To hopefully improve I have done various exercises and tests myself including six minute walk test, climbing stairs and 3 minute step test which is the only one paced.
So the question is do you do the 6mwt at your fastest pace, brisk, speed walk or what? As it makes a difference to my sp02 readings.
Same for stairs walk up fast or leisurely?
Same for exercise really, I kept pulse meter on last night for first time during my walk and if I kept sp02 to 95 I didn't feel like I was pushing myself as I slowed down to keep within 95 compared to when I walk without a meter and had no idea what sp02 was... would I get any benefit walking faster even though sp02 would drop