As the years pass, muscle mass in the body generally shrinks, and strength and power decline. Sarcopenia—defined as age-related muscle loss—can begin at around age 35 and occurs at a rate of 1-2 percent a year for the typical person. Studies suggest that strength and power training can help reverse these effects and restore muscle function. [health.harvard.edu]
Hold onto pullup bars or fitness rings using your fingers. This will help build better grip strength and will help prevent calluses from your palm slipping down the bar. [stronglifts.com]