Estimated read time: 3.41 minutes (about as long as it takes to load the squat rack and then decide to just do arms instead 🤔)

Hey Performance Nerds! Jonah here. 🤓

Most of the strength benefit for runners is just lifting consistently. But the part that actually makes you faster?

Your 20-rep circuit probably isn't it. And the fix is simpler than you think.

Here's what you'll learn today:

(Augie's idea of strength training is one explosive squirrel launch. Pure power, one rep per day only.)

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💡 See this week’s full Stryd training tip at the end of this newsletter.

Running economy is the oxygen cost at a given pace. Lower that cost, and you run faster for the same effort.

Economy improves when your muscles and tendons make and return force more efficiently.

The goal of the gym isn't light, high-rep circuits chasing "muscular endurance." That's the wrong target for a runner.

Honestly, I'm not even sure you can train "muscular endurance" in a gym. And you don't need to. Every mile already builds it for you.

(A debate for another day.)

So those circuits add little on top of your mileage. Worse, they miss the strength qualities that matter most.

A meta-analysis of 31 studies from Llanos-Lagos and colleagues (2024) looked at exactly this.

The clearest economy gains came from heavy loading and plyometrics. The handful of light-load studies didn't reliably beat doing no strength work at all.

The effect was small. But it points to load, not reps.

Heavy, low-rep loading builds three qualities running barely touches:

Your foot hits the ground hard every stride. A stiffer tendon stretches less under that impact.

The tendon and calf sit in a line, like links in one chain. When the stiff tendon barely gives, the calf isn't yanked into a fast stretch-then-shorten.

So the calf stays near a held position, barely changing length. It works at a low shortening speed instead of cycling fast.

A muscle that barely moves burns less energy per stride.

The same stiff tendon also returns energy like a spring, but that's the smaller effect.

"Won't I get bulky?" At running volumes, this strength comes from your nervous system, not size. Size often stays put while your stride gets sharper.

Heavy loading and plyometrics build those qualities. A review from van Hooren and colleagues (2024) argues for pairing the two.

Lift heavy. Use about 80% of your one-rep max, and keep the reps low, around 3 to 6 per set.

Add plyometrics. Bounding, hops, and jumps train the fast, explosive force your stride needs.

Leave reps in reserve. Stop about 3 to 5 reps short of failure on your heavy lifts.

Why stop short? Grinding to failure just piles on fatigue. It adds little to the strength or economy benefit you came for.

In one trial, Zanini and colleagues (2025) had trained men add heavy strength plus plyometrics.

Late in a 90-minute run, the strength group held their economy while the running-only group faded, with fatigued time-to-exhaustion up about 35%.

That's the late-race fade you actually feel.

For most runners, consistency is the real win, especially early on. Almost any honest work helps.

Showing up is about 80% of the payoff. Heavier loads and plyos optimize the rest. You don't need to always max out.

Find your situation, follow the row.

A few heavy reps and some jumps. That's the whole ask.

Bottom line: Show up twice a week, lift with intent, and leave a little in the tank.

Welcome to the prove you’re a nerd section. Each week, I ask a question about a common running science myth.

Answer correctly, and you’ll be entered into a weekly raffle to win a package of Jonah’s favorite supplements.

Most runners group sodium bicarbonate and beta-alanine together.

That makes sense. Both can help you tolerate the burning, heavy-leg feeling during hard efforts.

But they do it in different places.

The correct answer?
A. Sodium bicarbonate increases buffering capacity in the blood, while beta-alanine increases buffering capacity inside the muscle

When you run hard, hydrogen ions build up and contribute to that burning, acidic feeling.

Sodium bicarbonate works mainly outside the muscle. It increases bicarbonate in the blood, which helps pull hydrogen ions out of the working muscle and buffer them in the bloodstream.

Beta-alanine works differently. It raises muscle carnosine over time, and carnosine helps buffer hydrogen ions inside the muscle itself.

Here’s how the votes shook out:

A. Sodium bicarbonate increases buffering capacity in the blood, while beta-alanine increases buffering capacity inside the muscle - 141
B. Sodium bicarbonate works inside the muscle, while beta-alanine works in the blood - 23
C. Sodium bicarbonate reduces lactate production, while beta-alanine increases lactate clearance - 39
D. Both improve performance through the same mechanism, but beta-alanine lasts longer - 11

Most of you nailed this one.

The main trap was Option C.

Lactate gets blamed for the burn, so it is tempting to think these supplements work by reducing lactate production or clearing lactate faster.

But lactate is not the villain here. It often rises alongside hard exercise, but the target is the acid load, not lactate itself.

What about beta-alanine lasting longer?

That is the tempting part of Option D. Beta-alanine is usually a longer build. You take it consistently for weeks to raise muscle carnosine. Sodium bicarbonate is usually more acute, taken before key hard sessions or races.

But the mechanism is still different.

Bottom line?

Sodium bicarbonate is more of an outside-the-muscle buffer. Beta-alanine builds your inside-the-muscle buffer. Same hard-effort problem, different compartment.

A few months ago I switched from a bodybuilding-style block to running-specific heavy lifting and plyos. Same easy paces since, but my stride started feeling springier.

This week's newsletter explains why. Heavy lifting and plyos build force and stiffen your tendons. A stiffer tendon stretches less when you land, so your calf barely changes length and does less work.

Stryd puts a number on that spring. Leg Spring Stiffness is how stiff your legs act as a spring when you land. Less give means less muscle work, and less energy used at the same pace.

Ground contact time may shorten too as you get stronger over a cycle. Judge it only at the same easy pace across weeks, never off one run.

Why it matters:

Starting a strength block? Set your baseline now. Pick one easy run you can repeat: same route or treadmill, same shoes, same easy pace.

Track LSS and your other form metrics in PowerCenter month over month. The trend across matched runs is the signal, not a single day.

👉 Try it on your next run