Plyometrics n. A type of exercise training designed to produce fast, powerful movements and improve the functions of the nervous system, generally for the purpose of improving athletic performance.
Or, if you like, the more explosively you can move your legs, the quicker you can run over any distance and the less effort you will have to put in to get yourself there. Which we would all like. Very much.
But what is it, really? Plyometrics, commonly referred to as 'plyos' by people who do them and are probably already running faster (and further) than you, is based on the theory of stimulating a muscle to reach maximum force in minimum time. It's all about being powerful. If the muscles in your legs are like springs, then plyometrics will make them springier, says specialist strength and conditioning coach Jamie Sawyer (jamiesawyer.co.uk).
"To get a clearer idea of how plyos work, think of stretching out a coiled spring until it's fully unravelled, and then letting it go," says Sawyer. "Immense levels of stored energy are released as the spring recoils."
The further you can stretch those springs and the quicker they can reach full extension, the more power they will generate each and every time they snap back.
That sort of instant energy sounds ideal for the choppy power required for short distances, doesn't it? Say, 100m. But do the dynamic benefits of faster-firing muscles translate over any distance and at any level?
The answer is a predictably instant one: yes.
"Runners using plyometrics will see increases in not only their power output but their strength endurance, allowing them to maintain strong running form for longer, even as they tire," says running coach Nick Anderson (runningwithus.com). Better form means faster times, and you know what that means: "One thing will always stand true," says Phil Learney, strength and conditioning coach at The Third Space fitness club (thethirdspace.com). "The fastest athlete will always win."
But winning isn't everything. Plyos will benefit your performance, whether you're a fun-runner or taking the business altogether very seriously. "Runners undergoing a plyo training programme will see an improvement in running economy," says Sawyer. "The major muscles in your legs will be producing power more efficiently, requiring less of the oxygen you're taking in and so increasing your overall endurance."
Even better is that in the process of plyo training for your new personal best, you'll be protecting yourself from the sort of niggling tendon injury that can turn that tightly coiled spring into an old elastic band. Plyometric training increases the tensile strength of the tissues used," says Sawyer. "Therefore you will see a reduction in injuries on top of the improvements in athletic performance, muscle economy and power output of each footstrike."
Essentially, plyometric training works by decreasing the amount of time between the stretching of the muscles and the initiation of the powerful contraction - in other words, the length of time your foot spends on the floor. In the repetitive stretching and contraction of running, working on that sequence is precisely what will make the crucial difference.
"Considering that an athlete running at a six-minute-per-mile pace will spend 0.44 seconds per running stride in contact with the ground, shaving time off this will simply make you faster," says Learney.
The less time you spend rooted to the ground, the more time you're covering it by moving forward.
A plyometric movement consists of three phases, which can be illustrated by imagining a rubber ball dropping to the floor. The first stage is when the ball is falling - this is the Pre-Stretch phase, and constitutes the lengthening of the muscle that generates and stores elastic energy. When the ball hits the floor, this is the Amortisation phase, the momentary 'squashing' upon impact. The shorter this stage is, the more power you'll have for the next - which is the Concentric phase. Here, the ball propels itself off the ground - or, in body terms, the muscle contracts, exploding with elastic energy and propelling you forward with a powerful movement.Much like that rubber ball, your muscles store and return energy very efficiently. The softer the ball, the more this energy is dissipated upon contact with the floor. The harder the ball, the more power is transferred directly to your running performance. "Plyos educate your legs to become better at absorbing shock, quicker at transferring the impact into power and more efficient at using that power in a straight line," says Anderson.
But there is something that's always working against you: your brain. Plyometric training is as much neuromuscular as it is bio-mechanical.
With each stride and footstrike, neuromuscular and sensory feedback is relayed to your central nervous system by sensitive nerve spindles in the muscle, which gauge the force exerted.
This information is both a blessing and a curse. One of the major limiting factors on your elastic energy is that those spindles communicate with your brain to prevent muscular overexertion. In short, it stops you from stretching the spring as far as you can in case it breaks. Of course, you don't want an injury, so this is a good thing.
An even better thing is that plyos naturally increase this threshold to allow for a greater range of stretch and a more explosive firing of the muscle. "Over time, plyos will even alter the timing of the motor units that control when your muscles fire, conditioning the neurons to activate in a single, more powerful surge, rather than in a random series of contractions," says Anderson.
With great power comes great responsibility, and that responsibility isto train safely. Although plyo drills are body weight exercises, you should start slowly and focus on technique. "The main dangers almost entirely relate to poor execution and preparation," says Anderson. "The athlete must demonstrate enough lower leg strength to absorb the excessive weight-bearing forces that plyo drills can momentarily place upon the body."
For that reason, plyo drills shouldn't be added to your training programme until adequate strength in your legs has been established. "It is recommended that you are able to perform five repetitions of a back squat [squatting while holding a dumbbell with the bar behind your neck], holding 60 per cent of your body weight, before doing plyometrics to ensure you can execute the exercises with the required power and dynamism and without compromising form," adds Learney. Furthermore, always make sure you are wearing well-cushioned shoes and perform the drills on a yielding surface, such as a running track, sprung floor or even grass - as long as the ground is flat and not too hard.
Nor is it wise to get explosive without warming up your ammo first. "The large forces involved with plyometrics mean the risk of injury is higher if you don't prepare properly," warns Learney. "A plyo session must be preceded by a 15-minute dynamic warm-up routine. This should include mobility sequences specific to running."
Recovery from a plyometric exercise will take anywhere between 48 and 72 hours, so do a maximum of two sessions per week, keeping in mind that you will want to factor in a recovery the day after. Resting your muscles is as important for their development as the plyometric movements themselves.
So get ready to explode. "As with all new methods of training, the speed of progress is dependent on the fitness and competence of the athlete," explains Sawyer. "But generally speaking, two sessions a week for six weeks will demonstrate significant improvement."
The warm-up and workout that follow provide the fuse to more explosive strides, improved long-distance endurance and faster running. All you have to do is light it.
The Warm-Up (subscriber-only) | The Drills (subscriber-only)
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