You've been told that the hamstrings are predominantly fast-twitch fibers, so for years you've been training them accordingly: high loads, low reps, and explosive concentrics with plenty of rest. You've also been told that ankle plantarflexion during leg curls increases the activation of the hamstrings, so you've been doing them in that manner as well. And you got great results initially. The problem is that your hamstring growth has stalled. No matter how much you try to shake things up, they just don't seem to budge. You've tried doing them one leg at a time… you've tried doing them seated, lying, kneeling, and standing… you've tried doing them with your feet rotated in and your feet rotated out… nothing seems to work any more!
Well, try this: cut the weight in half, do more reps, and go slow. For example, if you typically do 4-6 sets of 4-6 reps trying to lift the weight as fast as possible, do 2-3 sets of 8-12 reps at a 4-0-2-0 tempo with half the weight. Make sure you perform the tempo correctly. You don't need to go super slow, but you do need to go slow enough to feel the muscle contract. And you don't need a metronome to do it. It should be "one-mississippi-two-mississippi" on the way up, and "one-mississippi-two-mississippi-three-mississippi-four-mississippi" on the way down. Establish the speed and range during your warm-up sets, and then it should be on automatic come your work sets.
What A Difference!
You’ll soon discover what a difference this type of training makes. Usually, you initiate a leg curl with a blast of force and momentum takes over the rest of the way. The hamstrings don’t do much after that initial pull – they just come along for the ride. Because you’re using a weight that’s probably too heavy, your form goes to hell in no time: your butt raises so far in the air to shorten the distance of movement, and no matter how good your intentions are to maintain ankle plantarflexion, by the second or third rep you're already in dorsiflexion as your gastrocs are coming into play to help out. I promise you, if you do leg curls right, even with a fairly light weight you'll really feel your hamstrings.
Now since you’re only using half the weight you normally do, you’ll be able to cut the rest in half as well. You’ll need less rest between sets and less rest between workouts. If you typically take 3-4 minutes of rest between sets, 90-120 seconds will be enough with a lighter weight. And if you normally train your hamstrings heavy once a week, you can go light twice a week.
Get Ready For A Challenge
Don’t be fooled when you commence this type of training. It’s more challenging than you may think. The first set should be manageable, but after that your performance may drop dramatically. You may lose several reps by the second set, especially if you’re not used to doing this type of training for your hamstrings. No problem, lift the load in dorsiflexion as you fatigue, but always lower the weight in plantarflexion. On the third and final set, use less weight and try to maintain plantarflexion throughout.
When you train in this manner, you can’t hide any weakness. Both your left and right hamstrings must work throughout the entire range of motion, not just part of it. You may feel that one side dominates if an imbalance has occurred over time without you knowing it. Light and slow leg curls will unveil a left-right discrepancy very quickly, believe it or not. If a muscle imbalance does exist between both sides, do the exercise one leg at a time. Of course, start with the weaker side first.
Encourage New Growth
Perform this type of training twice a week for a good 3- or 4-week period, and you'll encourage growth in fibers that have been dormant for quite a while. You may have been attacking the type IIb fibers for years, but it doesn't mean that you can't hypertrophy the type I and IIa fibers. In fact, that may be exactly what you need to encourage new growth. And keep in mind that you'll recruit a greater number of fast-twitch fibers as you fatigue, so make sure to take each set to failure to truly reap the benefits of this type of training. Really, how fast-twitch dominant are the hamstrings anyway? On average, the biceps femoris is 66% type I fibers (see Table 4 on page 30 of my book The Elite Trainer). It’s just another reason to give this method a shot.
Trust me, this method of training your hamstrings can't hurt. In fact, I guarantee that you won't get hurt using this method of training. If you do it right, you’ll feel your hamstrings work. It may be the first time in years that you truly feel them contract. And you’ll see them grow! Again, it may be the first real growth you've had in that area in years.
The weight you use may be light, but your hamstrings will feel heavy by the end of it, so don’t take this method too lightly. Once you try it, you won’t look back … that is, unless your marveling your new hamstring growth!
To your success,
John Paul Catanzaro
Posted May 1, 2017