Try Some Real Type II Fun

We talk a lot about muscle here, for all the usual reasons: It’s your strength, power, and metabolic engine. It’s good for your brain and your bones. We could write entire books on our ode to muscle. But muscle is not a monolith. It’s complex tissue that comprises various fiber types that perform special jobs from running along your favorite trail to hammering in some nails. For 40+ women, we want to give some extra attention to those nail hammering ones, because they’re the ones we stand to lose most.

On a very simplistic level, we’ve got two types of muscle fiber: slow twitch (aka type I) and fast twitch (aka type II). Type I are great for endurance. They don’t produce a lot of power, but they’re resistant to fatigue and can contact over and over (and over) for a long time. Type II muscle fibers are responsible for fast movements and power. They’re great for short bursts of force, but fatigue faster. 

As we age, we lose muscle, especially the fast-twitch fibers that help us move quickly and powerfully. The menopause transition doesn’t do us any favors here as research suggests that type II muscle fibers may be more vulnerable to hormonal decline than type I fibers. 

Maintaining our power is important–especially with age. So, this week, let’s take a look at how to hang onto those fast-twitch fibers with some real “type II fun.”

Lift Some Heavy Weights

Any resistance exercise will train both type I and II fibers, but heavier loads at lower repetitions really stimulate those type II fibers into action. That’s because the heavier weight requires more force production, which triggers the recruitment of more motor units, including type II fibers. Heavy lifting doesn’t have to be all you do. But for maintaining that strength and setting the foundation for power, it should be part of the plan. (You can check out our free guide to Lifting Heavy Sh*t here if you’re looking for a way to get started.)

Get Explosive 

High intensity resistance training and plyometrics will also tap into those type II fibers. Power training, which involves moves that generate high power output–think explosive jumps, throws, and lifts–can be effective for stimulating the growth of and preserving our type II fibers. 

What does that look like? You can get started with bodyweight plyometrics, like squat jumps. You can also try boosting the velocity of your favorite lifts like squats, deadlifts, and chest presses (note: start with a lower weight, about 50% of what you’d use for heavy lifting, and add weight as you get comfortable. The load should ultimately be challenging but manageable). Adding some explosive speed does not mean sacrificing form. Only move as quickly as you can while maintaining proper form. Kettlebell swings are also an excellent way to improve power. 

And don’t neglect your upper body. Medicine ball slams, higher velocity chest presses, and some plyometric push-ups can help you maintain power through your torso, too. 

Sprint!

Short bursts of maximum effort whether you’re running, cycling, or rowing recruit type II fibers due to their rapid force demands. (This is one of those literal use it or lose it situations.) It doesn’t take much–just a couple times a week–to reap the benefits here. If you’re leery of sprinting around a track or on a treadmill, an exercise bike is an easy way to sprint safely. Or head to a hill: hill sprints generally involve shorter strides and slower speeds, so you have less impact on your joints, especially the knees and ankles.

Support Those Strong Muscles

As you’ve most likely heard by now, aging muscles become less responsive to amino acids—a phenomenon called “anabolic resistance”—and the menopause transition doesn’t make matters any better, but higher protein intake can help overcome this. The International Society of Sports Nutrition Position Stand: Nutritional Concerns of the Female Athlete recommends 1.4 to 2.2 grams of protein per kilogram of body weight per day for women of all stages, evenly distributed every three to four hours across the day. 

This is also another case for creatine. By helping generate ATP (the energy currency of our cells), creatine enhances strength and power output, which directly supports type II fiber preservation and recruitment. The general dose for muscle benefits is 3 to 5 grams a day.