Originally Posted by
TMonk
It will also increase your sprint power by 50-100%
It will generally help interval power, almost anything a couple hours or less. For the typical USA races it is generally beneficial.
General to the OP and on weights.
The kids that lifted improved a bunch (vs other kids) reducing time on bike and increasing time in gym.
Two went from Cat 4 to Cat 1 in about 3 years. The other kids, mostly didn't, or it took longer. They had the advantage of being kids, but it was interesting to compare. Same trainer trained '84 Gold Indi Pursuit Olympian with weights.
USACycling coaches don't like that so much as they are trying to build multi-day endurance stage athletes and they tend to value road miles vs gym time.
If you do USA type races, likely trading in road time for gym time will make you faster. Good to have a program and trainer.
You only need to look at what trainer Chris Dellasega is doing with those like Ashton Lambie to see weights work - for specific disciplines.
There is the increased body mass issue. If you want to be a road racer, hill climber, I still think it is beneficial, but the ratio is different. You might do 2-3 hours weights for 20 hours road.
Chris pretty much told my kid he needed to ride a fraction of road time to get more power. Chris put him on ~ 4 hours weights for 1 hour road.
Junior bailed on that program as he prefers riding and is not looking for a job cycling, but the gains were significant.
Kids likes riding so bailed on that program, but the power was huge. That is one, and a few more above data points.