i think you are having a normal response...take rest between sets to recover and reoxygenate.
are you holding your breath to stabilize abdominally during the movement?
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A man of sense is never discouraged by difficulties; he redoubles his industry and his diligence, he perseveres and infallibly prevails at last.
what is the right format should we hold breath or not. For all lifting i make sure I breah out while lifting and breath in when down. should i change this or is it okay.
For squats most take a deep breath before squatting and push out on their belt from their belly, squat down and once you get past the sticking point of your squat you can breathe out.