Post Illness
Before I start, always check with your doctor before you resume training after illness.
This is the time of year where at some point most of us will get the flu or a cold, some will have a few days off, but most will a have a week or more off, the mistake most people make, in the past myself included, is on day one of feeling better we try to resume training where we left off pre illness, but I’ve found this just leads to problems. I’ve found the safest way is for every week you have off due to illness, you should have equivalent amount of time of preparation to start training, where you ride but for no real training affect, but ease yourself back in some easy short recovery rides for 2 to 3 days, giving your body time to catch up with it’s self and naturally find it’s true level of fitness. After this if you feel ok slowly building the time and intensity up. If you use power you will naturally see the watts increase over your preparation to start training period, so by the end of this period you will see similar numbers to the ones before you were ill, normally at this point you feel like an athlete again and can resume normal training and there is also less chance of you become Ill again.
Also know what your healthy resting heart rate is, ie resting HR first thing in the morning, so take it while you are fit and healthy, normally when ill it is elevated by 10 beats or more, you can use this as part of your recovery, the closer it gets to normal the better idea you'll have when to resume training.