Interesting article in Canada's Globe and Mail today. When I go to the gym for a spinning class I concentrate on upper body on the machines before the class because I think the cycling will look after my legs. This research suggests otherwise.

https://www.theglobeandmail.com/life/...rticle2127948/

Another benefit not mentioned and one that is vital to cyclists is bone density. But you have to lift heavy, no sissying around with the tiny weights.

Leg training is important, but I'd be wary of 'knee extensions.' It doesn't duplicate anything you do in real life and can harm your (older) knees. Stick with squats, box jumps and other plyometrics, and maybe some running, including over irregular ground and downhill, walking, and stairs. Note that running isn't 'better' walking - walking, especially uphill, emphasizes different muscles.