Even for 20 year old elite athletes, research says doing a combination of long, low impact work plus a few hard session gives best results. Too much hard work doesn't help, it hurts. This isn't age getting you, it's a bad training plan.jvander76 wrote: ↑June 18th, 2022, 10:17 amThanks Glen. Perhaps I need to do fewer strenuous workouts. At least for now. It really isn't in my nature, even at 67. I probably need to take a longer view and build my endurance more. I can go back to trying for PB's later. As I said, I'm on a learning curve. I tend to not use age as an excuse, but I suppose there is no point in denying that it has an effect.
Garmin sport watches caused a fuss when they started reporting hard workouts as "Unproductive: your training load is at a good level, but your fitness is decreasing. Your body may be struggling to recover, so you should pay attention to your overall health including stress, nutrition, and rest." What they meant is the user got enough hours of exercise, but did too many hard workouts with too little recovery time between workouts. People got upset "I worked really hard, it had to help". Nope, it didn't.
Net is do most of your work each week at a pace where you can talk conversationally, and also do 1 or 2 hard workouts. Here's a ted talk with an overview, post if you want more details. https://www.ted.com/talks/stephen_seile ... e_athletes