The 400 is one lap of the track, run in your own lane, and it's the one sprint nobody can run flat out from start to finish. Everyone slows down. The runner who wins is the one who slows down the least.
That changes how you should race it. Most bad 400s are lost in the first 200, by someone who ran it like a 200.
What the 400 actually feels like
The first 200 feels easy. That's the trap. Somewhere on the second bend your legs start to go: your shoulders creep up, your stride gets shorter, and the last 100 feels like running through sand. Every 400 runner knows that feeling. Good pacing and good training are both about pushing it back as late as possible.
There's a reason it happens. A 2001 study of trained runners found that about 43 percent of the energy in a 400 comes from the aerobic system and about 57 percent from the anaerobic side. The anaerobic side is powerful, but it runs out, and that's the tying up you feel at 300. So the 400 isn't pure speed. It's speed you have to ration.
How to split the 400
Every good 400 is a positive split, meaning the second 200 is slower than the first. The only question is how much slower.
A review in World Athletics' coaching journal looked at elite men's races. Runners in the 43.8 to 44.9 range and runners in the 45.0 to 45.9 range both went through 200 in about 21.5 seconds. The faster group closed in about 23.0, the slower group in about 23.8. So the start wasn't the difference. Holding on was.
A 2 second gap between your two halves is a good place to start. Adjust it with your coach once you have your own race splits.
Two more numbers from the same journal are worth knowing. Top 400 runners go through the first 200 about 1 second slower than their best open 200, while less experienced runners are closer to 2 seconds off. And a rough way to guess your 400 potential is to double your best 200 and add 3.5 seconds. Run 24.0 for 200 and you should be capable of about 51.5.
The lap in four parts
- Blocks to 50 meters: get up to speed fast. You won't find extra speed later, so this is where you take it.
- The back straight: fast but relaxed. You're carrying speed now, not adding it.
- The second bend, 200 to 300: this is where races are won and lost. Keep your arms driving and your face loose while it starts to hurt.
- The home straight: everyone is slowing down. Stay tall, keep your arms moving and run through the line, not to it.
Clyde Hart, who coached Michael Johnson, called the ideal 400 "smooth deceleration". You're going to slow down no matter what. The goal is to do it evenly instead of falling apart in the last 80 meters.
Why lane 8 looks so far ahead
Outer lanes curve around a bigger circle, so each lane starts farther up the track to keep everyone at exactly 400 meters. Lane 8 starts about 53 meters ahead of lane 1. From an outside lane you can't see anybody. From an inside lane everyone looks ahead of you. Neither means anything until the last 100, so run your own race off the stagger. The men's world record, 43.03 by Wayde van Niekerk in 2016, was run from lane 8.
Mistakes that cost the most time
- Running the first 200 at your open 200 pace. Whatever you gain, the last 100 takes back with interest.
- Floating the back straight. Go out too soft and there isn't enough track left to make it up.
- Tightening up. Relaxed speed is faster speed, and a clenched jaw usually means clenched shoulders too.
- Skipping aerobic work. With close to half the energy coming from the aerobic side, it shows up on the second bend.
- Never checking your split. Have a coach or teammate read your 200 so you learn what your plan feels like at race speed.
How to train for the 400
Good 400 training mixes pure speed with the ability to hold it. Short, fast runs with full recovery and block starts build the top end. Runs of about 150 to 300 meters at high speed teach you to keep your form while fatigue builds. Longer reps of 300 to 600 meters are closer to what the race itself feels like, and they're the ones that hurt. Tempo running covers the aerobic side that most sprinters would rather skip. Your coach will balance these through the season, so treat this as the shape of it, not a plan.
400 or 800?
The 400 is a sprint you have to ration. The 800 adds a second lap, a standing start, a break for the inside lane and a fight for position. It also leans more on the aerobic system, about two thirds in the same 2001 study. If you're trying to decide which is harder, we made the case in the 800m, the hardest event in track and field.
The fastest 400s ever
Van Niekerk's 43.03 from the Rio Olympic final is still the men's world record. The women's record, 47.60 by Marita Koch in 1985, is one of the oldest in the sport. The US records are 43.18 by Michael Johnson in 1999 and 47.78 by Sydney McLaughlin-Levrone at the 2025 World Championships.
What to race in
At full speed on the home straight, you shouldn't notice your shorts. Our running split shorts come in a 2.5 inch and a 4 inch inseam, and any 2 shorts get the 3rd free. For cold early spring meets, our running half tights have an inseam of about 9 inches.
