The phrase 'avid practitioner' is correct and usable in written English.
You can use it to describe someone who is enthusiastic or devoted to a particular activity or skill. For example, you could say, "Mary is an avid practitioner of yoga, regularly attending two classes per week."
He was an avid practitioner of the fireman's carry.
The president has long been an avid practitioner of personal diplomacy, and here in Lima he seems almost sorry to break off some of his relationships.
He's an avid practitioner of tai chi.
Steven Jefferies is a second year law student, and avid practitioner of Brazilian Jiu Jitsu.
Madonna reportedly is an avid practitioner of Ashtanga yoga, (surprise!) a particularly strenuous form.
At the time I'd been an avid practitioner of Transcendental Meditation and one of its stated goals was that it could help to flatten the emotional highs and lows that we normally experience.
Even avid practitioners of the new, though, feel a tug toward the old.
It has become a key plank of multinational tax strategies.Technology companies, with oodles of IP to shift around, are avid practitioners of the art.
It was also a statement to the gay community, which Opie saw as chasing respectability at the expense of sexual radicals like her and her friends, who were avid practitioners of sadomasochism.
To understand how statecraft by Twitter works, I spoke to three avid practitioners, who are spread across the globe and work at different levels of government: Carl Bildt, the foreign minister of Sweden; Michael A. McFaul, the U.S. ambassador to Russia; and Naheed Nenshi, the mayor of Calgary, Alberta.
The state-run Xinhua News Agency asserted that the self-immolators were "avid practitioners" of Falun Gong who had taken up the practice between 1994 and 1997, and that they fantasised during the preceding week about "how wonderful it would be to enter heaven".
