Brick Workout Calculator

A brick workout combines two disciplines back-to-back — most commonly cycling followed immediately by running. The name is said to come from the feeling of 'bricks' in your legs when you start running after cycling. Brick sessions are essential for triathlon preparation because they train your body to switch efficiently between disciplines.

During cycling, your body recruits different muscle-fiber patterns and blood is concentrated in your quads and glutes. When you switch to running, your body must rapidly redistribute blood flow and recruit your hamstrings and calves. This neurological and cardiovascular adjustment causes the heavy, sluggish feeling known as 'brick legs,' which typically fades after the first 5–10 minutes of running.

Beginners typically slow down by around 8–12% compared to their fresh-legs run pace, intermediates by 5–8%, and advanced athletes by 3–5%. The exact adjustment depends on how long and intense the bike segment was. Use the suggested brick run pace from this calculator as your starting target and adjust based on feel.

For Olympic-distance preparation, a typical brick session might be a 30–40 km bike ride followed by a 5–10 km run. Total duration usually falls between 90 and 120 minutes. The bike segment should be race-effort or slightly below, while the run should simulate the pacing stress of going into the run on tired legs.

A common strategy is to hold back slightly on the bike — riding at around 80–85% of your maximum sustainable effort — so you preserve running capacity. If you go too hard on the bike you will blow up on the run. Incorporate race-pace bike efforts in your brick training to learn exactly where your threshold lies.

Most triathlon coaches recommend 1–2 brick sessions per week during the race-specific build phase. Beginners may start with just one per week, while advanced athletes sometimes do two. Quality matters more than quantity — a focused brick with proper intensity gives more benefit than grinding through extra volume.

The Quarters strategy divides your race into four equal time segments. The goal is to feel controlled in the first quarter, settled in the second, strong in the third, and to give everything in the fourth. Practicing this discipline in brick sessions trains you to resist going out too hard, which is the most common race-day mistake.

Yes — a duathlon is structured as run-bike-run, but you can use this calculator for any bike-to-run segment. Simply enter the distances and paces for the bike-to-run portion of your duathlon training session to get segment times and a brick run pace recommendation.