Final answer:
During maximal exercise, breathing rate typically increases more significantly compared to tidal volume, although both increase to meet the body's oxygen demands.
Step-by-step explanation:
When ventilation increases during maximal exercise, breathing rate and tidal volume both typically increase to meet the body's increased oxygen demand. However, breathing rate (BR) tends to have a more pronounced increase compared to tidal volume initially, as the body can more rapidly adjust the rate of breathing. As exercise continues and becomes more intense, tidal volume also increases substantially, but there is a physiological limit to how much tidal volume can increase. Therefore, while both breathing rate and tidal volume increase, the rise in breathing rate is usually more immediate and significant.