How to prevent a hernia while lifting weights?

Don't strain!: Lots of weight lifters develop hernias. Some they were born with and are brought out by the increased abd. Pressure lifting. Others get them from chronic straining. A weightlifer's belt may help in some cases. At any rate, the hernia should be fixed before you go on lifting or the hernia will enlarge and make repair more difficult and recurrence more common. You should not lift for six weeks.

You can't.: Hernias are caused by a variety of genetic and environmental factors. There are many weight lifters without hernias, many sedentary folks with hernias, so there's really no reliable way to know or prevent a hernia from developing.