4 miles easy/race pace combo

4 total miles today with a combination of easy pace and race pace. First 1/2 mile easy in 5:12. Next 1 1/2 miles race pace in 14:04 (9:23 ppm) followed by 1/2 mile easy in 5:23. Next was 1 mile race pace (legs wouldn't respond) in 10:05. Last 1/2 mile easy (very easy) in 5:36 for a total time of 40:20 (10:05 ppm). Although the 1 mile race pace was slow, maximum effort was put forth.