This is my 2 month Fondo plan purely using perceived exertion, so no need for smart trainers, or any special equipment.
All you need is a basic turbo, rollers, or exercise bike.

Perceived Effort scale (RPE)

1-2 Very easy, hardly an effort

3-4 Moderate, conversation pace

5-6 Tempo, difficult for extended periods, but not exhausting

7-8 Difficult to talk, threshold at 7, sweet spot at 8

9 Extremely hard, 30-40 second efforts

10 Flat out sprint

Although this plan is aimed at those riding indoors, it can be used for shorter outdoor riding.

This has been tailored to work as a build with medium stress levels to help keep fitness moving forward, but not stress the immune system.

Each week has a nice progression working from tempo, into sweet spot, and finally adding some threshold workouts in.

There's also a strength program which can be done from home using weights, kettlebells, or simply body weight if that's all you have available.

The aim of this is to continue to build fitness and form, also a great structure to anyone targeting fondos/sportives.
Now's the time to stay healthy and active more than ever before.

I'm happy to answer any questions, just email me on andrew@wattsupperformance.com