Machines are built with a specific path, one that wasn’t designed for you. If you’re too tall, too short or your arms or legs aren’t the same length, that fixed path won’t match your physiology which is potentially going to increase the risk of injury. As a Personal Trainer, free weight training is what I integrate into every program as it is massively effective for all different types of goal such as running or weight loss. The squat compared to the leg press demands more from you to keep your form correct while the leg press is only focusing on your legs. Adding free weights like a barbell or dumbbells is only going to ask more from your upper body making it a full body exercise which is more beneficial to you.