March is not that far away. In fact, most competitive cyclists train pretty hard through most of the winter to prepare fr early season road races that happen in late march or early april. However, hard work needs to be done with a solid base, or else you risk injuring yourself. So, I am not going to recommend my personal winter training plan to you. INstead, I am going to recommend that you just "ride lots". Build your miles progressively and ride whenever your want. If you need a rest day, your body will tell you. If you want to get on your bike, do.
If you can get about 1000mi under your belt between now and the beginning of Arpil, you are doing well, and can start thinking about doing harder, more specific work. For a triathlon (essentially a time trial), you are going to want as high of a lactic threshold (LT) as possible. Generally 2x20min intervals are recommended to boost LT. You can incorporate these into your training in April, and if you are consistent with your training, doing 2x20s twice a week for the month of April, you should see the gains in time for your early season tri or duathlon.
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