30 weeks to sub 36 10k

[meuser]

Day 19 - 4k Time Trial

Total Time, Avg HR, Max HR
15:30.4, 173, 183

Split, Time, Avg HR, Max HR
1, 3:55.7, 159, 172 (9.5)
2, 3:54.7, 174, 177 (9.5)
3, 3:50.5, 178, 181 (9.7)
4, 3:49.5, 181, 183 (9.7)

1 cycle down. 10 seconds fast than my last 4k time trial.
Unless you recommend something else I will start another 40min 10k cycle.

Also, do you recommend any supplements during this phase of training?

Thanks!