A Practical Guide To Heart Rate, Pace And Recovery Data

The transition from the bike to the run, often called a brick session, produces some of the strangest data in triathlon. Legs that were turning smoothly on the bike feel heavy for the first minutes of the run, and the watch reports a pace and heart rate that look wrong. They are usually correct, only unfamiliar.

Why the first kilometres of the run look odd

After cycling, blood flow and muscle use are different from normal running, so the first kilometres often show a higher heart rate for a lower pace. Most athletes settle after a few minutes. Cadence tends to be quick at the start and then relaxes. Reading the first five minutes of a brick run on their own gives a distorted picture of the whole session.

Look at the middle, not the start

A better approach is to compare the middle and final sections of the run with a standalone run at similar effort. If those match after the settling period, the bike did not cost much. If they stay much slower, the bike may have been too hard. Practising the transition regularly in training also teaches both the legs and your own expectations what a normal brick looks like. In the same spirit, a page such as the Spinando Casino app is best read after the opening moments, once the figures have settled and the pattern is clearer than the first reading.

The transition itself belongs in the data too. The time spent changing shoes and helmet, the walk to the run exit and the first few steps can be recorded as a separate segment by many watches. Seeing this time as its own number makes it easier to tell whether a slow first kilometre was a running problem or a logistical one.

Fuelling during the bike changes the run. An athlete who drank and ate steadily will usually settle faster than one who arrived at the run already empty. The data will not say which unless you record what you consumed, and a brief note in the log is again the simplest solution. Over a season these notes build a personal record of what works.

Anyone who follows betting markets at a triathlon should settle a budget and a time limit before the gun, as the bike-to-run change can reshuffle positions and tempt quick decisions. Keep stakes modest and take regular breaks.

Brick data helps us see how the body adapts between disciplines. It cannot predict a result, and the reasonable use is to compare similar sessions across several weeks.