Yes it can, however; doing this exercise for a long period of time can have little or no effect as your body will get used to the strain you are putting it under. Try 20 minutes with another type of exercise for a couple of days then 30 minutes plus a DIFFERENT exercise. Up your minutes every 3 days or so so your body does not adapt to just one certain movement.
Let's say you enjoy swimming. One day you decide to swim alone. But it's a risky idea because you could drown and no one would be there to help you in time. So it's best to have others around incase you have an accident or need help.
