A too soft saddle usually becomes very uncomfortable after approx. 30 – 45 minutes on the bike.
The sit bones sink in so far, that sensitive soft tissue such as muscle and tendons are aggravated. After approx. 30 – 40 minutes a dull deep pressing pain sets in.
The sinking in of the sit bones also causes the perineal area in men and the lower positioned pubic bone arch in women to be subjected to higher pressure. Specifically soft padding will effectively stop the blood flow.
It is rare that the padding is so soft that the saddle shell causes the discomfort.