There's nothing wrong with being winded during warm-up. I often do 2-3 hours of tennis without problems, but the first 15-20 minutes is the most difficult. Just keep it up and eat right.
I agree with this. The first 15-20 minutes when the body is getting warmed up and the heart is getting up to speed you can often feel knackered, then as you carry on and your body gets used to working at that higher rate you ease into it. Sounds like you're doing a great job getting the weight down!
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