This document outlines 8 ways to naturally increase testosterone levels, including weight lifting, avoiding excessive calorie restriction, managing stress, taking vitamin D and zinc supplements, getting quality sleep, using herbal supplements, reducing exposure to chemicals, and adopting an overall healthy lifestyle through diet and exercise. Weight lifting and high-intensity interval training are highlighted as the most effective forms of exercise, while vitamin D and zinc have the strongest evidence as testosterone boosting nutrients. Managing stress, getting enough sleep, and avoiding excess chemicals are also recommended for maintaining healthy testosterone levels and long-term health optimization.