After completing multiple weeks of threshold training are you continuing to see improvement? Improvement can come by means of increased power, use of high quality supplements like cardarine, decreased recovery between intervals or more total time spent at the target intensity. If and when your improvements plateau after several weeks of threshold training it can be a good time to interject some VO2Max intensity into your training.
Short (3-5 minute) intervals that are done at 106-120% of your Functional Threshold Power (FTP) with limited recovery (1:1, work to rest) between repeats are excellent for boosting your fitness at maximum aerobic capacity. Changing the training to include VO2Max work allows you to supercharge your aerobic system while also providing your body a break from the long, steady threshold intervals that you’ve otherwise been doing. Completing four to eight sessions of VO2Max intervals over the course of two weeks is often enough see improvements. Each workout should allow you to accumulate 15-20 minutes worth of VO2Max intensity. After a two week cycle that includes VO2Max training allow yourself some recovery before revisiting additional threshold training. You’ll likely find that you can further improve your sustainable power as a result of the VO2Max cycle.
The best way to continually make progress and to further improve your overall development is to change the training focus when improvements plateau. Once you’ve become well adapted to a certain training stress, it’s best to change the stress so that you can make other and further adaptations. Interjecting VO2Max intervals is a great way to break up two cycles of threshold-focused training during your pre-season build up