretation— that it’s only by going to failure that you begin to engage the fast-twitch fibers. How do you respond to that?

A: First, let’s clarify the size principle of fiber recruitment that I subscribe to. According to Steven J. Fleck, Ph.D., and William J. Kraemer, Ph.D., two of the most respected strength researchers in their book Designing Resistance Training Programs: “According to the size principle of recruitment of motor neurons, the smaller, or low-threshold, motor units are recruited first. Low-threshold motor units are composed predominantly of type I [or slow-twitch] fibers. After low-threshold motor units, progressively higher-threshold motor units are recruited based on the increaseing demands of the activity. The higher-threshold motor units are composed predominantly of type II [fast-twitch] fibers. Lifting heavier resistance will start with the recruitment of low-threshold motor units (type 1). The high-threshold motor units (type II) needed to produce greater force will be recruited as the force required increases.”

So on a bodybuilding-style set of eight to 12 reps, I believe, as Kraemer and Fleck do, that the slow-twitch fire first and the fast-twitch progressively come into play as the reps get harder, with the key fast-twitch growth fibers activating on the very hardest reps at the end. I don’t think you have to go to absolute failure, however, to recruit high-threshold motor units. You can get to a few even if you stop short. Doing more subfailure sets after that will recruit a few more because you get different recruitment patterns on each set. It’s the reason bodybuilders like Bill Pearl got big while using subfailure volume training. If the opposite were true— that the fast-twitch fibers fired first—distance runners would train mostly fast-twitch fibers, as the resistance on every step is like the first few lighter reps of a weight-training set. I admit that I’m still learning too, but that doesn’t make sense to the logical side of my brain, as muscle biopsies show that distance runners have predominantly slow-twitch fibers. I don’t totally disagree with the other interpretation, but I think it applies only to heavy strength-oriented sets, like three-to-five-rep maxes. With resistance that close to maximum, the high-threshold motor units come into play immediately. The nervous system craps out very early, however, and all that are left are the slow-twitch fibers, but they never get in on the action because of lack of anaerobic capacity. In that case the fast-twitch higher-threshold motor units do fire first, but it takes considerably more volume to get at enough fast-twitch fibers to elicit a growth response. Nerve force, a key to strength increases, is taxed considerably and improved on with low-rep training—that’s why it’s considered best for strength and not so great for building size. With bodybuilding sets of eight to 12 reps, on which the first reps are fairly easy, the low- and medium-threshold motor units fire first (probably a mix on eight-rep sets and more slow-twitch fibers on 12-rep sets, where early reps are very easy). That’s why X Reps are so effective on bodybuilding- style sets. End-of-set partials keep the size principle engaged and force more fast-twitch growth fibers to fire after full-range exhaustion.

Q: I purchased the e-books Beyond X-Reps and The Ultimate Mass Workout at your site [www .X-Rep.com], and I absolutely love them. Gains have been great, and even my trainer has been following my lead and using X Reps in his program (I told him to buy the program, but he’s a bit of a cheapskate— LOL). I love all the research you guys put into this, but I was wondering why in your X-Rep Hybrid Mega-Mass Program in Beyond X you don’t designate the X spot for each exercise. In the Ultimate Mass programs every X spot is pointed out. I’m also somewhat confused by the designations in Beyond X; for example, cable upright rows using DXO + X Reps. Can you elaborate?

A: In Beyond X, the followup to UMW, we explained that the research proves the optimal X spot to be near the start of every rep, when the target muscle is somewhat elongated, on every exercise. In our first e-book, UMW, we were linking the X spot with an exercise’s Position of Flexion, such as Xing at the top of leg extensions, the bottom of sissy squats and the middle of squats. Including the semistretched point on each X Rep, however, appears to be a better approach—Xing near the turnaround, such as the bottom of an incline press, the bottom of a leg extension and so on. Not that you can’t use X Reps in the other positions. In fact, we often use X Reps at the top of one set of leg extensions, and then we do our second set with X Reps near the optimal bottom of the stroke—where the quads are elongated. Again, notice that the ideal X spot is near the start of a rep, where the target muscle is somewhat stretched for max-force generation and fiber recruitment, but why not do it at both spots for unique stimulation? We like the variety and the results we’ve achieved doing that. As for the designations, on cable upright rows with DXO + X Reps, you do your set to exhaustion using DXO reps, which means performing an X Rep at the bottom after each full rep—like 1 1/4s, with the quarters being in the starting, semistretch turnaround spot. When you reach failure, you continue with X-Rep partials near the bottom of the stroke, where the medial delt is somewhat elongated.