I constantly emphasize to my clients that they don’t merely want to get a resistance from point A to point B, they want to connect their mind to the targeted muscles and really FLEX them as they are going through the movement . I jokingly refer to them as becoming a “flexoligist”.
Here’s a simple example of what I mean. Stand or sit and let your arm hang naturally at your side. Now, with your palm up and your elbow fixed at your side, raise your hand toward your shoulder at a comfortable speed, pause, then lower it down. Again, have your hand and elbow as you just did but this time flex your biceps muscle as you are pulling your hand towards your shoulder, when you reach the top forcefully flex the bicep again and feel the contraction. Lower your arm down but again, flexing the bicep. You can feel now only the bicep tightening but the shoulder and the triceps muscle – especially as you lower your arm. Try using this method when you strength train and see if it doesn’t make a difference in the amount of resistance you use (you will use less weight but that isn’t a bad thing at all) but you will certainly feel and notice a difference in how your muscles respond.