In high school, our crew team started each session with a warm-up routine that included 3 sets of 20 tuck jumps. Coach called them “jumpies.” We stood with feet shoulder-width apart, jumped as high as we could, tucking our legs toward our chests, and repeated the movement as quickly as possible upon landing. Little did I know then that these were plyometric exercises, designed to enhance our athletic abilities alongside rowing, running, and strength training.
Plyometric training gained popularity in the 1960s, championed by Russian coach Yuri Verkhoshansky. It involves rapid sequential muscle contractions, storing and applying elastic energy, aiming to improve speed and strength. Coaches across various sports incorporate plyometrics like vertical jumps, box jumps, and squat jumps. For endurance athletes, plyometrics offer benefits like better coordination, agility, strength, power, speed, and running economy.
What is Plyometric Training?
Plyometric training, also known as explosive strength training, engages both eccentric (lengthening) and concentric (shortening) muscle contractions, intensifying workouts compared to traditional strength training. The force exerted can be up to 5-7 times our body weight per repetition, which means we need to take a gradual and systematic introduction into training regimens. For injury-prone athletes, a plyometric regimen may not be a good idea. Talk with your coach before adding this type of training to your routine.
Plyometrics were originally thought to enhance anaerobic power but have also been found to improve aerobic power, akin to muscular endurance. This aligns with the benefits seen in running economy, which refers to oxygen consumption during steady-state running at a given velocity.
Three main explanations for how plyometrics might enhance our economy:
- improved muscle power
- more effective stretch-shortening cycle (SSC)
- neuromuscular learning effects.
Plyometric training mimics running mechanics, increasing the force generated with each stride. Studies show improvements in sprint performances, which correlate with better running economy over various distances. Additionally, plyometrics can enhance muscle stiffness, improving the efficiency of the stretch-shortening cycle and reducing the energy cost of running. Running involves cycles of eccentric (stretching) and concentric (shortening) muscle contractions. Efforts to make this cycle more efficient permit soft tissues to store and release elastic energy, which in turn can reduce the overall energy cost of running (Bonacci et al., 2009). A key to a more efficient SSC is muscle stiffness, which allows a runner to make the most of stored elastic energy.
Neuromuscular improvements from plyometrics lead to more efficient muscle mechanics and activation, aiding in faster transitions from braking to propulsion during running. This improves running economy, especially at faster speeds akin to high-intensity training or competition efforts. Plyometric training also helps correct neuromotor control inefficiencies, reducing injury risk by improving biomechanics.
Injury prevention is another benefit of plyometric training, particularly for ACL injuries, which are common among female athletes. Plyometrics, combined with other strengthening exercises and running, have been shown to reduce knee pain complaints and alter movement patterns to reduce injury risk. It’s very important, however, to have the base of strength properly built before introducing these types of power moves.
Plyometric training also contributes to bone density, particularly in children and pre-menopausal women, reducing the risk of stress fractures.
Introducing Plyometric Training
When incorporating plyometrics into a training schedule, start slowly and progress gradually. It’s essential to engage in weight training beforehand and introduce plyometrics systematically to prevent injury. Most athletes will need about 8-12 weeks of previous strength training program before introducing plyometrics into the mix.
Experts recommend coupling plyometric training with other resistance training and periodizing its inclusion in training plans. Sample plyometric exercises include tuck jumps, squat jumps, lateral jumps, power skipping, leg bounding, and vertical jumps. Jump rope and agility drills can also provide a plyometric training stimulus.
I like to include some plyometric work with core work or bodyweight functional training. This can provide a well-rounded program for many athletes.
When selecting plyometric exercises, consider sport-specific movements and skills. Warm-up thoroughly and progressively increase difficulty and duration over a 6-10 week program. Always be mindful of the force exerted on the body to prevent injuries. The timing also matters.