6m with 5x 1km reps

Excuses:
Too tired, not slept enough
Too hungry, not enough breakfast and too long from breakfast to reps
Too hot, seriously hot today
Too windy, out ok, but back was bad
Too much too soon. Jumping from 400m sprints to 1,000m efforts was too ambitious
Not enough recovery between reps, 1min is not enough

Still, managed three out bound ok ones, then thought I would die on the return.

Oddly the hrt data pointed to being able to sustain it, but I could not.

3:49
3:50
3:59
4:37
4:25

So Jason, if you want to do 5km in under twenty you need to do better than me at this session. 18min in zone 5 and 8 in zone 4. That's about all there is to say.