I'm 63 yo. Go to gym 4 to 5x/wk. I've listened to the 1st of the 6 and now on 2nd podcast series w. Dr. Andy Galpin. I want to be efficient at the gym (not a warrior or heavy lifter; I've had lumbar fusion). I got a little confused listening as there's a lot of content (great content). Question: Long Duration/Steady State can be 30 minutes at submax work without any breaks - IS THERE A TARGET HR ASSOCIATED WITH THIS OR IS IT JUST A PLACE WHERE YOU WOULDN'T BE ABLE TO HOLD A CONVERSATION? I walk on a treadmill for 40 minutes at incline of 15 and speed 3 (I realize treadmills vary). I also use the stair machine. (I've been using a "fat burning" protocol - and now I know that's sort of a myth, but either way that's what I've been doing). DID I UNDERSTAND THAT I CAN ALSO WORK INTO AN ANAEROBIC PROTOCOL AS AN EXTENSION OF THE 30 MINUTE AEROBIC - example after 30 minutes on stair machine at steady state, work into an interval program, at 30 - 45 sec (or 120 sec) to get to max HR, then go down to a very low level for 5 minutes or so, and repeat. IF THAT IS A GOOD PROTOCOL, HOW MANY TIMES FOR THE INTERVALS - DID I UNDERSTAND CORRECTLY THAT ONE IS FINE OR IS THERE AN OPTIMAL NUMBER? ALSO HOW MANY TIMES PER WEEK? I got confused by that on the podcast. AND LASTLY: THE MAX AEROBIC CAPACITY: 8 TO 15 MINUTES HOLDING MAX HR? IS THAT THE RIGHT IDEA? AND IF SO, HOW MANY TIMES PER WEEK. my apologies in advance if my questions are wordy and confusing. I just want to get this part clear and efficient as I also do muscle strength training - my weakest protocol as I'm all over the place and those questions will come after I listen to more of the podcast series. I appreciate your taking the time to read this.