A 51-year-old personal trainer shares his 20-minute workout to build an maintain muscle
Harley Pasternak, whose clients have included Kim Kardashian, Rihanna, and Robert Pattinson, does resistance training to build and keep muscle mass as he ages.
Harley Pasternak, whose clients have included Kim Kardashian, Rihanna, and Robert Pattinson, does resistance training to build and keep muscle mass as he ages.
This article was originally published at: https://www.businessinsider.com/personal-trainer-shares-2...