Part of being ready to race more often is not taking two weeks off.
Back in 2009 in a thread titled weight/timeoff Tom wrote:
Here are the facts:
Dr. Edward Coyle, among others, performed scientific research on detraining of endurance athletes, and he found that various measurable effects occured; in stages. The most important conclusion was about a 3:1 time-loss effect of detraining; meaning that for every day you rest it takes 3 days of training to return your fitness to where it was. After 4-5 days of no training, there's a rapid loss in aerobic capacity. The most important losses are enyzmes in mitochondria that process oyxgen to generate ATP - energy for work - and blood loss.
It appears that time-loss changes run in 5-day patterns. That is, every 5 days there is a huge drop or loss in key components of endurance physiology. Take the first 5 days off and you have minimal loss in aerobic capacity. Take another 5 days off (consecutively) and you lose a bunch of aerobic capacity due to blood volume losses. All the while, every day off you lose mitochondra enzymes, which have a hidden component, I speculate. (I think the capacity to sustain a power output - velocity for running or power for sports that can measure power - erodes steadily and perhaps exponentially).
Decay in performance if fairly rapid for beginning runners and not as rapid for long-time runners. However, consider 3:1 as the average. So, if you take 2-weeks off, Coyle says you'll need 6-weeks to regain fitness (back to where you were before the time-off). Consider this: You actually lost 6.666 weeks of conditioning potential. How do I get this number? I already stated that 3:1 for 2-weeks of rest required 6-weeks of training to return fitness. Now, fitness gains are at a 1:3 ratio. So, during 2 weeks off you lost ~5 days of gains in fitness (14 days divided by 3 is 4.66666; the expected gains in fitness. And, 4.666 days is 2/3rds of a week (.6666). Hence, you lost 6.666 weeks of potential fitness gains by taking two weeks off from running.
Regarding injuries: I think that two things happen. First, injuries can happen almost anytime for runners, which is a big problem. Let's say you took two weeks off, start training again and 3 weeks into your comeback you get sick or injured and have to take another two weeks off. When your injury happened, you were only 3 weeks back to getting in shape, so you really are 3.666 weeks behind (6.6666 - 3 weeks = 3.666 weeks). Taking two extra weeks off (because of an unforseen illness or injury) means you lose 2 weeks, which takes 6 weeks of conditioning to get back to where you were (which was 3.66666 behind schedule). IF you do start running at 2-weeks off (which was due to the illness or injury) you now have to train 10.333 weeks (6.6666 + 3.6666 = 10.33333 weeks) to get back to where you were before you took off the first "rest-break" of two weeks. Do you see the drawbacks of taking time off?
Remember, 90% of "time-off" rest breaks from running, when you don't have illness or serious injury, are mental. And, let's be honest, does it really take 2-weeks off to mentally get recharged? After 5 days, you are mentally fine. Look at a worse-case scenario - like racing a marathon. When people run a marathon and they push themselves to an extreme limit, they become totally drained (phyically and mentally), which is harder than normal training fatigue. And, how long is it before people who run marathons are mentally ready to return to running? Try 5-7 days. I've coached many marathon runners and very few of them want to take off more than a week. TYpically they are beat-up for 4 days and then start feeling better. Within a week nearly every one of them wants to run again. And, many despite my words of caution, start running before the week is up.
Seriously, seldom is there a "real" need to take 2 or more weeks off at the end of a racing season. At least, there is no physical reason. And, since most runners are mentally "lost" after 5 days of no running, I posit there is no real mental reason to rest more than a week, either.
To me, the better approach, borne-out from 20 years of coaching, is to take minimal time off after a heavy racing season and then leave yourself the option to take time off when you really are ill or injured. The smarter approach is to take 3-5 days off, then ease back to normal training over the next 11-9 days. By the 14th day, post-season, you are refreshed mentally and physically; yet you have lost very little fitness.
Note: many, many runners suffer injuries 5-10 days, following a a long lay-off. I have seen countless runners take two weeks off, then, about 10 days after they started running again, they hobble around; complaining of a sore Achilles, sore planatar fascia, sore hamstring or soleus muscle. It happens quite often!