🏋🏻‍♀️ Beat Fatigue, Keep Your Speed

If you’re noticing your sprint feels flatter, your hills feel grindier, or your lifts don’t pop like they used to—you’re not imagining it. Power (how quickly you can produce force) tends to slip in midlife and menopause. In fact, this can be the first performance hit many women (🙋🏻‍♀️ myself included) notice.

It’s easy to shrug and think, “I’m just getting older.” But what does that really mean? And more importantly, what can we do about it? 

Muscle power does decline with age—but the why has been less clear. For years, one theory was that we become more sensitive to the fatiguing by-products of exercise. But a recent study comparing young and older women and men shows that’s not the case. 

Here's what the study found: 

The “burn” chemicals—hydrogen ions and phosphate—reduce force, speed, and power in everyone the same way. Older muscles aren’t more sensitive to them.

 So what is happening? 

• Fast fibers shrink with age. These are the quick, powerful muscle fibers that let you surge up a hill or jump onto a box. Losing their size explains a lot of the power drop.

• Slow fibers stay steady. The endurance-type fibers keep their power output as we age.

• Fast fibers lose punch mostly because they get smaller. In one study, their absolute power was about one-third lower in older adults, but that was entirely explained by smaller size. Pound for pound, the older fibers were just as strong—or even stronger.

And there’s more. Some evidence indicates that older adults may fade more quickly in fast, repeated efforts—not because their muscles are more sensitive to “the burn,” but because they can build up more of those by-products during certain hard, dynamic movements. That helps explain why a set of hill sprints or bike surges can feel like they “empty the tank” quicker than they used to.

And for women, perimenopause/menopause adds another layer. Estrogen helps support muscle protein synthesis, mitochondrial function/efficiency, and repair; its decline is linked with losses in muscle quality and performance. Estrogen also influences neuromuscular signaling, which can affect coordination and explosive force. 

So, power naturally slips with age, and hormonal shifts speed up that slide unless you intervene. 

The Case for Fast-Fiber Training in Midlife

Your fast-twitch, type II, “hit it!” fibers that let you surge up a climb, bound up stairs, and explode out of the squat rack may shrink with age and the menopause transition, but they are highly trainable when you target them.

What does that look like? A lot like the advice we’ve been giving here for the past 5 years. Emphasize heavy strength/power moves, and short sprints, plus adequate protein—to counter fast-fiber atrophy—and structure work/rest to limit metabolite pile-up.

Quick-hit intervals

Short bursts: 10–30s all-out efforts (classic 30 second SIT is well-studied)
Generous recovery: Rest 2–4 times longer than you worked. For all-out repeat power, rest even longer

High velocity lifting

Lifting heavy sh*t is a great foundation for preserving type II fibers. It’s also the bedrock for building and maintaining power. Pair it with high intensity resistance training with more moderate loads and plyometric moves to stimulate the growth of and preserve your fast twitch fibers. Allow 48 hours of recovery after heavy/power days.

Strength work with added speed: When working at moderate loads (60–70% 1RM), focus on moving the bar fast on the way up to target rate of force development.

Ballistic/plyometric moves: Med-ball throws, kettlebell swings, low-impact jumps. Research shows well-programmed plyometrics can improve power and function in older adults (the study I’m referencing here was in men). Allow ~48 h after heavy/power days. 

Keep shortening velocity “alive”:

“Shortening velocity” is a science-y term for how fast your muscle fibers can contract and shorten, basically, your movement speed. Plyometrics and high velocity lifting are great for this. So, also include some work where you move fast. 

Very short sprints/strides: 8–20 seconds max, with full recovery.

Spin-ups on the bike: Ramp cadence high for 8–12 seconds, then spin easy.

Fuel to blunt fatigue chemistry:

Since midlife muscles can build up more of those ‘burn’ by-products during some repeated high-intensity efforts, fueling matters:

• Before: 20–30 g carbs 15–45 min before high-intensity work.

• During (>45–60 min): 30–60 g carbs/hour; 60 to 90 g carbs/hour for longer sessions.

• Protein: Aim for ~25–35 g at meals/snacks to support muscle repair and retention.

• Hydration with sodium and electrolytes: to keep blood flow and buffering optimal.

• Consider creatine: Creatine augments strength/lean mass gains with resistance training in older adults; effects are modest but helpful for many. Typical dose: 3–5 g/d of creatine monohydrate. 

I know some women read articles like this and think, “My God, another thing I have to do.” But power training has always been part of the recipe for aging well as an active woman. It’s baked into our advice to lift heavy, practice plyometrics, and include sprint interval training in the mix. I also like giving advice you can feel. And nothing feels more immediately satisfying than getting some of that power back–in sport and in life.