What it is
The long run is the single longest run of your week — typically 90 minutes to two and a half hours, and usually somewhere between 20% and 30% of your total weekly volume. It's run at an easy-to-moderate effort throughout, not as a workout.
If you only had time for one quality decision a week, making the long run genuinely long and genuinely controlled would be it. Nearly every distance training plan ever written is built around this session.
Why it works
The long run does several things at once, and none of them can be rushed.
It expands how much glycogen your muscles can store, and — more importantly — teaches your body to burn a higher proportion of fat at any given effort. Fat is effectively unlimited; stored carbohydrate is not. A runner who fuels more of their effort from fat arrives at mile 20 with something left.
It also builds the parts of you that adapt slowly. Tendons, ligaments, and bone remodel over months rather than weeks, and they respond to accumulated repetition. Ninety continuous minutes gives them a stimulus that three thirty- minute runs simply don't.
And it builds the mental side, which is not a soft factor. Being comfortable with the third hour is a trainable skill, and the long run is where you train it.
How to pace it
- The talk test. Conversational for the first two thirds. It's fine if talking gets harder near the end — that's fatigue, not pace.
- Effort. Around 4–5 out of 10 for most of it.
- Heart rate. Roughly 60–75% of maximum. Expect it to drift upward late in the run at unchanged pace; that's normal and not a signal to slow down dramatically.
The most common long-run error is running it at base pace and calling it easy. Start slower than you think you should.
A sample session
90 minutes steady, with the last 15 minutes slightly quicker. Run the first 75 minutes at a relaxed conversational effort, then lift to a comfortable moderate effort for the finish — not a sprint, just a shift.
That small progression teaches you to change gear on tired legs, which is precisely the skill a race demands, without turning the session into a workout you'll need days to recover from.
Fueling
Under 90 minutes, water is usually enough. Beyond that, take on 30–60 grams of carbohydrate per hour, and start before you feel empty — once you're depleted, you can't eat your way back mid-run.
Practice this on training runs rather than discovering on race day that a particular gel disagrees with you.
Where it fits in your week
One long run per week, on the day you have the most time and the least pressure. Keep the day before it easy or off, and treat the day after as easy or recovery.
Build distance conservatively — roughly 10% per week at most, and hold steady every third or fourth week rather than climbing indefinitely.
Common mistakes
- Running it too fast. A long run run at tempo effort is a race you didn't enter. It costs a week of quality sessions and buys nothing extra.
- Adding distance too quickly. More than about 10% a week is where the injuries live, and connective tissue is what breaks first.
- Going unfueled past 90 minutes. You'll finish the run, but you'll finish it badly, and the recovery cost is disproportionate to what you gained.
Track it in Kamee
Start a GPS track session and check your splits afterwards rather than during. The pattern you want is an even first half and no dramatic collapse in the last third — if the final splits fall off a cliff, the run started too fast, and the fix is in the first ten minutes, not the last thirty.