Question: Is it better to strength train with free weights or on machines?
Answer: Both free weights and machines have their positives. For a small population of people, machines are very useful. Maybe it's a population of untrained individuals who are just getting into resistance training or even a population of individuals who are coming off a rehabilitation. So machines have a place.
However, as quickly as possible it's important to get athletes into free weight kind of movements, because in free weights we have to overcome gravity and that's what we do in athletics, we overcome gravity. So getting them into free-weight exercises is going to be best for their skeletal muscles, for their connective tissue, for their bone adaptation and as well as athletic performance.
All the things that we do in athletics are to overcome gravity, and so training in a state where we are overcoming gravity with resistance is going to be very important for that individual to improve their athletic ability.