Those are not necessarily examples of lifting. Those could as well be explained by the contribution of not pressing on the opposite pedal (to keep the foot from sliding).
And not pressing doesn't shine any light on the force of lifting.
And not pressing doesn't shine any light on the force of lifting.
The foot doesn’t slide with clipless peddles. The foot is locked in position. And you can absolutely use lifting and pushing combined - I have done this many times on long sportives (~100 miles); it can give respite to the ‘pushing’ muscles
So you obviously have never used clip in bike pedals before. Why are you trying to argue this point if you know nothing about what you're talking about?
Preventing sliding by pushing is how effort is wasted and is a possible explanation why a cyclist might feel much stronger when clipped in and no longer has to push - while attributing the lower effort to the upstroke pull.
They are, and this is trivially demonstrable by literally just trying it on a bike. Seriously. Go put a road bike in the highest gear and try to get up to speed from a standstill. Not only will you be pulling up on the rear pedal, but you’ll be using your arms to try and wrench the handlebars off the stem too.
Go climb a steep hill. Same thing occurs. It’s not like this is subtle. The contribution of your rear leg very clearly contracting will be impossible to miss.