This is an excerpt from Plyometrics by Donald A. Chu & Gregory Myer.
Best Warm-Up Drills
One of the basic tenets of all exercise programs is that major efforts of training should be preceded by lower-level activities. These warm-up activities can take various forms and can be general or specific in nature. The exercises of choice when using plyometric drills should be specific or related to the larger efforts. These warm-up drills are not classified as true plyometrics because they require less voluntary effort, focus, and concentration to complete. However, they are used to develop fundamental movement skills and raise the body's core temperature; therefore, they help prevent injury and are helpful in establishing motor patterns that will directly carry over to speed development and jumping ability.
Let's take a look at some of the activities that fit into the category of warm-up or submaximal plyometrics. Keep in mind that all of these drills are performed not as conditioning drills, but as skill enhancement drills aimed at teaching or rehearsing certain motor patterns. Therefore, they are performed over distances of 10 to 20 meters (or yards) with a relatively long recovery between exercises. A good general rule to use in this situation is to have the athlete perform the drill in one direction and walk back in the other. This allows adequate recovery as well as mental rehearsal for the next repetition.
Usually 8 to 12 exercises are considered an adequate amount of movement to elevate the core temperature of the body and form an adequate warm-up. Each exercise may be performed 2 to 4 times depending on the athletes' execution and learning. With a group of athletes, a coach can make administering the warm-up easier by placing individuals in groups according to ability and need for instruction.
These drills are intended to mimic running movements. They are designed to break down the act of running into its component parts. This allows the coach to stress parts such as posture, joint angles, range of motion, foot placement, and other biomechanical features that are often overlooked when athletes are simply asked to perform the whole activity. Several Canadian track and field coaches (Mach, McFarlane, Biancani) were early proponents of the use of these types of drills to enhance proper hip, thigh, and leg actions in preparation for and during running.
Many variations of jogging can be used to emphasize speed development because this activity can be easily modified to be plyometric in nature. The simple act of jogging on the toes with special emphasis on achieving quick ground reaction by not letting the heel touch the ground can be a mini-plyometric activity. Jogging with the legs straight and limiting knee flexion can teach the athlete to expect a sharp impact when performing maximal-effort plyometric drills.
Ankling is a specific jogging drill that involves using the elastic component of the calf musculature to improve speed of foot movement and decrease contact time with the ground during sprinting. The athlete uses a straight leg and keeps the ankle relatively rigid. The athlete moves forward with a straight leg and lands on the first third of a slightly plantar-flexed foot. At contact, the athlete quickly responds to the ground by pushing down against the ground surface and bringing the foot through at about the level of the other ankle (also known as stepping over the ankle). This movement is continued for the length of the prescribed distance.
Special effects can be achieved by using drills such as butt-kickers, which emphasize knee flexion and closing the angle of the knee by bringing the heel to the buttocks; these can be extremely useful when the athletes begin to work on the recovery phase of sprinting. This movement teaches athletes economy of movement and that the shortest lever they have to swing forward will speed up their ability to cycle or turn over the legs during running. Heel recovery is an essential ingredient in absolute speed development. This drill also is an excellent rehabilitation drill for assessing dynamic knee flexion range of motion. If the athlete does not have full and equal knee flexion in both legs when running at all-out speeds, the knee with less range will not swing through at the same speed nor will it fully extend upon landing. Therefore the stride on that side will be slightly shorter. In essence, the athlete will be running with a limp that can throw off the entire running mechanics and put the athlete at risk for a running injury involving the opposite leg or same side quadriceps/hamstrings complex.
Synchronization of limb movements is basic to normal motor development. So-called reciprocal movements occur between the legs and arms in running. Generally, efficient running requires a runner to move his left arm forward as the right leg comes forward, then switch limb movements to the opposite side of the body as he continues to move forward. This reciprocal motion is fundamental to the development of the athlete. Skipping drills require an exaggerated form of this reciprocal motion, which is often lost if not practiced. Because of the need to perform reciprocal limb movements and the emphasis on quick takeoff and landing during skipping, this activity is ideal as a submaximal plyometric activity that can be used to warm up athletes and prepare them for more complex skills.
Various forms of skipping are used to achieve explosive movements initiated by the calf-ankle complex, including the following:
- In straight-line skipping, the athlete initiates forward movement by quickly rising onto the toes of both feet and assuming a slight (10-degree) forward lean, then rapidly lifting the thigh to a position parallel to the ground. The ankle is dorsiflexed, pulled into the neutral position, and held while the foot is being lowered to the ground. The most important detail of this type of drill is that the foot, knee, and hip are in a single line or plane of movement. As the knee is being lifted into the up position, the opposite foot is extending to raise the athlete onto the toes of the opposite side; this drives the athlete's body up so that it briefly clears the ground surface. As soon as the leg and thigh hit parallel, a reversal of motion takes place; the leg extends, and the foot makes contact with the ground. The same action occurs on the opposite side. Keep in mind that the arms should be flexed to 90 degrees and will move forward in a reciprocal manner (opposite arm, opposite foot).
- Single-leg skipping is not only a drill but an assessment tool as well. In this movement, the action that occurs is the same as in straight-line skipping, but only one leg is allowed to drive up to parallel. This results in a small hop on the opposite side of the body. The athlete brings the thigh to parallel with enough force to lift the body off the ground. As the leg drops, the athlete prepares to repeat the motion on the same leg, using the arm on the opposite side to help propel himself up and forward. Because this motion requires the isolation of right versus left, it will allow for the assessment of each leg regarding speed of movement, strength to bring the thigh to parallel, and endurance and repeatability of each leg.
- Skipping with a pop-off is the same motion as in straight-line skipping, but the motion on the opposite side is exaggerated to emphasize complete ankle plantar flexion, and the lift or pop off the ground is greater. Maximal controlled height should be achieved with both legs for the prescribed distance.
Submaximal footwork drills developed and presented by John Frappier (1995) in his Acceleration Training program are useful supplements to plyometric conditioning programs. However, these drills require hip movement and quick changes of direction that can also make them useful as warm-up drills. Drills such as shuttle drills, multidirectional side-shuffle drills, and drop-step drills are continuations of these simple and brief footwork movements that rely largely on the ankle complex for propulsion—and they all fit under this heading.
These drills are taken from the basic exercise movement known as the lunge. When used as submaximal drills, these exercises can take many forms, such as forward, side, crossover, disassociated multidirectional, reverse, and walking lunges. They can (and should always) be used as preparation before doing long amplitude jumps. These drills can be extremely useful in developing basic strength in the upper hip and thigh areas when used with simple body weight.
Read more from Plyometrics by Donald A. Chu and Gregory Myer.