Does bending and lifting cause disc herniations?

Tom Jesson, in a fabulously detailed exploration of this perpetually unanswerable question:

“The idea that discs are eager little adapters is not true. … True, when you study discs cells in a lab, they do like load — but only moderate load at a moderate frequency. Anything more than that, they definitely do not like. … Injured or already-degenerating discs basically can’t adapt to exercise any more.”

But!

“Even if you are doing a lot of it, bending and lifting [with any technique] is unlikely to be the decisive factor. Whether or not you get a disc herniation is probably more determined by your luck (in terms of whether or not you suffer physical trauma), your general health, and your luck again (in terms of what genes you inherited from your parents).”