Tempo runs are one of the simplest, but also most beneficial workouts you can do. I first heard about them through Coach Bill Dellinger at a Coaching clinic in about 1976. I began using his 10k drills the next year, and did not get the hang of tempo runs until late in my racing career.
Tempo runs, like fartlek, come in all shapes and sizes. Ben Rosario, the coach of HOKA NAZ elite, uses them with his marathoners. Consider this, Stephanie Bruce ran marathons in November and December, scoring a big PB in December. In January, Stephanie ran her first 5000m indoors and ran a PB of 15:44! Tempo works!
Week 4, 2019 Track buildup-nothing in spikes, flats all week
Monday-warm up, 45 minute Holmer fartlek, go out easy 22.5 minutes, come back strong, 4 x 150m stride outs, core training, cooldown
Tuesday-warm up, 20 minute temp run, run at 30 second per mile above your 5k current race pace, 4 x 150m stride outs, cooldown
Wednesday-warm up, 50 minute run, 4 x 150m, core training, cooldown
Thursday-warm up, 20 minute run, 8 x 200 m, good pace, 100m jog, 20 minute run, 8 x 350m, good pace, 100m jog, 20 minute run, 8 x 200m, good pace, 100m jog, 1 mile easy, then cooldown.
Friday-warm up, 50 minute run, 4 x 150m, core training, cooldown
Saturday-warm up, race 800m, 1000m or 3200m, cooldown. Or, run 45 minutes easy.
Sunday-warm up, 55 minutes, cooldown