Missing a workout here and there happens and is no problem. As I wrote about yesterday, just let it go and keep going with your plan. But sometimes we are forced to miss two or more full days due to injury, illness, or some other unforeseen circumstance.
I used to think that missing a chunk of time would be just like extra resting time, sort of like tapering before a race. I figured I would have more energy to jump back into my training plan after a good rest.
Based on reading and experience, it doesn’t actually work out that way, at least for me. If it is less than a week off, I can usually keep the same training plan, but when I get back to it, I do shorter workouts for about a week building back up to where I was. That may mean starting at about 50% of the time of a workout for a day or two, and then 75% and then right back to 100%. If it is more than a week, then it could mean adjusting and going back a week or two in your training plan and ultimately meaning that you just will not have hit the distance you had planned on before race day. I have done this before after an injury that kept me from running for a number of weeks–with triathlon sometimes an injury affects our ability to keep up with training in just one sport so this would apply just to that one. In that case, for example if you cannot run for awhile but can swim and bike, you can up your time spent swimming and biking to keep building fitness. Injuries and other events happen, especially when regular long distance triathlons are just part of your life, and we just have to move on.
I think, especially without a coach, we need to be cautious and listen to our bodies to determine what to do. But hopefully these tips, and the principle that you may need to reduce workouts before jumping back in, will help guide you in the unfortunate (but realistic) event that you will at some point miss some days or more of a training plan.