The validity of a sample size has nothing to do with the size of the set it's drawn from. 136 is a reasonable sample size, 25 is considered the minimum for a yes/no question.
This is why so many studies are impossible to replicate.
The sample size has everything to do with the hypothesis here. There is no one size fits all meaningful sample size.
When you make a claim about "men" writ large you need enough data to establish significance and account for the multitude of other variables at play which are massive here.
