Then he should not fight. Knees are a main connecting chain in movement and hitting in all fight sports. If your knee is bad, just do not fight.
That is relaxation and adrenaline. In a fight you are even more nervous and stiff and adrenaline kicks in. You need experience in real fights as well and get used to it. Fight and sparring conditioning loss happens due to lack of experience. Once you get comfortable and your technique starts kicking it is not that taxing. To be honest the most brutal and challenging cardio I had was while wrestling. Pushing and pull and wrestling with someone that uses opossing force is freaking draining. It is like doing 5 mins of almost max squats or deadliftsā¦
Maybe not. The main issue is to avoid what aggravates it, if boxing doesnāt but running does then I donāt really see an argument for not boxing.
Im gonna say if he has pain from running that is unique to running
see a dr.
work on your hamstrings - your mobility
If its bad enough that you cant run 5k - dont train either.
til you see a Dr.
If you are having a problem with running 5k in under 25 minutes you shouldnāt be competing - no one wants to hear that.
No one also wants to admit discomfort in training.