The Core Resistance Toning Kit by Natural Fitness (Plant-a-Tree) is a high quality and eco-friendly group of exercise tools that can be used for a total body workout. The Resistance Toning Kit contains: A burst-resistant exercise ball made without toxic phthalates. A natural rubber, earth friendly and provides more resilience over the synthetic rubber, adjustable medium resistance tube set. These can be adjusted for limitless exercises. A natural rubber, eco-friendly and resilient, padded ankle cuff for versatile leg exercises. Also included is a workout DVD featuring fitness expert Andrea Metcalf who inspires and teaches. This DVD includes a Level 1 and Level 2 workout, complete with warm up and cool down exercises. The Resistance Toning Kit is everything you need to reach your fitness goals in one easy to use package. Resistance training is a form of strength training in which each effort is performed against a specific opposing force generated by the resistance created in stretching the resistance tube. It is called "isotonic" exercise when the body part is moving against the force, or stretching the tube. Holding that resistance against the force, the exercise becomes "isometric" exercise. Resistance exercise is used to develop the strength and size of skeletal muscles. Properly performed, resistance training can provide significant functional benefits and improvement in overall health and well-being. The goal of resistance training is to gradually and progressively overload the musculoskeletal system so it gets stronger. Research shows that regular resistance training will strengthen and tone muscles and it INCREASES BONE MASS! Resistance training is a real positive for those suffering from a lack of bone mass. It is made by Natural Fitness, an eco-friendly yoga and fitness company and that means dedication and quality products. Natural Fitness uses a solar powered web host which captures 100% of its electricity from photovoltaic panels located on its roof. They also use all recycled packaging,and solar power for their offices and manufacturing plant. Natural Fitness also Plants-a-Tree in the rain forest for each of their products we sell! Planting a tree helps offset the environmental impact from manufacturing and transportation of your purchase. The trees are planted in areas of the rain forest that have degraded soils from slash and burn farming, clear-cutting and over use. Trees help stabilize erosion while rebuilding the soil and protecting nearby streams and rivers. These trees absorb CO2 and other greenhouse gasses. Trees also release vital oxygen for decades while they provide important sustainable resources to the local communities such as food, fiber, fuel and building materials.