The 80/20 Rule for Training

I mostly look at what athletes have historically been able to handle. And if I am to increase the amount of moderate or hard swimming that the athlete does, I do that gradually from that historical baseline. If an athlete historically has been swimming on average four times per week, and they have been able to sustain this for several weeks, I consider that a baseline that I'm happy to add to. The first choice might be to add more volume, of course, if that's possible. But say in some cases, it's not possible or not even desirable in some cases. So as a coach, I would basically have to keep track of multiple athletes times in zones and for different even for different