This phrase can commonly be heard during the
instructions given by a
referee at the beginning of a
Boxing match. In many ways though, this can be seen as the ultimate rule of modern Boxing.
The most basic interpretation of this phrase is that during the fight the boxers involved should always try to prevent themselves from getting punched. In particular, they should not put their hands down just because the referee is standing in between them and their opponent or because the bell to end the round just rang. Boxing is an intense sport and punches on the break or late punches sometimes get illegally thrown. Getting hit with one of these will most likely not DQ the thrower. They may have a point deducted. The person taking the blow will have to recover from it and continue on. The super-majority of the time things like this are accidents. Of course, sometimes, it's the act of a desperate, dirty fighter. In this sense, "Protect Yourselves at All Times" is something of a warning, or advice.
In another sense, the phrase becomes a rule that the fighters must follow or the fight will be stopped. One application of this is when a fighter has sustained enough punishment to become unconscious for 10 seconds. At this point they have no ability to defend themselves and the fight must be stopped. Similarly, a fight will be stopped if a fighter's opponent seems to be landing big punches at will. If the fighter being pummelled doesn't show some ability to stop the onslaught the fight will be stopped, and quickly. If a good referee is involved and one fighter simply shows no ability or knowledge of how to properly box but their opponent does the fight will be stopped before someone gets hurt. If you can't demonstrate your ability to defend yourself in Boxing you will quickly be taken out of the fight.
Boxing is commonly thought of as a "brutal" sport. But when this rule is applied correctly Boxing involves very little injury or danger to the fighters, even in the long term. Unfortunately, there is one last application of this rule that isn't enforced enough. A fighter needs to be able to prove that they can defend themselves from serious injury before they ever get into the ring. And someone needs to consider if they can properly defend themselves against their opponent. This applies to "Boxers" who have never had real training that somehow get into the ring. It also applies to Boxers who have been fighting for a long time. Many people like to use Muhammad Ali as an example of why Boxing should be outlawed. It wasn't the memorable battles Ali fought against George Foreman and Joe Frazier that brought on Parkinson's Disease. It was the fights late in his career against Leon Spinks, Larry Holmes and Trevor Berbick that damaged him. When you've taken sustained damage in your Boxing career and your physical abilities start to decline you no longer have the ability to defend yourself against this sort of trauma. Sadly, this still goes on today. My generation's "Muhammad Ali" may very well be Evander Holyfield, who is still fighting. Holyfield has already shown signs of physical deterioration, but is scheduled to fight the big, heavy punching Hasim Rahman on June 1, 2002. Hopefully he'll lose a decision to Rahman without taking too much damage and decide to retire again.