1200m (3 laps) Lactate Threshold Intervals - this workout is meant to increase your ability to run at faster speeds without suffering blood lactate accumulation. The pace set for your workout is about 15-20 sec per mile slower then your 5K race pace (comfortably fast or conversation pace).

How many 1200s?
If you average;
20-29 mi/wk do 3
30-35 mi/wk do 4
36-44 mi/wk do 5
45-50 mi/wk do 6

Recovery between intervals are a short 200m jogs.

Suggested times based on your 5K race time

5K
Race
Time 1200 M 400 M
-------------------------
m.sec m.sec m.sec
-------------------------
30.40 7.42 2.35
29.05 7.21 2.27
27.39 7.00 2.20
26.22 6.42 2.14
25.12 6.24 2.08
24.08 6.09 2.03
23.09 5.54 1.58
22.15 5.42 1.53
21.50 5.36 1.51
21.25 5.30 1.49
21.02 5.24 1.48
20.39 5.18 1.46
20.18 5.12 1.44
19.57 5.09 1.43
19.36 5.03 1.41
19.17 4.57 1.40
18.58 4.54 1.38
18.40 4.48 1.37
18.22 4.45 1.35
18.05 4.42 1.34
17.49 4.36 1.32
17.33 4.33 1.31
17.17 4.30 1.30
17.03 4.27 1.29
16.48 4.24 1.28
16.34 4.18 1.26
16.20 4.15 1.25
16.07 4.12 1.24
15.54 4.09 1.23
15.42 4.06 1.22
15.29 4.03 1.21
15.18 4.00 1.20
15.06 3.57 1.19