The end of a professional athlete’s career rarely follows the neat, upward trajectory most careers do. While others might peak in their 50s or 60s, athletes often face a sharp pivot in their early 30s, their physical prime behind them. Suddenly, they are earning less, and are much less in demand. Few have amassed the riches to retire or have the profile to retreat to the after-dinner speaking circuit or the television studio.   Niall Woods, who played rugby for Leinster, London Irish, and Ireland, has lived through this shift twice — once as an athlete and later as an advisor,…