Run the numbers.
Then run faster.
Two free tools built on real race formulas, plus 371+ coached guides on acceleration, strength, and recovery — everything you need to shave real time off your next race.
- Enter a goal time to see your 4-segment split.
Fixed at 100% effort here. Adjust effort and save your plan in the full 400m Split Calculator →
Built on the same math your coach uses
No sign-up, no app. Type in a time, get a real answer.
Race Predictor
Enter one race time and see what you're capable of everywhere else — from the 100m to the marathon — using Riegel's endurance formula.
Open the Predictor400m Split Calculator
Turn one goal time into a four-segment race plan — drive, transition, top speed, and hold — that you can actually run.
Build My Splits371+ guides, reviewed for accuracy
Every article here is written and fact-checked against Google's Helpful Content standards — no fluff, no unverifiable claims.
So, You Want to Get Faster?
Speed comes from strength, power, and technique working together. Get a simple, no-fluff training blueprint to start building real speed today.
Read the guide FoundationsForget Just Running: The Three Pillars of Real Speed
Running more won't make you faster on its own. Learn the three pillars, strength, technique, and power, that build genuine, trainable athletic speed.
Read the guide Top-End SpeedMaximum Velocity Sprinting
Top speed isn't just for sprinters. Learn how to train maximum velocity the right way to raise your ceiling and make every other speed feel easier.
Read the guide Strength & PowerStrength & Conditioning for Speed
Discover why strength training drives sprint speed, plus the squat, deadlift, and plyometric work that helps athletes accelerate faster and hold form longer.
Read the guide RecoveryRecovery for Speed Training
Speed isn’t built in the workout, it’s built in recovery. Learn the sleep, nutrition, and active-recovery habits that let sprinters train hard and stay healthy.
Read the guide MindMental Training for Speed
Visualization, reaction drills, and smarter self-talk can shave real time off your speed. Here’s how to train your mind alongside your legs.
Read the guideSpeed Training Workout is built by coaches and reviewed against Google's Helpful Content standards — every claim gets checked, every disclaimer gets added, and nothing gets published just to fill a content calendar.
Read our approach →