Why Moving Less Can Burn More

This Week’s Research Highlight

Most of the movement we do each day doesn’t happen in structured workouts.

Instead, it unfolds in countless tiny fragments — crossing the room to fetch a notebook, climbing a flight of stairs, pacing during a phone call. These moments seldom register as meaningful exercise. Your fitness tracker, if it notices them at all, logs them as noise.

But new research suggests that these scattered bursts may carry more physiological weight than we’ve assumed. Not because they’re strenuous, but rather because they’re inefficient. Each time you start moving from rest, your body scrambles to meet the sudden demand. That scramble costs energy.

In other words: when it comes to how our bodies burn fuel, moving less might actually cost more.

A new study offers a glimpse into the hidden metabolic toll of our most ordinary movements, and it may prompt us to rethink what “exercise” really means.

Designing a Study for Real-World Motion

The researchers began with a deceptively simple question: How much energy does it take to walk across a room, or climb a single flight of stairs?

To find out, they designed two carefully controlled experiments. One simulated steep stair climbing, the other level-ground walking.

In the first, participants walked on a stair treadmill (sometimes referred to as a stepmill) — a motorized belt set at a sharp incline, calibrated to mimic slow stair ascent at three distinct speeds.

In the second, they walked on a flat treadmill at a steady, moderate pace. Each walking bout lasted between 10 seconds and 4 minutes, bookended by seated rest before and after.

Before each trial, participants sat quietly for 3 minutes to establish a resting baseline. Then, they stepped onto the already-moving treadmill and walked for the assigned duration. Afterward, they returned to the chair for 7 minutes of recovery, giving researchers a window into not just what happens during brief movement, but what lingers in its wake.

Throughout each session, participants wore a portable gas analyzer that captured their breath-by-breath oxygen uptake (VO₂) — a gold-standard proxy for energy expenditure.

But the researchers weren’t just asking how much oxygen was used. They wanted to know when it was used, and why.

Capturing the Real Cost of Stop-and-Go Movement

When you begin to move, your body doesn’t glide into action — it lurches. Like an old engine on a cold morning, it sputters, runs rich, and only gradually finds its rhythm.

This brief lag is known as the VO₂ on-transient: the delay between when muscles begin demanding oxygen and when oxygen delivery catches up. In this phase, the body draws on anaerobic systems and internal energy reserves to bridge the gap — an arrangement that’s energetically costly.

To complicate matters, the first few seconds of movement often trigger a surge of non-metabolic oxygen uptake — oxygen consumed not by working muscles, but by sudden shifts in blood flow and ventilation. The researchers modeled and subtracted this “phantom oxygen” to better isolate the true metabolic cost of movement.

But the story didn’t end there. After each walking bout, oxygen use remained elevated during recovery. This phenomenon — known as EPOC, or excess post-exercise oxygen consumption — is the body’s quiet housekeeping: restoring balance, refilling energy stores, clearing out waste. And in short bouts, it can make up a surprisingly large share of total energy expenditure.

By capturing both the initial ramp-up and the extended recovery, the researchers illuminated something that wearable devices and exercise calculators often miss: The metabolic reality of real-life movement — stop-and-go, irregular, and surprisingly inefficient.

Why Short Walks Burn More Than You’d Expect

The data told a counterintuitive story: the shorter the walking bout, the higher the energy cost per second.

A 30-second walk, for instance, burned 20–60% more oxygen than steady-state models would predict. The task itself was modest, but the metabolic price was disproportionately high.

And this wasn’t an anomaly. The pattern held regardless of whether participants were climbing steeply or walking level ground.

It wasn’t about effort. It was about timing.

Shorter walks burn more oxygen per second than you'd expect. In each trial, the shorter the walking bout, the higher the per-second energy cost. Compared to traditional steady-state predictions, 30- to 60-second walks consumed 20–60% more oxygen, largely due to inefficiencies in the body’s startup and recovery processes.

The Metabolic Penalty of Starting from Zero

At the onset of movement, muscles call for energy instantly, but your aerobic system lags behind. In those first moments, your body pulls from faster, less efficient sources — anaerobic pathways and stored reserves — while your internal systems hustle to adjust.

Oxygen is being consumed, but not all of it is directed toward propelling you forward. A chunk goes to what researchers call non-mechanical tasks: increasing ventilation, shifting blood flow, rebalancing ions.

And in short bouts, this messy ramp-up isn’t just a footnote. It’s the main event.

That inefficiency becomes visible in a key metric: mechanical efficiency — the ratio of energy expended to useful work performed. In longer efforts, the human body excels at this. But in the study’s short trials, efficiency dropped by as much as 50%. Energy was still being burned — just less of it was going toward actual movement.

It’s a bit like flooring the gas to reach 30 mph, then hitting the brakes. Repeatedly. Most of the fuel is spent getting up to speed, not staying there.

Importantly, this goes far beyond walking. This metabolic penalty applies to any activity with frequent starts and stops: sprint intervals, team sports, stair climbing, even unloading groceries. Every transition from rest to movement re-triggers the same costly adjustment.

Why Your Fitness Tracker Might Be Missing the Point

Most wearables operate on a simple premise: that movement is continuous, predictable, and sustained long enough for your body to reach a physiological equilibrium. This is the logic behind steady-state models, the formulas used to estimate how many calories you burn during a run, a bike ride, or a brisk walk.

But daily life doesn’t unfold in steady state.

This study revealed that short walking bouts consumed 20–60% more oxygen than steady-state models would predict. Not because the movements were harder, but because they were messier. Traditional models fail to account for the ramp-up phase at the start of movement and the recovery cost that follows. Both add energy demands that simply don’t appear when you average things out over a continuous session.

This means your calorie burn may be consistently underestimated, especially if your movement comes in frequent, fragmented doses. It also means those small, forgettable moments — walking the dog, unloading groceries, climbing stairs between meetings — might be doing more metabolic work than we’ve ever been led to believe.

The Case for Moving More — Even in Tiny Bursts

All of this inefficiency can really add up. Let’s do the math.

Oxygen use is closely tied to calorie burn — roughly 1 liter of oxygen equals about 5 calories. So when a brief walk or stair climb demands more oxygen than expected, it’s costing you more energy, even if the distance or pace doesn’t change.

Take, for example, a 150-pound person who walks six times a day for five minutes at a time. Under steady-state assumptions, that might burn around 150 calories total. But if those walks are chopped into smaller, frequent chunks, the total energy cost could rise to 180–240 calories. That’s an additional 30–90 calories just from the repeated startup demands.

Add in a few short stair climbs, and your daily burn might increase by 50 to 150 calories. And this is without changing what you're doing, just how it's distributed.

Over a week, that’s 350 to 1,000+ extra calories — earned not through workouts, but everyday inefficiency.

But the benefits extend beyond energy expenditure. Brief, frequent movements can also reshape how the body handles glucose, which is why researchers have been investigating "exercise snacks" as a tool for metabolic health.

In one study, participants either sat for 3.5 hours watching television, or interrupted that time with 3-minute bouts of light bodyweight movements during commercial breaks. The result? Plasma glucose dropped by 33%, and insulin levels fell by 41% in the “exercise snack” condition.

Taken together, they paint a simple picture: The more often you move, the more metabolically active your day becomes.

The graphs show average concentrations and total glucose/insulin exposure over time (iAUC), adjusted for age, sex, BMI, and condition order. Compared to prolonged sitting, brief bouts of light exercise during commercial breaks lowered plasma glucose by 33% and insulin by 41%. A small change in routine produced a surprisingly large metabolic benefit.

Moving with Inefficiency in Mind

The takeaway here isn’t to move harder, or longer, it’s to move more often. Not in big blocks, but in brief, habitual interruptions.

Here are a few ways to engineer that inefficiency into your day:

• Break a 15-minute walk into three 5-minute bursts. Same distance, bigger metabolic cost.

• Climb stairs in shorter stints. Every trip triggers its own startup tax.

• Pair movement with routines. Stretch while the microwave runs, pace during calls.

• Batch tasks into bursts. Unload groceries in rounds, split up laundry trips.

These moments don’t need to feel like workouts. In fact, they shouldn’t. The value lies in their frequency, their fragmentation, their refusal to become efficient.

How to Make it a Habit

Try structuring your movement the way your metabolism already prefers it: opportunistically. That’s the philosophy behind our InTUNE training program — short for Integrative and Opportunistic Training.

Each day, you get a simple bodyweight workout with a total rep goal per exercise.

You can chip away at it however you like — ten reps here, twenty there—whenever you find a spare moment. The only rule? Finish by day’s end.

Over time, it shifts how you see your day. Movement stops being something you schedule. It becomes something you spot.

Summary: To explore how much energy everyday movement really costs, researchers measured oxygen use in participants walking short bouts — lasting 10 seconds to 4 minutes — on a stair treadmill or flat treadmill. Each session was bracketed by seated rest to capture both the startup and recovery phases of movement. The findings were striking: shorter walking bouts burned 20–60% more oxygen per second than steady-state models predicted. This elevated cost stemmed from the body’s inefficiencies during transitions—drawing on anaerobic reserves, adjusting circulation, and lingering in recovery. In effect, real-world stop-and-go activity proved far more metabolically demanding than it looks on paper.

Random Trivia & Weird News

🧛‍♂️ The Dracula ant holds the record for the fastest movement in the animal kingdom.

Researchers found that this ant can snap its mandibles shut at over 200 mph in just 0.000015 seconds. That’s about 5,000 times faster than a blink.

But speed isn’t its only claim to infamy.

Ironically, those super speedy jaws do not enable the Dracula ant to break down solid food. Instead, adult workers rely on a grisly workaround: they pierce their own larvae and drink their hemolymph (insect blood). Hence the name.

It’s a bizarre, highly efficient adaptation that keeps the colony alive… though it reads like an insect horror story.

Podcasts We Loved This Week

• Siim Land & Nic Verhoeven: The best supplements for longevity — roundtable discussion. Via Reason & Wellbeing.

• Wes Marshall: The lack of science in road design is deadly. Via Science Friday.

Products We Like

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humanOS Catalog Feature of the Week

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Wishing you the best,