What Raises Testosterone Levels?

Originally published: Aug 1, 2025

Updated occasionally 

Advent of sunscreen---lack of sun exposure (also less outdoor work) (large 100% (?) increase)

Obesity (20 to 50% effect size (?))

Weight training (20 to 30% higher free testosterone(?)) 

Age (-1% per year after age 30 (higher if overweight))

Cardio (Long slow cardio not good compared to HIIT) 

Insulin resistance

Supplementing zinc (if deficient) 

Limit porn masturbation 

Estrogen miminics

Heavy drinking decreases testosterone 

Smoking--- small 11% (?) increase  

Dominance behaviours

Being around a naturally cycling female

Cold exposure

Sleep (could be a big factor ?)