N Why do exercise needs vary between individuals?
Because you do not want to strain any muscles or tendons. It takes steps to get to
the top
I

Exercise needs vary on individuals for many reasons. First of all, it could be physical problems like weight. If a person is to heavy, or to small. Then starting out exercise slow is best. Often times over exercising for obese people, or people who are to thin, can cause blackouts, a loss of water retention, and exhaustion.
Another could be health issues. People with certain health issue may find it hard to work out, and need help with finding what works best for them.

Awould be the answer

It is less likely that the shoe will slip while someone is walking