I was listening the other day to a podcast on cycling training. The trainer was talking about off-the-bike exercises that improve on-the-bike climbing ability.
He said something that struck me: He was talking about goblet squats (demonstrated correctly in the video above), and said that you should keep your knees in when doing them, to mimic your position on the bike.
This is often called the Specificity Principle: the exercise should mimic the target activity as closely as possible.
But superficially immitating the motion of riding a bike is naive:
A cyclist's knee is never flexed beyond 90 degrees, so if specificity is considered only in terms of knee flexion, the conclusion would be that squatting above parallel is specific to cycling performance, and that full squats are not. This, in fact, is what many coaches and trainers believe and advise their athletes to do, in more sports than cycling. This is misguided. The problem here is a misunderstanding of the exercise and its relationship to the sport skill: a partial squat does not produce a strong hamstring contraction. Any cyclist who does partial squats is not developing balanced strength around the knee and is neglecting the muscles used in the hip-extension aspect of a properly executed pedaling cycle. [...] So although the partial squat may superficially look more specific, in anatomical action and in the quality of muscular function and development the more generalized full squat is more applicable to the activity. The addition of leg curls to the program is not the answer; correct analysis of the squat is.- Rippetoe & Kilgore
"Sport-specific" training means targeting the most applicable muscular and metabolic aptitudes. It means giving stability, lateral movement, or plyometrics more or less emphasis. It does not mean doing weird half-movements or pretending you're on your bike when you're not. If you're riding regularly, you're getting plenty of "sport-specific movement."
Want a squat variant that's more cycling-specific? How about a Bulgarian split squat? Full range of motion, similar angle, and some instability. The trade-offs here: the instability limits pure strength gains.