Yasso 800 Calculator

Yasso 800 Marathon Predictor

function calculateYasso() { var avg800Min = parseFloat(document.getElementById('average800Minutes').value); var avg800Sec = parseFloat(document.getElementById('average800Seconds').value); var resultDiv = document.getElementById('yassoResult'); if (isNaN(avg800Min) || isNaN(avg800Sec) || avg800Min < 0 || avg800Sec = 60) { resultDiv.innerHTML = 'Please enter valid positive numbers for minutes and seconds (seconds must be less than 60).'; return; } // Yasso 800 principle: X minutes Y seconds for 800m repeats predicts X hours Y minutes for marathon var predictedMarathonHours = avg800Min; var predictedMarathonMinutes = avg800Sec; resultDiv.innerHTML = '

Predicted Marathon Time:

' + 'Based on your average 800m repeat time, your predicted marathon time is approximately ' + predictedMarathonHours + ' hours and ' + predictedMarathonMinutes + ' minutes.'; }

Understanding the Yasso 800 Marathon Predictor

The Yasso 800s are a popular and often debated workout used by runners to predict their potential marathon finish time. Developed by Bart Yasso, the former Chief Running Officer of Runner's World magazine, this workout involves running 800-meter repeats at a specific pace.

How Yasso 800s Work

The core principle of the Yasso 800s is remarkably simple: if you can run 10 x 800-meter repeats in X minutes and Y seconds, with an equal amount of recovery time (jogging) between each repeat, then you can theoretically run a marathon in X hours and Y minutes.

• Example: If you consistently run 800 meters in an average of 3 minutes and 20 seconds, your predicted marathon time would be 3 hours and 20 minutes.
• Workout Structure: Typically, the workout involves 8-10 repetitions of 800 meters. Each 800m repeat is followed by an equal duration of recovery jogging. So, if you run an 800m in 3:30, you'd jog for 3:30 before starting the next repeat.
• Pacing: The pace for the 800m repeats should be challenging but sustainable for all repetitions. It's not an all-out sprint, but rather a pace that mimics your goal marathon effort, just at a higher intensity over a shorter distance.

Using the Calculator

Our Yasso 800 Marathon Predictor calculator simplifies this process. Simply input the average time (in minutes and seconds) you can comfortably maintain for your 800-meter repeats during a Yasso workout. The calculator will then apply the Yasso principle to give you an estimated marathon finish time.

For instance, if you enter "3" for minutes and "45" for seconds, the calculator will predict a marathon time of 3 hours and 45 minutes.

Limitations and Considerations

While Yasso 800s can be a useful tool for gauging fitness and setting marathon goals, it's important to understand their limitations:

• Not a Guarantee: The Yasso 800s are a predictor, not a guarantee. Marathon performance depends on many factors, including long-run endurance, nutrition, race-day conditions, mental fortitude, and proper tapering.
• Training Specificity: Some coaches argue that Yasso 800s don't fully replicate the specific demands of marathon running, which is primarily an aerobic endurance event. While speed work is important, long runs are crucial for marathon success.
• Individual Differences: Runners respond differently to various types of training. Some runners might excel at speed work but struggle with endurance, while others might be the opposite.
• Best Used as a Guide: Yasso 800s are best used as one piece of the puzzle in marathon training, offering a general idea of your potential. Combine this prediction with insights from your long runs, tempo runs, and overall training volume.

Ultimately, the Yasso 800s can be a fun and motivating workout that provides a rough estimate of your marathon potential. Use it as a guide to help set realistic goals, but remember that consistent, well-rounded training is the true key to marathon success.