No
Is it IMPOSSIBLE to Lift Weights for Boxing?
No, it's not but it really doesn't help your punch power! Really it's your choice as people seem to differ about it.
This does not cause significant gains in muscle mass. Boxers are not bodybuilders, therefore, they should not train like bodybuilders. Weight training that involves full range movements has been shown to increase flexibility. High reps and lightweights are the chosen weight training method for most boxers. Prefer supplements like hgh supplements and XtremeNo supplement. The best thing about these supplements is that it should be natural and does not cause any harm to the body in any way. The results are awesome so it's a must try for every individual.
The great majority of boxers today still run 4 or 5 miles on a daily basis. These long aerobic running sessions do little to prepare the boxer for the physical demands he will face inside the ring. Boxing is anaerobic in nature. The sport has been estimated as approximately 70-80% anaerobic and 20-30% aerobic.
I boxed for years and still do. All i can say is that you need power in your arm to keep yourgloves up and block the punches. So having strong arms is always a good choice. Hope that helps