SLEEP LATE AND HAVE POOR SLEEP (-15% = 85% Testosterone): University of Chicago ran a protocol on 28 men where a decrease to 5 hours of sleep for a week saw a 15% decrease in testosterone
EAT HIGH-FAT AND SUGAR FOOD e.g. McDonald's, Junk Food etc (-25% Testosterone = 60%): Eating a high-fat fast-food meal can reduce testosterone levels by 25% within an hour of ingestion in overweight and obese men, Australian research shows.8
DON'T SPRINT (-26% Testosterone = 34%): Sprinting regularly shows that you'll increase your testosterone, libido, work ethic and overall health.