This is a supplemental strength training plan that uses only body weight and focuses on core work and leg strength. You could do it on its own, but the idea here is to layer this onto whatever aerobic training you're doing (running, cycling, etc.)
It can be a useful if you're a runner, cyclist, or triathlete who wants to build strength and strength endurance without having to buy equipment or go to a gym. This will help you most during earlier in your training macrocycle (base/foundational or build training) when building overall fitness before doing a harder block of peak workouts. So, if you're building up through the late fall or winter months, or you're >10-12 weeks out from a goal event and want to build strength, this could be a useful add-on to your aerobic work.
The program starts pretty easy and ramps up gently over the course of the eight-week block. The Thursday session is the one that is the most demanding on your legs and sees the most progression. So you should consider doing your key mid week session Tues, Wed, or Thurs (before the strength session), depending on your schedule. If you have two mid-week workouts, then you might consider doing your workouts on Tues/Thurs and taking Mon, Wed, and Fri as rest or easy days. The weekend should be open for whatever endurance training you want to do.
If you want to extend this program to keep building or maintaining any strength gains during a longer block of training, then you can repeat the last few weeks of this program for many more weeks if you're still a ways out from your goal event and it balances well with your other training demands.
After racing successfully for many years, I've been very fortunate to be able to perform at a high level myself, and now enjoy supporting athletes as they work to achieve their own success across all levels of performance. I've been a competitive athlete for many years and am grateful to have supported other athletes to get fitter and stronger as well as win multiple national championships, win or podium in their age group, or simply finish strong at their goal events.