Plyometric
Sometimes stepping backward to move forward isn’t totally bad. As a young soccer player, probably about 8 years a go, our coach brought in a “speed expert”.
He asked one of the players to perform a sprint and asked the rest of us “what did you notice about that sprint?” We came up with all sorts of answers except the one he was looking for.
The answer he gave us was that when the player reacted to the call to sprint, he took a small step back, and according to the coach this cost him time.
This lost time could be critical to the outcome of a contest when two players are reacting and challenging for the ball. The small step back he was referring to is known as the “plyo-step” (Lee Taft) or “False Step”.
The speed coach then tried to teach us some drills to eliminate the plyo-step which were centred around body position.
Unfortunately, he had little success with our particular group. Furthermore, as soccer is a random multi-directional game, it is hard to position your body to eliminate the plyo-step when you don’t know what direction you will be moving in!
Interestingly, a piece of research by Brown and Vescovi (2004) found that the plyo-step allows for the greater force development with the shortest impulse time compared to the “drop and go” and “staggered step” techniques. This doesn’t mean to say that the plyo-step your performing correct. Lee Taft offers some technical advice in the International Youth Conditioning Association Developmental Essentials.
Your push off leg should be aligned directly behind the body. Your upper body and shoulders should assume a forward lean to line up the angle of push-off. The aim is then to generate lots of power into the ground by aggressive arm and knee actions so to transfer force into the push off leg.
If your looking at improving acceleration, it’s worth analysing your starting technique.
Alan Ruddock CSCS, YCS
The buzz word within sports performance these days is “plyometric” training and the use plyometric training has become widespread in many sports performance programmes.
When implemented in the correct manner plyometric training is effective for improving explosive power (impulse is the correct term).
The aim of plyometric training is to reduce the time the foot is in contact with the ground which allows for a more efficient transfer of energy in the direction of movement.
To be considered plyometric the exercise must have a ground contact time of less than 0.2-s. Unfortunately many “plyometric” drills prescribed by coaches do not fulfil this criteria.
However, sprinting does. When running at high speed ground contact times are between 0.08 – 0.20-s with ground reaction forces around 3 times body weight.
A recently published study by researchers from the University of Zagreb, Croatia looked at the effects of sprint and plyometric training on muscle function and athletic performance.
Ninety three male physical education students were assigned to a plyometric group (PG), sprint group (SG) or combined plyometric and sprint group (CG).
The plyometric group undertook the following training three times per week for 10 weeks.
Week – Exercise – Sets x Reps
1 40-cm hurdle jumps 5 x 10
2 40-cm hurdle jumps 7 x 10
3 40-cm hurdle jumps 10 x 10
4 60-cm hurdle jumps 5 x 10
5 60-cm hurdle jumps 7 x 10
6 Unloading week (rest)
7 60-cm hurdle jumps 10 x 10
8 40-cm drop jumps 4 x 10
9 40-cm drop jumps 4 x 10
10 40-cm drop jumps 4 x 10
11 40-cm drop jumps 4 x 10
The sprint group training undertook the following training three times per week for 10 weeks.
Week – Exercise – Sets x Reps
1 10-m sprint 3 x 3
2 10-m sprint 4 x 3
3 20-m sprint 3 x 3
4 20-m sprint 4 x 3
5 30-m sprint 3 x 3
6 Unloading week (rest)
7 30-m sprint 4 x 3
8 40-m sprint 3 x 3
9 40-m sprint 4 x 3
10 50-m sprint 3 x 3
11 50-m sprint 4 x 3
The researchers found that isometric squat strength, squat jump power and counter movement jump power was significantly improved in the sprint group only.
Both plyometric training and sprint training groups significantly improved performance in the squat jump countermovement jump and drop jump index.
So what does this tell us? If we want to improve performance in pretty much any sport improving explosive power is the key. This piece of research indicates that sprint training may be more advantageous than plyometric training alone when aiming to improve explosive power.
Reference
Markovic, G., Jukic,I., Milanovic, D. and Metikos, D. (2007). Effects of sprint and plyometric training on muscle function and athletic performance. Journal of Strength and Conditioning Research, 21, 543 – 549.
