Section 38. Boxing or sparring matches or exhibitions shall not exceed ten rounds in length, but if such matches or exhibitions are to determine championships, they may, in the discretion of the commission, exceed ten rounds in length but not fifteen. No round in any such match or exhibition shall exceed three minutes. No contestant in a professional match or exhibition shall participate in more than ten such rounds, or more than the number of rounds determined by the commission as aforesaid, as the case may be, during any period of seventy-two hours. No contestant in amateur boxing shall compete in more than two tournaments in any period of seven days, nor participate in more than three contests between twelve o’clock noon of any day and twelve thirty o’clock in the morning of the next day. All amateur boxing or sparring matches or exhibitions held on any day shall terminate at or before twelve thirty o’clock in the morning of the next day. The contestants in professional matches or exhibitions shall wear, during the contest, gloves weighing at least eight ounces each and in amateur matches or exhibitions, unless otherwise authorized by the commission, the contestants shall wear, during the contest, gloves weighing at least eight ounces each. Every boxer participating in a boxing or sparring match or exhibition shall be required to wear a standard protective device, to be approved by the commission.