I have noticed a lot of questions regarding when to change up workout routines. I will try to briefly explain the concept of peroidization.
Peroidization simple explained is the concept of changing one's exercise routine in-order to prevent the body from adapting to exercise thus causing a plateau in gains. Most peroidization programs are based on 4 periods a year changing once every three months. Why three months you may ask, well according to most of the current and landmark literature. It takes the body about 12 weeks to adapt fully to any new exercise routine. This means that after the 12 weeks the body has adapted (become use to) the current stimulus that its been exposed to. This adaptation causes the body to no longer grow or improve. This goes for resistance training along with both anaerobic and aerobic exercise. What this all means is that if your on a new exercise program after 3 months it will no longer produce the same response in the body as it did when you first started it.
How do I get my body to respond after it adapts?
This is simple you just change your exercise routine to something that the body hasnt seen before. For example I work with lots of endurance athletes, one period maybe an off-season building program. Which would consist of a runner running 90 miles a week with 4 days of weights. The next period which would be contest prep would consist of 120 miles a week with 2 days of weights for maintenance only. Then we would of course have a rebuild and rest period followed by a gradual build up period.
Now of course the three month rule isnt really a rule its more of a guideline. Some programs for individuals will run only 8 weeks some will run longer. Everybody's body is different thats why its important to listen to your body and know when a change is needed. I have wrote programs for athletes that run as long as 15 weeks which is the extreme end in my opinion. If you want to learn more about peroidization and its applications the two best places to look are the websites for ACSM and NSCA.
Thanks and hope this helps
MS