The description is of a certain spiritual exercise familiar to mystics.

There were certain exercises he could do later on.

Programme rewards for doing certain exercises or sports each week.

As it begins to catch on, certain particularly strenuous musical exercises may fall into disuse.

There are a few crucial moments in certain exercises when the man is instructed to stop moving.

Depending on your medical condition, certain exercises may not be recommended.

There are certain exercises and activities that can be harmful if performed during pregnancy.

In fact, there are many conditions for which certain exercises are positively beneficial.

They are also studying the effectiveness of certain exercises as a treatment option.

There are certain exercises you should do for the same purpose.