Breathe Deep: What Vermont's Hills Are Quietly Doing to Your Lungs

You've probably noticed it on those long training runs through the Green Mountains — the way your lungs work a little harder, your legs burn a little sooner, and your heart rate climbs faster than it does on flat ground. Most runners chalk it up to the hills. And sure, the hills are part of it. But there's something else going on, something happening at the cellular level that's quietly making you a better endurance athlete.

Vermont's geography is doing you a favor. And if you understand how, you can start leveraging it deliberately.

What Elevation Actually Does to Your Body

Let's start with the basics. At higher elevations, the air contains fewer oxygen molecules per breath. Your body notices this immediately. To compensate, it triggers a cascade of physiological responses — the most important being an increase in erythropoietin (EPO), a hormone that signals your body to produce more red blood cells. More red blood cells means more oxygen delivery to working muscles. More oxygen to working muscles means better endurance performance.

This is the same mechanism elite athletes chase when they head to places like Flagstaff, Arizona, or Font Romeu, France, for altitude camps. They're not just training hard — they're training in conditions that force their bodies to adapt.

Here's the thing about Vermont: while the state's peaks don't reach the 8,000-plus feet that altitude training purists prefer, the combination of consistent rolling elevation change, cool temperatures, and demanding terrain creates a training environment that mimics many of those same stressors. You're not living at 9,000 feet, but you're also not running on a pancake-flat path at sea level, either.

"Vermont runners are getting a version of altitude stimulus on almost every long run without even thinking about it," says Coach Dana Morrill, who has coached distance athletes in the Burlington area for over a decade. "When you're constantly ascending and descending, your cardiovascular system is being pushed in ways that translate directly to improved VO2 max over time."

VO2 Max — and Why It's the Number That Matters

VO2 max is the maximum rate at which your body can consume oxygen during intense exercise. It's widely considered the gold standard of aerobic fitness. The higher your VO2 max, the more efficiently your body can sustain hard efforts for longer periods of time — which is exactly what a marathon demands.

Flat-road training can improve VO2 max, but it tends to plateau faster. Elevation-varied training keeps pushing the ceiling higher because your cardiovascular system never fully settles into a comfortable rhythm. Every hill is a mini stress test. Every descent forces muscular control and reloads the legs for the next climb.

Over a full training cycle — say, 16 to 20 weeks of Vermont-based preparation — those repeated stressors add up. Runners often report noticeable improvements in their lactate threshold, their ability to sustain goal pace, and their recovery between hard efforts.

How Vermont Coaches Periodize Elevation Work

The key isn't just logging miles on hilly terrain. It's being intentional about when and how you introduce elevation stress into your training cycle.

Coach Morrill recommends thinking about elevation work in three phases:

Early Base Building (Weeks 1–6): Don't force the hills. Let them come naturally on your easy runs. The goal here is aerobic development, not suffering. Running hilly routes at a conversational pace builds your aerobic base while introducing gentle cardiovascular stress.

Strength Phase (Weeks 7–14): This is when you start incorporating dedicated hill workouts — structured repeats on grades of 4–8%, tempo runs on rolling courses, and long runs that deliberately include sustained climbs. "I have my athletes run the Stowe Recreation Path and some of the routes around Williston during this phase," Morrill notes. "Those sustained grades at tempo effort are incredibly effective for building the kind of strength that holds up in the final miles of a marathon."

Race Prep Phase (Weeks 15–20): Gradually shift toward flatter surfaces to let your legs adapt to the demands of race-day terrain. This is especially important if you're racing a flat course like many spring marathons. The elevation gains you've made are banked — now you're teaching your body to express that fitness on level ground.

The "Live High, Train Low" Concept — Vermont Style

Elite programs often use a strategy called "live high, train low," where athletes sleep at altitude to stimulate red blood cell production but train at lower elevations where they can hit faster paces. Vermont runners can approximate this in a practical way.

If you live in a hillier part of the state — think the Mad River Valley, the Northeast Kingdom, or anywhere near the spine of the Green Mountains — your daily life is providing low-level altitude stimulus even when you're not running. Your body is constantly adapting to a slightly reduced oxygen environment. Then, when you head down to the Burlington waterfront or the Champlain Valley for your speed workouts, you're able to run faster, push harder, and still benefit from the adaptation happening at home.

It's not a perfect altitude camp. But it's not nothing, either.

Making It Work Before a Flat Marathon

One of the most common questions Vermont runners ask is how to translate hill-and-elevation fitness into a fast time on a flat course. The answer involves a deliberate taper and a shift in training surface during the final three to four weeks before race day.

Here's a simple framework:

• Four weeks out: Begin reducing the percentage of hilly miles in your long runs. Aim for 60% flat, 40% rolling.
• Three weeks out: Flip that ratio. Most of your running — especially anything at goal marathon pace — should happen on flat ground.
• Two weeks out: Your legs should feel the difference. Paces that felt hard on hills will start to feel manageable on flat terrain. This is the adaptation working in your favor.
• Race week: Trust the process. You've built the engine on Vermont terrain. Now you just have to drive it.

"Runners who've done the elevation work always have more left in the tank late in a race," Morrill says. "It shows up at mile 20, 22, 24 — when everyone else is fading and they're still moving."

The Takeaway

Vermont's terrain isn't a training obstacle. It's a training tool — one that's been quietly building your aerobic capacity, strengthening your cardiovascular system, and increasing your red blood cell efficiency every time you lace up and head out the door.

You don't need to book a flight to Colorado or sleep in an altitude tent. You just need to be intentional about the hills you're already running, periodize your elevation work with purpose, and trust that what Vermont is doing to your lungs will show up on race day.

Run Vermont. Run strong. The science is on your side.