The short answer is no – they are not. But I highly recommend them because they help a ton. A while ago I purchased some rash guards for no-gi classes at my dojo, and the difference is night and day in terms of comfort when rolling. There are two main reasons for this:

First, it helps reduce the number of bruises on the arms, even when worn under a gi. Many bruises I get are from pinches when someone is grabbing at my arms when wearing a gi. A rash guard can help reduce the occurrences of these types of bruises.

Second, it really does do what the title of the product says it does – reduce rashes. I notice rashes more when rolling no-gi, usually when the opponent’s skin or garments rubs against my skin. I’ve also experienced rashes from rubbing against the mat. A rash guard helps reduce this.

Some people may be hesitant to try rash guards because they seem to be primarily targeted for people who are extremely “ripped”. Look at this picture of Hayabusa’s rash guard, for example:

Most people don’t look like this. Even in Jiu Jitsu.

If you are hesitant to try rash guards because you don’t look like Arnold from the first two Terminator movies, I’d still encourage you try one because no one is going to be judging how you look – at any dojo, everyone is there to train. If you are still hesitant you could always wear a tee-shirt your rash guard.

If you decide to purchase a rash guard online remember to be aware of the online seller’s return policy. Sometimes they are less flexible with rash guards, which can be sort of annoying. I’m actually planning a blog post for on the topic in the future.

pic credit(s): mmawarehouse.com (per their terms and conditions) at http://www.mmawarehouse.com/Hayabusa-Haburi-Longsleeve-Rashguard-p/hay-1002.htm. Its original image URI is http://www.mmawarehouse.com/v/vspfiles/photos/hay-1002-2T.jpg.