The Fastest Age

When I was in college I took a physiology course. In one lab we performed an EKG(?) (its been a long time) where we measured the electrical output of the heart. My heart was clearly different from the others in the class - in normal circumstances the signals would have indicated a heart too large because of some anomalous stress, and considered at very high risk for further damage and a heart attack. I can't remember the details, but we (the people in my lab group) could determine relative sizes (or at least muscle activity) of the various chambers of the heart. Instead, it was probably a consequence of my training, and not a problem at all, so I know that the heart responds to training by growing larger. I confirmed this at the time by a brief literature search. (as I recall, one paper was titled something like 'why endurance athletes have defective hearts.') What I don't know is if the heart remains large during 20 years of pretty minimal exercise, or if a heart will become larger more easily after restarting training than for someone who never trained as a youth. However, I think it likely that a large heart and the ability to pump more blood per beat is one reason why my resting pulse regularly goes below 50 beats/min, and is often in the low 40's when I wake up. This is after three years of swimming again. Even before I started again my resting pulse was about 60 - 65, which I think is in the low end of normal for sedentary people. It is very likely that increased pumping blood volume contributes to VO2 Max, but I do not think it is necessary or sufficient for a large value of VO2 Max.

When I was in college I took a physiology course. In one lab we performed an EKG(?) (its been a long time) where we measured the electrical output of the heart. My heart was clearly different from the others in the class - in normal circumstances the signals would have indicated a heart too large because of some anomalous stress, and considered at very high risk for further damage and a heart attack. I can't remember the details, but we (the people in my lab group) could determine relative sizes (or at least muscle activity) of the various chambers of the heart. Instead, it was probably a consequence of my training, and not a problem at all, so I know that the heart responds to training by growing larger. I confirmed this at the time by a brief literature search. (as I recall, one paper was titled something like 'why endurance athletes have defective hearts.') What I don't know is if the heart remains large during 20 years of pretty minimal exercise, or if a heart will become larger more easily after restarting training than for someone who never trained as a youth. However, I think it likely that a large heart and the ability to pump more blood per beat is one reason why my resting pulse regularly goes below 50 beats/min, and is often in the low 40's when I wake up. This is after three years of swimming again. Even before I started again my resting pulse was about 60 - 65, which I think is in the low end of normal for sedentary people. It is very likely that increased pumping blood volume contributes to VO2 Max, but I do not think it is necessary or sufficient for a large value of VO2 Max.