I am wondering about the ideal frequency of strength and core training exercise.
I mainly want to focus on quadriceps / knees / hips.
As I am time crunched, is it ideal to do strength training 6 times a week for only 15 minutes each time, or is it better to train 3 times a week for a 30 minute period ?
Or should I train at least 1 hour per workout in order to benefit from strength training ?