The campaign involves participants doing 22 pushups — or however many they can — for 22 days. They must then post a video on social media and tag others to continue the challenge. The videos are uploaded with the hashtags #22KILL and the number of pushups completed.

The 22 Pushup Challenge was launched by the veteran empowerment foundation Honor Courage Commitment. The organization’s 22Kill movement aims to raise awareness about post-traumatic stress disorder and other mental health challenges veterans face, along with building a community of support for them.

The campaign has even received support from celebrities. Actors like Dwayne Johnson and Chris Pratt have posted videos of their pushups on Instagram, Facebook and Twitter. The ultimate goal of the project is to reach 22 million pushups worldwide. The organization keeps a live tally using participants’ hashtags.

The challenge represents the fact that an average of 22 veterans commit suicide each day. The commonly cited figure is derived from the Department of Veteran Affairs’ (VA) 2012 Suicide Data Report. The VA recently adjusted the number down to 20 veterans a day who take their own lives.

Although the number may have changed, the mission remains the same. The key message of the 22 Pushup Challenge is that public support can help veterans deal with the difficulties they may face when trying to reintegrate into civilian life after deployment.