7 Important Things to Know Before Running a Half Marathon

Signing up for your first half marathon is the easy part. Knowing what actually matters in the weeks before race day is where most first-timers waste energy worrying about the wrong things. Here are the seven things worth knowing before you start training in earnest.

1. You Don't Need to Run the Full Race Distance in Training

Beginners often assume they need to cover 13.1 miles — or more — before race day to be ready. You don't. Most half marathon training plans peak with a long run of 10 to 12 miles, two to three weeks before the race, then taper down. Your body carries enough fitness from that peak long run, combined with adrenaline and taper rest, to cover the final 1 to 3 miles on race day itself.

Try to keep a conversational pace, both during training and your race.

2. Train at a Conversational Pace Most of the Time

The majority of your training miles — long runs and easy runs alike — should happen at a pace easy enough that you can hold a conversation while running. Use the talk test rather than obsessing over your exact per-mile split: if you can speak in full sentences without gasping, you're in the right zone. That said, conversational pace shouldn't be your only gear. Add one or two dedicated speed sessions a week (intervals or tempo effort — speed workouts for distance runners has specific sessions with paces and reps) so you're not just building endurance without building speed. A pace calculator can show you roughly where an easy, conversational effort should fall for your fitness level.

3. Long Runs Get Boring — Plan for It

As your long runs stretch past an hour, the miles can start to drag. Running with a group turns the boredom into the best part of the week, and even solo, breaking a long run into segments (by mile marker, by neighborhood, by podcast episode) makes the distance feel more manageable than treating it as one unbroken slog.

4. Chafing Is Common — Prevent It Before It Starts

Chafing comes from repeated friction: skin rubbing against loose fabric, or against itself, over the course of a long run. It shows up most often at the underarms, inner thighs, and anywhere a sports bra or waistband sits. Wear synthetic, moisture-wicking fabric instead of cotton — cotton stays wet once it's soaked with sweat, and its rougher texture makes chafing worse the longer you're out there. A thin layer of anti-chafe balm on known trouble spots before a long run is cheap insurance.

Unfortunately, not all runs happen on sunny days.

5. You'll Train in Bad Weather, Not Just Good

You can't control race-day weather, so don't build a training plan that only works on sunny days. Get outside for at least some of your long runs in heat, cold, wind, and rain rather than defaulting to the treadmill — it builds both physical tolerance and the mental confidence that you can handle whatever race morning brings. If you do train through heat, ease your pace: a widely used rule of thumb is to slow roughly 10-20 seconds per mile for every 5°F above 60°F, adjusted by feel rather than treated as an exact formula.

6. Rest Days Are Part of Training, Not a Break From It

Logging miles matters, but running every single day is a fast track to injury and burnout. Build rest days into your week deliberately — they're when your body actually adapts to the training stress you've put on it, not wasted time. For more on how mileage progression and recovery work together to prevent overuse injuries, see avoiding common running injuries.

7. Your Diet Needs to Support Your Training, Not Restrict It

Half marathon training burns real calories, and that's a reason to fuel deliberately, not to restrict your meals. Figure out roughly what your training load requires and eat a balanced diet built around it — enough carbohydrates to fuel and refill your runs, enough protein to recover, and enough overall calories that you're not training in a deficit that leaves you exhausted and slow to adapt.

Applying these seven isn't about perfection — it's about not wasting your training on the wrong worries so you show up on race day prepared, not just tired.

Frequently Asked Questions

Do you have to run 13 miles before a half marathon?

No. Many beginners assume they must cover the full race distance or more before race day, but that is not necessary. You can be in a comfortable position to participate in a half marathon if you can run or walk for about 10 miles. Physical preparation matters, but there is no need to run 13 miles or more in training to be ready for the race.

What pace should you train at for a half marathon?

During training you should maintain an easy, conversational pace, one relaxed enough that you can breathe easily and hold a simple conversation while you run. Rather than worrying about your exact pace per mile, use that talk test to gauge effort. It is still worth adding some speed work once or twice a week, but long runs and easy runs make up most of your training and help prevent overtraining.

How do you prevent chafing while running?

Chafing comes from repeated motion and skin rubbing against loose fabric or other skin, and it is common during long training runs. To prevent it, wear suitable running clothing made of synthetic material that wicks away moisture. Avoid cotton, because once it gets wet it stays wet for a long time and its rough texture can leave your skin raw as it keeps rubbing.

Do you need to run every day to train for a half marathon?

No. Logging miles is important, but running every single day leads to injuries and burnout. Anyone training for a half marathon needs some rest days built into the week so the body can recover and adapt. Balancing running with rest, along with easy runs and occasional speed work, keeps you healthier and more consistent throughout your training.