Robert Kraft isn’t certain he will fulfill his New Year’s resolution to run every day of 2015. At 64 years old, the Miami songwriter suffers from arthritis, spinal stenosis and a degenerated disk.

But there are 40 reasons to think he might succeed. Each Dec. 31 since 1974, Mr. Kraft has resolved to try running every day of the New Year, and he has yet to fail. After completing his run Wednesday, Mr. Kraft will have logged 40 consecutive years of daily running. That translates to 14,610 consecutive days of running, typically...