Squatting is an everyday activity and a necessary exercise for athletes of all levels. It is a versatile exercise to develop lower-body and core strength, as well as increase muscle mass and power. Jumping, or plyometrics, can also build power in the legs for a higher vertical jump, faster sprint and quick acceleration. Two different studies, one in the January 2010 "Journal of Strength and Conditioning Research," and the other in the June 2004 "British Journal of Sports Medicine" showed that having strong, powerful legs directly relates to sprinting and jumping performance.
A squat or jumping exercise works numerous muscles in the lower body, core, and even the upper body. The major muscles used are the quadriceps, the hamstrings, the gluteals, the lower back and the abdominals. The quadriceps are located in the front of the thigh, which consist of the rectus femoris, vastus lateralis, vastus medialis and vastus intermedius. The hamstrings are located in the back of the thigh, which consist of the biceps femoris, semimembranosus and semitendonosus. The gluteals are made up of the gluteus maximus, the gluteus minimus and the gluteus medius. The lower back has multiple small muscles called spinal erectors. The abdominals are made of three muscles, the rectus abdominis, obliques and transverse abdominis. When adding a bar or dumbbells on your shoulders during a squat, the lats, located on the back of the upper body, and shoulders, are also used. Jumping exercises use the calf muscles, called the gastrocnemius and soleus, in addition to the other leg muscles.
Squatting exercises can be done with both legs or with one leg at a time. Choosing different equipment -- barbells, dumbbells, weighted vests, bands or body weight -- when doing squats or jumps will work the muscles differently. By placing a barbell on the front of the shoulders, as a front squat, the quadriceps will be utilized more. Placing the bar on your shoulders behind your head, as a back squat, will utilize the hamstrings and gluteals more. Split squats and one-legged squats are great alternatives when a heavy load is not tolerated by the lower back, as the load can be reduced without affecting performance.
For any jumping, or plyometric, exercises, being able to land correctly is key to advancing in more intense drills. Landing is how injuries can occur; and as the feet hit the ground, bending at the hips, knees, and ankles will help to absorb the shock of hitting the ground. Beginners should spend the first two to three weeks of a program focusing on landing properly. Plyometrics can be done with two legs or one. However, performing any jump on one leg is more advanced and should be gradually progressed from two legs. Some two-legged jumps to start with are front cone hops, lateral cone hops, box jumps, and double leg hops. The height of the cone, or barrier, can increase as technique and power improve.
According to the National Strength and Conditioning Association, injuries may occur while performing squats due to incorrect form, previous joint injuries, fatigue or over-training. For plyometrics, the National Strength and Conditioning Association recommends the exercises are done on a shock-absorbing surface with at least 48 hours of rest between training days. Individuals should have a strength base prior to starting any advanced plyometric exercises, and high level exercises, such as depth jumps, should not be done by anyone who weighs more than 220 pounds.