Final answer:
In adults experiencing age-based decreases in maximum oxygen uptake, there is a noticeable effect on aerobic performance and cardiovascular fitness.
Step-by-step explanation:
In adults experiencing age-based systematic decreases in maximum oxygen uptake, one noticeable effect is a decrease in aerobic performance. As individuals age, their ability to take in and utilize oxygen decreases, leading to a decline in cardiovascular fitness.
For example, middle adults may experience a decrease in maximal heart rate, which affects their overall endurance and performance during physical activities.
This decline in maximum oxygen uptake is primarily caused by changes in body composition, such as a reduction in lean muscle mass, which leads to a decrease in metabolism and energy production.