Thanks, Bill, for your appreciation. Like you, I have switched to a combination of isometric and dynamic training within the same repetition. With a weight that allows me to get to failure within 8-12 reps. I keep the tension after the last rep in a maximally extended position. I hold that as long as possible, typically 10 to 20 seconds. I notice that the effect on muscle growth is better than with conventional training. At the same time, I monitor my pulse wave velocity daily, to make sure I'm not doing anything counterproductive. Since, as men, we lose muscle mass once we are past 60 (which I am), I guess it will pay to to keep that loss at a minimum or, better still, prevent it altogether.