Isn't this type of riding, going over and above your LT and possibly blowing up, more harmful than in terms of long term development?

I'm just curious as last saturday I went a bit overboard and spent about 45 mins of a 3hour + ride over my LT. I blew up during the first part but after the break felt better.

The next day's ride was even longer and more challenging (lots more climbing) but I just kept it below LT and did quite well despte being tired from the day before.

Thoughts?