He praised Beard for establishing performance protocols and structures in Wales, which are helping to achieve a worldwide showcase of player fitness levels.
Beard leaves Wales before the Rugby World Cup in the knowledge that the four-strong national squad performance team in place, work to a plan, which has been refined and established across the past six years.
Warren Gatland said: ”I want to congratulate Adam on his new appointment and thank him for putting in place a performance plan which has placed our player fitness standards on a new level.
“The team he is part of now work to systems and structures which are precise, effective and challenging to all the players we select and monitor.
“Because the conditioning and nutrition team are working to a closely devised plan we can ensure that we look for the very best person to replace Adam.
“Our high performance team is incredibly strong and Adam has to take due credit for ensuring Wales is well placed for the future.
“While I am disappointed that Adam is leaving before the Rugby World Cup this is an opportunity that only comes around once in a lifetime and to attract this interest from the NFL shows how far our high performance reputation has grown in recent years.”
Adam Beard said: “I am looking forward to my new appointment and the challenges ahead but firstly I would like thank Warren, the players and everyone associated with the WRU for the last six years.
“While I’m disappointed to miss out on an exciting year ahead, I am confident we have put in place an excellent performance programme and have the team in place to deliver it.
“I think Wales has some of the best practitioners in the game and I have enjoyed working closely with them to provide a platform for our players to flourish on the international stage.
“The decision to go was undoubtedly made easier because of the strong team in place along with the outstanding facilities we now have in place here in Wales.
“We have been developing our high performance protocols for a number of years now and the plans for Rugby World Cup are already in place and I look forward to monitoring Wales’ progress closely.”
Under Beard’s tenure Wales have also installed state-of-the art fitness facilities at the WRU National Centre of Excellence with new cryotherapy and altitude chambers to enhance training protocols.
The physical performance department comprises of age grade, national academy, sevens, women’s and national squad performance teams, with the make-up of the senior national squad including Assistant Strength and Conditioning Coaches, Huw Bennett and John Ashby, Nutritionist Jon Williams and Sports Scientist Ryan Chambers.
For Rugby World Cup the national squad training schedules will be enhanced with training and conditioning tours to Poland, Qatar, Switzerland and North Wales.
The Group Chief Executive of the WRU, Roger Lewis added: “I want to thank Adam Beard for the tremendous dedication and skill he has brought to his role of Head of Physical Performance for the WRU.
“His skill and focus have helped ensure we now boast a strong and well deserved reputation for our all round player conditioning standards.
“It is credit to his hard work that a NFL franchise have noted our achievements and seek to replicate the work done here in Wales in the USA.
“Adam is a world class high performance director and I know Warren will want to ensure we recruit someone who can continue to take our standards forward with the strong team Adam has helped put in place.”
The Chairman of the WRU, Gareth Davies, said: “I want to congratulate Adam on his new appointment and thank him for the fantastic work he has done for professional rugby in Wales.
“We are now renowned for the standard of conditioning of our players and known for the innovative and scientific methods we employ to push those levels higher.
“I know our international players take the field fully confident they are in the right shape to compete at the very highest level of rugby.
“The structures Adam has put in place will now serve us well and whoever we appoint will be able to build on incredibly strong foundations.”
