You will need a trainer, bike, power meter, cadence sensor, heart rate monitor, internet capable electronic device and a Zwift subscription to start Zwifting, but don’t forget to add a fan. For years I would just open a window to try to keep cool during my indoor training sessions. I never even thought of using a fan.
Adding a fan made a huge improvement to my indoor training experience. One of the many pleasures I love about cycling is that cool breeze generated while pedaling. However, when I started training indoors, I never even considered that I could recreate that experience by simply adding a fan.
Although I use a Wahoo KICKR HEADWIND with a smart fan that can be controlled by my speed or heart rate, any good adjustable speed fan with a fan head that can direct the breeze on your torso, where you need it most, can be used.