In short, it depends on the experience of the athlete and the type of workout he or she is performing.
It’s the question all runners want to know the answer to: “How long will it be before I see the benefits from my workout?”
Unfortunately, like most aspects of running and training, there isn’t a quick and easy answer.
Most experienced runners have heard that it takes 10 days to realize the benefits of a workout. While I agree that this is a good rule of thumb to follow, especially during the taper phase of a training plan, it’s not a very accurate measurement of how your body responds and adapts to a myriad of different training factors. For example, the exact rate your body absorbs and responds to a workout is going to be influenced by the type of workout, the intensity, your recovery protocol, and your body’s own rate of adaptation.
However, while there is no universal and simple answer to this question, if we take the time to break down all the factors that affect workout absorption, you can extrapolate a fairly accurate estimation of how long it will take to benefit from each type of workout on your training schedule.