What he says is technically accurate, but flawed. He’s focusing too narrowly on one particular aspect of weight training and drawing erroneous conclusions because of this excessive focus, in my opinion.
He’s saying that you need to have greater perceived effort on the last few reps. The problem is that to fatigue slow twitch fibers, you have to work for a longer time. But if you do an activity for too long, the bundles of slow twitch fibers you originally recruited may have a chance to recover and contribute strength to the effort again before you actually target any of your fast twitch fibers.
This is the reason for training with weights that fatigue you within a relatively short time. The only way to do that is to train with a load that requires the most fibers to work against it in a short time. Which is why you train with the heaviest load you can for the repetition range you’re aiming for, while maintaining good form to prevent injury. In other words, what people are doing right now. He says he’s disagreeing with standard strength training principles, but he’s not disagreeing at all if you follow the facts of his argument rather than his opinion.
One of his points is that isometric contractions result in the greatest strength gains. Yes, there is no question that isometric exercises recruit more muscle fibers, but training that way produces maximal strength at that particular joint angle. You can use the increased muscle size and associated strength across a greater range of motion, but it’s generally less useful than training at high resistance across the whole range of motion in the first place.
For an even more extreme approach, a Japanese research team tried moderate resistance training coupled with blood restriction and found that it does result in strength gains. The problem is, this principle could obviously only be used for training limbs, not core muscles, which makes it useful mainly for rehabilitation.
There are differences in muscle adaptation to dynamic vs. isometric training. If you need to move fast, you want to train dynamically. If you want to generate power quickly, you need to train dynamically. Isometric training will allow you to generate higher peak force, but that’s not the whole story, and it’s not optimal for many sports or activities. It’s also a bit contradictory to his point in that isometric training is trying to generate force against an immovable object. If he honestly believed that was the best way to train, there’s no reason to ever do any resistance training with a weight you can actually move, which is the exact opposite of what he concludes.
Yes, training with lighter weights over a longer rep range will result in strength gains over time, but only if you steadily increase the weight to match the resistance to the strength production. Whoops, there we go, we’re lifting heavy weights again.
In addition, at some point you need to cycle to a different load or rep range to prevent overly-specific adaptations to that particular stimulus. If you do nothing but moderate weights for a certain amount of repetitions, you get good at doing that number of repetitions at that load. But if higher demands in the strength or time domains are required, you won’t be capable of performing well, or in some cases at all.
There are also neuromuscular adaptations that he’s ignoring. It is documented that selective recruitment of different muscle groups takes place under different training regimens and that inhibition of antagonist muscle groups produces changes in performance. Particularly for beginners, the main strength increases from weight training are due to disinhibition in muscle recruitment and suppression of antagonist muscle contractions. In other words, the muscle was physically capable of producing more power than the person was able to ask it for before training, and other muscle contractions were getting in the way of the desired movement. The physical properties of the muscle change much more slowly than the recruitment effects.
One rep max testing, which is used in medical studies and by athletes themselves to gauge real strength gains, is basically subjecting you to a barely sub-isometric load. One reason athletes subject themselves to high weight/low rep cycles is to train their bodies and minds to deal with peak strength loads with little to no ramp-up, and to test for increased strength gains due to earlier cycles with lower weights and higher repetitions. Which again, is not at odds with his point of being able to train for greater strength at lighter loads relative to your maximal strength.
