There are days when your mind and body cooperate, and you fall asleep instantly. There are also those dreaded moments when all you do is toss and turn and pray that sleep will come. Well, there is a trick to falling asleep in under 120 seconds, and it involves body relaxation.

According to the book "Relax and Win: Championship Performance," it takes practice to achieve instant sleep with this simple trick. In six weeks, one should be able to fall asleep instantly when these steps are followed accordingly.

The 1981 self-help book unearthed by Joe.co.uk cites this as an old method used by the American military. It is a four-step method that guarantees success. The first step involves relaxing the muscles in the face, in the tongue, jaw, and those around the eyes. The second step requires the shoulders be dropped to its lowest, followed by relaxing the upper and lower arm on one side and then the other side.

The third step is a breathing exercise: simple breathing out and relaxation of the chest. The fourth and final step calls for the legs, thighs, and calves to be relaxed.

Of course, this method does not come without a visual image that promotes sleep. According to the book, when lying there, one can visualize any of these three mental images to lull themselves to sleep. One is that of lying in a canoe on a calm lake, surrounded with nothing but the blue sky above.

The second image is that of being snuggled in a black velvet hammock in a pitch-black room, while the third is a mantra of sorts. While lying there, one should say "don't think" over and over for ten seconds.

This method to fall asleep in less than two minutes was advice given to sports enthusiasts. It was meant to help them release tension before a competition and help them "improve sports performance and reduce injuries" through relaxation.

While this process does not guarantee instant success, it does improve sleeping patterns. According to the book, this method worked for 96 percent of people who committed to it for six weeks. However, for the 4 percent who found no benefit from this practice, then the U.S. Army suggests finding ways that work for you.

"The bottom line when it comes to getting restful sleep is doing what works for you. There is no magical formula other than listening to your body."