Mixed Relay Simulation: 300m Swim / 8km Bike / 2km Run x4 Brick Session

Session Overview

A short, sharp brick session that simulates the super-sprint format used in World Triathlon mixed relay racing: repeated efforts of 300m swim, 8km bike and 2km run, raced back-to-back with minimal recovery. It’s a brutal test of your ability to switch disciplines and hold pace when your legs are still loaded from the previous leg — ideal for anyone racing a sprint or super-sprint this season, or a club member training with a relay team.

What You’ll Need

• Access to open water or a long pool session (300m repeats)
• Bike set up and ready to mount straight from the poolside or lake exit
• Running shoes staged at your transition point
• A training partner or small group — this session is far more realistic raced against someone else

Warm-Up (12 minutes)

200m easy swim building to moderate effort, followed by 5 minutes easy spinning on the bike to open the legs, then 3 minutes of running strides to prime turnover before the first rep.

Main Set

Complete four full rounds of the sequence below, transitioning as quickly as possible between disciplines — treat each transition like a race-day tag exchange, not a rest stop.

• Swim: 300m at 5K/10K race pace effort
• Bike: 8km hard and steady — treat it as a group ride pace if training with others, holding position rather than isolated time-trialling
• Run: 2km off the bike at 10K race effort
• Recovery: 2-3 minutes walking/easy spin between full rounds — enough to reset, not enough to fully recover

Cool-Down (10 minutes)

Easy jog or walk for 5 minutes followed by 5 minutes of easy spinning to flush the legs. Stretch calves, quads and hip flexors once heart rate has settled.

Coaching Notes

• The first round always feels manageable — the session is designed to bite on rounds three and four, so hold something back early rather than blowing up by round two
• Common mistake: treating the bike leg as an all-out solo effort. If training in a group, practise holding a wheel and riding smoothly in a tight pack, since real mixed relay bike legs are draft-legal and tactical
• Scale down: drop to three rounds, or extend recovery to 5 minutes between rounds, if this is your first time attempting the session
• Target RPE 8/10 on each individual leg, dropping no lower than RPE 6 even on the final round — this should feel uncomfortable by design