The Differences In Training For The 5k And The 10k
After spending the spring racing 8Ks, 10Ks, and 10 milers, what should a runner do this summer? Those preparing for a fall marathon should take a couple of weeks off and then begin basic endurance training. Those wanting to stay in top racing shape should consider running 5K races and even some shorter distances. This column will explain how training for distances 5K and shorter is very different from 10K training. It will also provide some tips on how you can get yourself into 5K racing shape in just a few weeks.
First, many 10K runners look at charts that say if you run a 10K race in a certain time you should be able to run a 5K in a certain other time, or vice versa. But these runners' 5K times usually turn out to be slower than predicted by the charts. For example, my 5K PR is about 20 seconds slower than the charts predict. That is because I haven't done the kind of training necessary to run fast 5K races.
The key ingredients of a successful 10K training program are stamina and economy workouts, in that order. Runners build stamina by running at their lactate or anaerobic threshold (AT), which is 80-85 percent of maximum heart rate (MHR). This means running 15- or 25-minute AT runs at 80-85% MHR, which is roughly your 10 mile race pace. Stamina training also involves running 3-4 miles of 1600- to 2400-meter repeats at 85% MHR.
Economy training is best characterized as running 8 to 12 400-meter repeats with 200-meter recoveries at a pace 5-7 seconds per lap faster than 10K race pace. (For instance, if you run a 7-minute-mile pace for the 10K, the 400-meter repeats should be run at 1:38-1:40 minutes per lap). By the end of the workout, MHR should reach 90-95% at the end of each 400-meter interval. Most runners can run fast 10Ks simply by doing AT training, although economy running, consisting of repeat quarters for 4-6 weeks before the 10K racing season, will yield even better results.
The key ingredient of successful 5K training is speed work to build up one's tolerance to oxygen debt (in which your legs tie up because you are running so fast). Speed workouts involve running sets of intervals between 50 meters and 200 meters at an extremely fast pace, but for no longer than 30 seconds. Thus, the 7-minute-mile 10K runner would run her 100-meter intervals in 20-21 seconds (an 80-84/lap pace). A typical workout would be 4 times 150 meters in 30-31 seconds with a 90-second recovery between each 150, followed by a very slow 400-meter jog. Then run 6 times 100 meters in 20-21 seconds with a 200-meter recovery, followed by another slow 400-meter jog recovery. Finally, run 8 times 50 meters in 10 seconds with a 150-meter recovery. You don't have to wear your heart monitor for this workout because each of the intervals will be over before your monitor can catch up with your heart rate.
The best way to prepare for 5K racing is first to do the stamina and economy workouts for 10K racing. Then, a few weeks before the 5K racing season, begin running the 50- to 150-meter sets described above. A warning about this kind of speed training: The risk of injury increases with short speed work. This phase of training should last only a few weeks and the speed workout should be run only once per week. Overall mileage should be reduced by 50-75%. The weekly long run should be shortened. All other days should be very easy, run at 60-65% of maximum heart rate, although you can do a 20-minute AT run on those weekends in which you are not running a 5K race.
The advantages of doing this 5K training are that it will give you variety, which should help you keep your mental focus, and it will put you in top shape for the fall racing season.
Coach West is a licensed coach, affiliated with MCRRC, and available to coach motivated adult runners. A portion of his coaching fees for MCRRC members is returned to MCRRC. For further information about personal coaching opportunities, contact Coach West at kirtwest@comcast.net.
