As important as they are, speedy intervals don’t need to dominate your training to be effective. Even world-class marathoners still run easy 80 percent of the time. The key is to make some of that other 20 percent significantly faster than marathon pace.
Take a look at this 6-week workout progression that a marathoner might start five months out from race day, for example.
5 x 800 @ 5K pace
4 x 200 @ mile pace
16 x 200 @ mile pace
6 x 150m @ 800m pace
12 x 300 @ mile pace
2 x 2 miles @ tempo
8 x 100m @ 800m pace
8 x 400 @ mile pace
Note there are two distinct ways speed work is incorporated in these examples. During the odd numbered weeks, there are longer intervals between 5K and half-marathon pace followed by shorter, more explosive short intervals.
High-end aerobic goals, like increasing VO2max and lactate threshold pace, are the primary goals of these sessions with speed development secondary. During the even numbered weeks, speed development and speed endurance take center stage, and this is reflected in both the pace and duration of the intervals.
Speed and efficiency can also be increased through much shorter, more intense sprints. These repetitions last no more than 15 seconds and are sometimes categorized as “anaerobic alactic” sprints because they require no oxygen and leave no byproducts like lactic acid.
Maximal effort can only be fueled by the phosphocreatine system; this taps out after 10-15 seconds. To make the best use of this system, run at 100 percent, all-out capacity on a steep hill for 10 seconds at a time. Climbing will force you to activate your glute muscles and drive your arms more powerfully as compared to flat land, enhancing the effect.
To recover from these sprints and restore your supply of phosphocreatine, you’ll need to rest for at least 1-2 minutes after each sprint.
Powering Away to a Big Fall Marathon
Hill sprints and 400-meter intervals won’t get you a marathon PR by themselves. You still need the long runs, the long tempos and good health to run fast for 26.2 miles. But incorporating speed for the rest of this summer will break up the monotony, increase your potential, and make you a better overall runner.
I can’t promise you an Olympic medal like Kirui, but it never hurts to train like a champion.
By Philip Latter. Latter is a former senior writer at Running Times and co-author of Running Flow and Faster Road Racing. His work has also appeared in Runner's World, runnersworld.com, and ESPN.com. He currently coaches athletes at The Running Syndicate, in addition to his day job coaching high school runners at Brevard High School (NC).