The phrase "a private exercise" is correct and usable in written English.
It can be used to refer to an activity or practice that is conducted in a personal or confidential manner, often for self-improvement or personal reflection.
Example: "Meditation can be a private exercise that helps individuals connect with their inner thoughts and feelings."
Alternatives: "a personal activity" or "a confidential practice".
Lan Tuazon prints her own currency, and requires a written promise from its recipients to distribute it further, thus turning art into a private exercise in growth capital.
At Shibden Hall Browne had begun his parallel career as a writer with Religio Medici, a journal largely about the mysteries of God, nature, and man, which he himself described as "a private exercise directed to myself".
So if meaning is to be obtained for the "sign", this must be achieved through a private exercise of ostensive definition, where I concentrate on the sensation and produce the sign at the same time.
This is a private exercise, and you don't have to, and probably shouldn't, show it to anyone.
He may exhibit them one day, he says, but painting has always been "a largely private exercise" for him, as opposed to illustration, which pays the bills.
An unfussy, nylon-string version of And I Love Her is one of the standouts of a typically subtle (though occasionally rather distantly private) exercise in guitar lyricism.
When entering into a private sale, exercise due diligence in obtaining a clear title, free of liens or tax liabilities.
The experts worked in a range of settings including NHS acute and community services, private exercise training providers, social care, academic institutions and The Care Inspectorate, Scotland.
The book that made him famous was one he wrote with no particular goal of publication, "for my private exercise and satisfaction".
In the abstract, this thought did not contradict the principles of the Great Separation, which gave reasons for protecting the private exercise of religion.
Although Cromwell made his detestation of Catholicism very plain, Catholics benefited from the repeal of the laws requiring attendance at parish churches, and they were less persecuted for the private exercise of their own faith than at any other time in the century.
