Does exercise help with curing asthma?

No. Exercise will increase your endurance, fitness, general health & by doing regular exercise will increae your respiratory & general immune system. Asthma requires medications. Avoid exercise if there is an asthma attack.
Asthma. There is not a cure for asthma however there are some people who have asthma that can be asymptomatic. This subset of asthmatics do not require medications at all during periods when the asthma is not symptomatic.