For marathon training, I think my longest tempo was 12 miles w/7 miles at 15k-HM pace (usually closer to HMP). In that case, I did 3 warm up, 7 @ tempo, 2 cool down.
I apply that ratio to any tempo distance. A 7 mile tempo would probably be 2 mile warm up, 4 @ tempo, and 1 mile cool down. My tempo pace is faster than goal race pace.
I only did tempo runs during my last training cycle so take my words with a grain of salt. They started at 5 miles ( warm up, 3 miles @9:44, cool) and ended with 6 miles ( warm, 4 miles @ 9:30 cool). I did my middle miles about 30 seconds faster because I gunning for a sub 2:00.
Mine would vary in length/format based on whatever the running group gurus had written on the schedule for that week...but generally a mile warmup, anywhere from 4-7 miles of speedwork/tempo, and a mile cooldown. The fast part could be anything from mile repeats to Yasso 800s to 2 mile repeats and so on with breaks of varying length in between...the mileage for the fast part would start out shorter at the beginning of the training cycle and build from there. Speed was based on your goal race pace and they'd have you add or subtract 30-60 seconds from that based on the workout.
I'm not sure how well that's going to work out for me this summer since I won't be doing the Weds evening group speed workouts anymore, but Imma try.
I'm doing one tonight I'll only do about 10 minutes at tempo (8:15) and another 10 near tempo (8:30), (10 min easy, 5 min @8:30, 10 min @8:15, 5 min @8:30, 10 easy) but I'm really out of shape right now. my goal is to work up to 60 min @ tempo by the end of the summer. I find it easier to do these by time rather than distance.
I usually do a 1-2 miles warm up 3-4 tempo miles and 1 mile cool down. I almost never actually made it to half marathon pace. I was usually 15-30 seconds slower than goal pace.
I wanted to add that I never hit my goal paces in the Summer. NEVER. Summer marathon training is a complete and utter mind fuck. But, it does make you stronger, and in the fall you'll start hitting those paces. It is a good idea to go by 1/2 pace effort or use a HRM. If you are hitting your paces in the Summer heat, you'll need more aggressive goals for the fall. It will be mid 80's Thurs and Fri, so the Summer talk seems appropriate I also never hit my goal paces on the treadmill b/c, well, they suck.
Are you talking about marathon training tempo runs or just tempo in general?
I haven't done tempo for my marathon stuff yet (I will be this training cycle), but the format I usually follow for shorter distances is: take a midweek longish run in your training plan, divide it by three. Use the first third to warm up, the second and half of the third third to run a tempo pace that's the one faster than whatever race you're running (so for marathon, it's HMP, for a half it's 10k, etc), and use that last half of a third to cool down. It's kind of a mutant Hal Higdon tempo run plan.
Whatever. This is helpful. I think I'm going to steal it.
I'm reading Pfitz book right now. I usually do them based on HH instructions. But I don't think I've been doing them fast enough. I've been maxing at goal marathon pace, not goal HM marathon pace.
Right now I do one once every three weeks (I rotate between 3 speed workouts). 6 miles with 1 warmup, 4 tempo, 1 cooldown. During marathon training I was doing them per Pfitz.
I usually peak faster than HM pace, somewhere between where Pfitz says my LT should be and where McMillan says it should be. If I have a lot of steam left at the end, I keep speeding up. I think my average tempo pace recently is about 7:55/mi.