Circuit training is a great way to train your body. When doing this type of training, it is very important to stay to an exact schedule. The amount of time to rest between sets isn’t some arbitrary number, rather, it is an integral part of your workout.
The GymBoss is an interval timer that serves this exact purpose. It has been shown that a person who works out with an interval timer will experience better gains over a period of time. The reason seems to be psychological as you always have something pushing you to keep going.
By clipping it to your belt, you can program the timer to give a slight vibration when it is time to start the next set. For those that are into serious training, it might be a good idea to give a product like this a look.
Check them out at their site, www.gymboss.com.