Why are we doing this again?

I don't know what happened this morning, but the tempo run was hard! I think I'm still a bit sore from hill running last week and I was sore from the 10 mile run on Saturday, AND I was TIRED! It seems like last week, the run was hard, but not seemingly impossible from the first step to the last. We did slow it down from last week, and I think we were closer to a race pace we could keep up for an hour (8:33; although as Steph said, it would be a painful hour), but still the run killed me.

So to renew my motivation for the Monday workouts I did some research.

Benefits of Tempo Running:
http://www.runnersworld.com/article/0,7120,s6-238-263-265-6141-0,00.html
First: Training variety improves your fitness, staves off injuries, and keeps motivation high.
Second: Tempo runs make you a less fatigued marathoner.

Benefits of Speed Training:
http://www.sportscoach.netmx.co.uk/modules.php?op=modload&name=News&file=article&sid=1066&mode=mode=thread&order=0&thold=0&POSTNUKESID=9cce284756e1c6a47764a3b4246de95a
Speed training works on three things essential for improving marathon speed: lactate threshold, VO2 max and leg speed.
- Lactate threshold: Muscles can burn glucose two ways, aerobically (with oxygen) and anaerobically (without oxygen). In the anaerobic version, short-term energy stores are depleted rapidly, and lactate builds up in the muscles. At that point, you can't go any farther. Running long distances uses the aerobic system. But eventually, the lactate begins to accumulate in the bloodstream. "It's that burn you feel at the end of a race," says Jake Goldsborough, who helps run Fleet Feet's summer speed work sessions. But by doing interval work, you help your body learn to deal with that lactate buildup, says LeAnn Harris, an exercise physiologist and manager of the BJC WellAware Center.
- VO2 max: VO2 max is the maximum amount of oxygen you can transport to your muscles. The science regarding this can get a little confusing, says Harris; just know that numerous studies show that you can increase your VO2 max by working out at higher intensities. And the better shape you are in, the better your capacity for VO2 max, says Harris.
- Leg speed: When you train slowly, you only activate your slow-twitch muscle fibers, so the fast-twitch fibers stay untrained. By sprinting or running faster you activate your fast-twitch fibers, which can help you toward the end of a long run.

Conclusion: Monday workouts will keep us from getting tired as soon as we would otherwise and when we've used up all our regular muscle and stamina, we might be able to tap into a small reserve we build from speed training. Sounds important. These might be the workouts that really make our marathon experience. Now if I could just figure out the benefits of the 5:30 a.m. spinning class . . .