Swimming without other exercise?

I'm surprised so many people say swimming made them gain weight.How could that be? Well, as one fast swimmer was widely quoted this spring as saying, some master’s swimmers swim too fast when they’re supposed to swim slow and too slow when they’re supposed to swim fast. Different people seem to take different meanings from that statement. As I understood it, especially when I reflected on my own training tendencies, some people are perhaps doing too much sprinting and too much work beyond their anaerobic or lactate thresholds, and perhaps not enough “basic endurance” work at the middle of their aerobic ranges. At the “basic endurance” levels, your “work” is mostly fueled by the burning of fat rather than the depletion of muscle glycogen. You might be reaching this “basic endurance” range if your pulse is above 120 and perhaps in the 140s, if you had a heart rate of about 150 or so when you attained your lactate threshold in a T-30 swim. If you swim at this level for extended periods and regularly, you improve your cardio-vascular conditioning, touch off a cascade of hormonal reactions that aid in healing as well as conditioning and strengthening – and you’ll burn plenty of fat. This is why even sprinters (especially master's swimmers, who need more time to recover than your average 15-year-old), also, should spend several days a week on this kind of aerobic training rather than trying, every day, to fully engage the fast-twitch muscle fibers and the anaerobic energy systems. Now, I’m hardly an expert, and I started master's swimming less than a year ago. My view is based on what I understood from this book: www.amazon.com/.../ref=pd_bbs_sr_1 Maglischo also touches on the question of whether non-swimming work is better. The answer, after weighing all of the evidence, is: nope.

I'm surprised so many people say swimming made them gain weight.How could that be? Well, as one fast swimmer was widely quoted this spring as saying, some master’s swimmers swim too fast when they’re supposed to swim slow and too slow when they’re supposed to swim fast. Different people seem to take different meanings from that statement. As I understood it, especially when I reflected on my own training tendencies, some people are perhaps doing too much sprinting and too much work beyond their anaerobic or lactate thresholds, and perhaps not enough “basic endurance” work at the middle of their aerobic ranges. At the “basic endurance” levels, your “work” is mostly fueled by the burning of fat rather than the depletion of muscle glycogen. You might be reaching this “basic endurance” range if your pulse is above 120 and perhaps in the 140s, if you had a heart rate of about 150 or so when you attained your lactate threshold in a T-30 swim. If you swim at this level for extended periods and regularly, you improve your cardio-vascular conditioning, touch off a cascade of hormonal reactions that aid in healing as well as conditioning and strengthening – and you’ll burn plenty of fat. This is why even sprinters (especially master's swimmers, who need more time to recover than your average 15-year-old), also, should spend several days a week on this kind of aerobic training rather than trying, every day, to fully engage the fast-twitch muscle fibers and the anaerobic energy systems. Now, I’m hardly an expert, and I started master's swimming less than a year ago. My view is based on what I understood from this book: www.amazon.com/.../ref=pd_bbs_sr_1 Maglischo also touches on the question of whether non-swimming work is better. The answer, after weighing all of the evidence, is: nope.