There’s a precise moment—usually toward the end of August—when the air runners breathe changes. I don’t mean temperature (if only!), but energy. Chats fill up with words like “long run,” “taper,” “race pace.” It’s the season when we start dreaming again about big fall marathons. And, right on cue, it’s also the season when the gravest training sins show up.
Here’s the paradox: the same enthusiasm that gets you lacing up every day is the very force that can send you straight into a wall by week four.
So let’s look at the three most common—and serious—mistakes you can make at the beginning, and how to avoid them so you reach the start line healthy and prepared.
1. The Illusion of “Miles in the Bank”
You’ve got the bib, you’ve got a plan (or think you do), and you’re itching to crush it. The temptation is strong: ramp up weekly mileage like you’re playing a video game, stacking points to level up. Too bad muscles and tendons don’t think in pixels.
Jumping volume too fast is like asking an engine to go from zero to a hundred in three seconds without ever warming it up. The result isn’t glory but a dashboard full of red lights: inflammation, chronic fatigue, and weeks lost to ice packs and swear words.
The way out:
- Respect the unwritten 10% rule. The dullest—and most effective—golden rule: don’t increase total weekly mileage by more than 10% over the previous week. Period.
- Deload weeks aren’t for the weak—they’re for the smart. Every 3, at most 4 weeks, schedule a lighter week. That’s when your body doesn’t rest—it absorbs the work and grows stronger. Skipping it is rookie behavior.
- Get this in your head: running a lot is not the same as running well.
2. The Big Lie of “I Don’t Have Time, So I’ll Just Run”
The logic sounds tidy: the marathon is a running race, so to prepare you just run. Wrong. To keep the car metaphor going, it’s like building a Formula 1 engine on an economy chassis. Under real load, it falls apart.
Running without a strength base is a losing bet from the start. And no, you don’t need to be a bodybuilder. But you do need solid foundations to handle the stress of 42 kilometers.
The way out:
- Get marathon insurance. Commit at least two sessions a week of 20–30 minutes to strength work. Consider them the most valuable minutes of your prep.
- Be functional. Skip the fancy machines. Focus on squats, lunges, planks, glute bridges, and core stability. Moves that mirror running and make it more efficient.
- Be strategic. Slot these sessions after an easy run or on active rest days. They won’t steal energy—they’ll give it back.
3. Turning the Sunday Long Run Into a Race Against Yourself
The long run is the temple of marathon prep. It builds physical endurance, teaches your body to burn fat, and—most of all—trains your mind to stay on your feet for hours.
The most common mistake is profaning that temple—turning it into a disguised race to soothe your ego. Running longs too fast won’t make you faster. It just trashes your legs for the next few days, raises injury risk, and keeps you from learning crucial lessons: how to drink, how to fuel, how to manage the dip.
The way out:
- Learn the math of going slow. Your long-run pace should be 45 seconds to 1 minute per kilometer slower than your target marathon pace.
- If it feels too slow, you’re doing it right. Comfort on the long run signals you’re in the right aerobic zone. It’s a smart runner’s badge of honor.
- Use the long as a lab, not an exam. It’s the perfect time to test gels, hydration, gear, and mental strategies. Don’t waste it “chasing time.”
The Root Error Behind It All: Flying Blind
These three mistakes share a parent: no plan. Starting marathon prep without a program is like trying to cross the ocean in a rowboat without a compass. Romantic, maybe—doomed, definitely. A good plan isn’t a prison; it’s a map. It tells you when to push, when to ease off, and—above all—when to rest.
You Win (or Lose) the Marathon in the First 30 Days
The miles you run in month one won’t carry you over the finish line. They’ll let you reach the start line healthy, strong, and ready to enjoy the ride.
Think of your prep as a house: the foundation isn’t visible, but it’s the most important part. Start easy, build strength, respect slowness.
You’ll try race pace when it actually matters. On that day. Marathon day.