Five Repeats, 28 Degrees and a Lesson About Fuel

The next quality session consisted of five 1,000 metre repetitions with jogging recoveries.

The temperature was 28°C. I completed all five repetitions and rated the session 7.5 out of 10. It was hard, but not an all out effort.

The data

Metric	Result
Distance	Approximately 10.3 km
Time	1:01:39
Average pace	5:59/km
Average heart rate	142 bpm
Maximum heart rate	167 bpm
Average power	253 W
Maximum power	346 W
Elevation gain	9 m
Temperature	28°C
Perceived effort	7.5/10

The five faster blocks were clearly visible in the heart rate and power data. Heart rate climbed into the 150 to 165 bpm range during the repetitions and dropped during the recoveries.

There was no dramatic cardiovascular collapse. The final repetition was difficult, but the overall structure remained intact.

What the coach saw

ChatGPT considered the workout a successful quality session. Completing all five repetitions with jogging recoveries created a higher training density than walking or stopping between efforts.

The heat was again treated as an additional load. The coach did not interpret the average pace as a direct measure of what I could do in cooler conditions.

The next run was reduced to a genuinely easy 8 kilometres. The planned tempo run later in the week was also capped rather than extended.

The part the workout data did not explain

About an hour after finishing, I began to feel nauseous. I had eaten very little before the session.

The likely combination was heat, fluid and salt loss, and insufficient energy intake. I cooled down indoors, drank slowly and ate a small amount of easily digestible food.

This became a practical lesson for future quality sessions. Hard running in hot weather is not the right time to test how little food I can get away with.

The coach recommended a small carbohydrate based meal or snack before demanding workouts, followed by fluids, carbohydrate and protein afterwards.

The interval session itself was good. The preparation around it was not.