The Proworks Resistance Bands work on a simple resistance principle & can be incorporated into your routine to add upper & lower body strength & flexibility. You can include the bands in a range of exercises & classes such as Cross Fit, Yoga & Pilates. Each resistance band offers a different level of resistance making it possible to work muscles throughout the whole body. The pack contains 4 resistance bands, all with different strengths: Pink: Light Yellow: Medium Blue: Heavy Black: Extra Heavy The Proworks Resistance bands are adaptable & suitable for multiple fitness levels & can also be used to aid recovery from muscular injuries. If this is your first time using resistance bands, don’t worry. The Proworks Resistance Bands come with a free workout & safety guide. The Resistance Bands & workout guide fit neatly into the carry bag provided, making them great to use at home, in the gym, when travelling or as part of an exercise class!