There is not a sport or performance where strength and power aren’t required.
They are strictly linked and the development of one of them results in an enhacement of the other. While strength is the ability of your muscle to do certain work, power is the result of strength and velocity, that is the ability of the muscles to express strength in the time unit (WORK/TIME = POWER), and it can be used as an indicator of muscle efficiency.
However the development of both needs a different kind of stimuli.
We have already talked about strength and, even it is an huge and always interesting topic, this time we dedicate this article to POWER or SPEED-STRENGTH and STRENGTH-SPEED.
When you are training Power, the most important thing you have to think about is how to move with intent, that means that you have to be as fast as possible, always maintaining a proper technique in the movement.
The intensity or the percentage of load relating to your 1RM (%1RM), depends on the exercise you are going to do. And this is another big issue: Which are the best exercises for maximum power development? I am sorry but, as usual, the answer is: It depends!
In training what really matters is the overall goal. Are you an olympic lifter? A sprinter? A football player? A power lifter? Every sport has different specific features so even the physiological bases are the same, the choice of the exercises, the intensities and the distribution of the loads depends on the specific goals dedicated to your sport.
The target of Olympic Lifting athletes is to improve in their discipline, but for every other sport it is to increase SPEED-STRENGTH, STRENGTH-SPEED, and EXPLOSIVENESS, because it results in an increased RATE OF FORCE DEVELOPMENT (reduction of the time within Maximum Force is reached).
In field sports, for instance, it is translated with a reduction of the GROUND CONTACT TIME and in combat sports in more effective shots.
SPEED-STRENGTH RATE OF FORCE DEVELOPMENT SPORT PERFORMANCE
Whenever you have understood the specific power output that you need, you can calculate the power potential of any exercise and then choose the right one. Power potential must be fixed considering the following equation 1)(Garhammer, 1994):
(MASS (load + lifters’s body weight) X GRAVITY (9,81 m/s/s) X HEIGHT) / TIME = POWER
This equation is the reason why some exercises fit better than others for power development.
Exercises like bench press, squat and dead lift are defined as “strength exercise” because they involve large muscle mass and allow to use very high loads. Olympic lifts, jumps, throwing and sprints are defined as “power exercises” instead. The difference between these two groups of exercises is that the first one entails a deceleration phase during the concentric portion of the lift that doesn’t occur in the other group. This deceleration is an automatic and involuntary system of protection of the joints settled in by our body. This doens’t occur when jumping or throwing, as they are “open-ended” exercises and acceleration lasts for the entire range of movement.
However, explosive bench press and squat, can also be prescribed sometime with the addiction of a compound resistance, by using equipment like chains and elastic bands.
Whatever exercise you choose, power training has a key parameter that is the PEAK POWER (or Peak Velocity): the fastest point during the concentric phase of the movement. In most of the cases, if a certain level of velocity isn’t reached, the performance will fail. This happens for every rep of the set. So it is very important to monitor velocity during the entire set and if it drops under the fixed level (20-30%???), it means that it’s time to stop and rest.
Peak Power is also the best indicator in order to fix the right training load. Normaly coaches prescribe loads as percentages of 1RM, but it doens’t correspond to the load that ensures the maximum power development as Peak Power is.
Reserches have shown that velocities for Power development go from 0,75 m/s to 1,3 m/s. 2)Gonzalez-Badillo JJ – Sanchez Medina L. Movement Velocity as a measure of loading intensity in resistance training. International Journal of Sport Medicine. 3)Velocity Based Training. JB Mann. NCAA
That being said, let’s talk about practice comparing three exercises and trying to understand the differences: Back Squat with barbell, Squat Jumps and Snatch with Barbell.
BACK SQUAT with barbell
Back squat is a typical “strength exercise” and as said above, it is a movement that entails a deceleration, in order to protect joints. However it can be used also for power development. The intensities usually go from 50% to 70% of 1RM 4)(Wilson et al. 1989), that correspond to a Mean Velocity from 0,75 to 1,0 m/s – Peak Velocity from 0,8 to 0,54 m/s 5)“The optimal training load for the development of dynamic athletic performance” Wilson GJ, Newton RU, Murphy AJ, Humphries BJ. Med Sci Sports Exerc.
Under these intensities you wouldn’t be able to express a powerful movement (you’d be too fast) and over them the movement would be too slow. In both cases you would miss the target of the training.
Many researches have shown that squat jumps can be a great tool for power developments.
It has no deceleration phase, so the athlete can jump as high as he can, developing huge levels of power.
It has the advantage to be easier to be performed compared to other typical power exercises, like olympic lifts, where technique skills can influence the power output by 20% or more, even in a skilled athlete 6)(Carl Vall – freelapusa.com).
Furthermore, it has been proven that the maximal power output during a loaded jump squat could equate very similar values of the ones reached during olympic lifts, for subjects of lower strength levels or lower skills 7)(Hakkinen & Komi (1985a; 1985b).
Keep in mind that Power target must be calculated adding the body weight of the athlete to the barbell weight.
Intensity recommended when performing jumps go from body weight to 30-40% 1RM (Mean Velocity from 1,0 to 1,3 m/s – Peak Velocity from 3,1 to 2,35 m/s). 8)“Normative data for mechanical variables during loaded and unloaded CMJ” Taylor S, Taylor K. Journal of Australian S&C
SNATCH with barbell
Olympic lifts are known as the most powerful movements. They are deemed as full ROM movement, because they essentially are a jump, even a certain deceleration phase exists whenever the barbell has to be “caught”.
The catch of the barbell is quite a technical skill and that’s the reason why non-professional weight-lifters can achieve great velocity and power outputs during the pull and then they fail the catch. Peak velocity occurs at the top of the second pull. The athletes accelerate up to this point and decelerates beyond this point 9)(Horbili et al. 2014).
Techinical skills require time for learning and this could be a drawback in sports like football, rugby and so on. Olympic lifts also need an excellent joint mobilty (wrist, shoulder, elbow, ankle, knee…) and field sport athletes get injured frequently. Injuries and the lack of technique can greatly affect the movement during an olympic lift and then the power output.
However looking at the Peak Power value you can avoid to foul up the output of the value, because it reflects the higher powerful level reached during the lift and it is not affected by the deceleration occuring due to the miss of the catch.
A loading of 80-90% 1Rm during the Snatch is considered an optimal intensity for speed-strength development (Mean Velocity about 1,00-1,3 m/s – Peak Velocity between 1,6 – 1,9 m/s)”10)Reviewing current knowledge in snatch performance and technique: the need for future directions in applied research” Lorenzen C., Wilson CJ, Saunders JE, Williams MD – Journal of Strength and Conditioning Research.
In the chart below you can see some values of reference expressed in Absolute Watts and Relative Watts (W/KG) 11)Garhammer & McLaughlin – Poprawski – Hakkinen & Komi
|Heavyweight males||Full Squat||900||12|
|Explosive strength trained males||Single loaded Jump||3559||32,9|
|Heavy strength trained males||Single loaded Jump||1910||27|
|Elite-developing rugby line-out jumpers||Single loaded Jump||1869||16,3|
- Velocity zone for Power development is: 0,75 m/s – 1,3 m/s;
- Different sports have specific features that influence the specific demand of power;
- Chose exercises that don’t entail a deceleration phase and allow the highest Peak Power;
- Individual differences also must be taken into account before prescribing loads (weight and height of the athlete);
- Technical skills and health condition of the athlete are also key parameters that can affect the power output.
References [ + ]
|2.||↑||Gonzalez-Badillo JJ – Sanchez Medina L. Movement Velocity as a measure of loading intensity in resistance training. International Journal of Sport Medicine.|
|3.||↑||Velocity Based Training. JB Mann. NCAA|
|4.||↑||(Wilson et al. 1989|
|5.||↑||“The optimal training load for the development of dynamic athletic performance” Wilson GJ, Newton RU, Murphy AJ, Humphries BJ. Med Sci Sports Exerc.|
|6.||↑||(Carl Vall – freelapusa.com|
|7.||↑||(Hakkinen & Komi (1985a; 1985b|
|8.||↑||“Normative data for mechanical variables during loaded and unloaded CMJ” Taylor S, Taylor K. Journal of Australian S&C|
|9.||↑||(Horbili et al. 2014|
|10.||↑||Reviewing current knowledge in snatch performance and technique: the need for future directions in applied research” Lorenzen C., Wilson CJ, Saunders JE, Williams MD – Journal of Strength and Conditioning Research.|
|11.||↑||Garhammer & McLaughlin – Poprawski – Hakkinen & Komi|