2/27/2006: Ran 3 miles today, but did 400m repeats. I jogged 400m, then alternated running hard with recovery every other 400m. The recovery would be a period of walking and then jogging the rest of the 400m until it was time for hard run again. Worked out pretty well. I could definitely feel the difference and my time was pretty close to what I can do 3 miles at a steady pace. Ran the mile loop by my house 3 times. Average heart rate was 159.
400m Marker	lap time	split time	heart rate at marker
1	2.04	2.04	163
2 (hard)	2.25	4.29	174
3	3.09	7.38	160
4 (hard)	2.31	10.09	176
5	2.41	12.49	159
6 (hard)	2.40	15.29	176
7	3.30	19.00	159
8 (hard)	2.35	21.35	174
9	3.06	24.41	149
10 (hard)	2.36	27.17	173
11	3.24	30.42	159
12 (hard)	2.49	33.30	173