Notes
approx 28 degrees at elevation in joburg. couldn't find a flat run course, so did the best I could. Here are the results:
times for intervals are km times/HR
1:13 total time for 15km
2km warm up
1 - 3:49/154 (slightly uphill)
2 - 3:46/164 (slightly downhill)
3 - 5:44/136
4 - 3:40/161 (slightly downhill)
5 - 3:50/170 (slightly uphill)
6 - 6:06/135
7 - 4:00/161 (slightly uphill)
8 - 3:46/169 (slightly downhill)
9 - 6:23/137
10 - 4:05/162 (slightly uphill)
11 - 3:48/168 (slightly downhill)
12 - 6:00/136
1km cool down