Walking is not the most exciting form of exercise a person can take on for fitness. Yet it is low impact and requires no fancy equipment. That makes walking a simple activity for those new to exercise. Walking is less likely than other exercises to cause injury to leg tendons and muscles. All it requires is a good pair of sneakers—no cables, stylish outfits, or weights required. Of course, a person could increase the benefit of a workout by adding weights or speed walking. Explain whether the main idea is explicit or implicit in this paragraph.

It is explicit because it is directly stated in the paragraph.
It is explicit because it is not directly stated in the paragraph.
It is implicit because it is directly stated in the paragraph.
It is implicit because it is not directly stated in the paragraph.