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Sheldon S. Zinberg, MD, Founder

Nifty after Fifty® is passionate about senior health, and that passion started with its Founder, Sheldon S. Zinberg, M.D. Dr. Zinberg knew that physically active seniors had better long-term health than sedentary ones, so he developed a fitness center that not only catered to the 50- to 95-year-old market, but was revolutionary in its approach and unique in its goals.


In 2006, he opened the first Nifty after Fifty in Whittier, California.  In order to bring good health to more seniors, Nifty after Fifty partnered with senior health insurance companies to provide their members with the benefit of Nifty’s unique programs.

Sheldon Zinberg, M.D., served as a Clinical Professor for both the University of California at Irvine and The Western University of Health Sciences. He established CareMore Medical Group in 1993 which improved the delivery of healthcare services to over 100,000 members. In 2006, Dr. Zinberg founded Nifty after Fifty® and later Encore Wellness®, a population health management company centered on sustainable clinical programs with predictive modeling and data analytics.

Dr. Zinberg graduated from Seton Hall University and attended the Philadelphia College of Osteopathy with honors. In 1962, he obtained his M.D. from the University of California, Irvine. He was the recipient of multiple awards including the Cooper Alloy Scholarship for academic achievement and was invited to the White House to provide guidance to the Department of Health and Human Services. He was an active speaker and successfully published two books, "Win in the Second Half" and "Nifty after Fifty - A Guide to Better Aging & Fitness for Men and Women."

Michael Merino, President & CEO

Michael Merino has over 25 years of experience in the senior healthcare arena.  He is a nationally recognized consultant speaking on a variety of subjects including developing partnerships across the United States.  He served as President and CEO of Sterling Healthcare Management, as CEO of Southern Indian Health Counsel, and was the Senior Vice President and COO of CareMore Medical Enterprises. 


Throughout his career, Mr. Merino has been intricately involved in healthcare operations for mature adults. He has been involved in the formation of physician/hospital organizations in Hawaii, California, North Carolina, South Carolina, and Kentucky; and speaking to physician and hospital organizations on various subjects including developing partnerships across the United States.  He held the position of CEO for a healthcare consortium for Native Americans in San Diego, California.  Mr. Merino also played a large role during the formation of CareMore, a leader in health care.  In 2004, he returned to CareMore where he assumed the position of Senior Vice President and COO and was instrumental in the sale of that entity to JP Morgan Partners.

Rod Sled, COO

Rod Sled has over 20 years of experience in the fitness industry with 10 years dedicated to medical wellness operations.  After five years of honorable service in the United States Marine Corps, Rod started his career in fitness with aspirations of providing a better quality of life to the public through wellness programming.


During Rod’s tenure with 24 Hour Fitness, he rose quickly to District Manager.  Rod’s ability to encourage fitness participation yielded him national recognition for top performance.  Rod demonstrated a track record of opening multiple new fitness locations with record-breaking financial success.


In 2009, Rod joined Encore Wellness as Director of Operations with the task of launching six locations in a new market.  Rod brought his in-depth retail fitness experience to Encore Wellness and was instrumental in enhancing our culture of member engagement, customer service, and team productivity to the new market.  In 2012 Rod then launched six centers in two additional new markets with the same success.


With a track record of efficiently launching and managing multiple new markets for Encore Wellness, Rod quickly assumed additional responsibility for three existing markets.  Rod leveraged his experience in change management, team building, and passion for senior wellness to propel the existing markets to newfound success.


In 2019, Rod assumed the position of COO where he currently provides senior leadership for all markets.  As COO, Rod has profoundly impacted the organization and positioned it for future growth and expansion.

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