‘Watt’ Is Applied Power
March 18, 2016 | Abbi Nicolella
PITTSBURGH – In his research study, A Review of Power Output Studies of Olympic and Powerlifting: Methodology, Performance, Prediction, and Evaluation Tests, Dr. John Garhammer, PhD, professor Emeritus of Kinesiology at California State University Long Beach, measured the total energy expenditure and rate of energy expenditure (power output) of various weightlifting and powerlifting movements.
As Garhammer writes, “…in many sport, work and recreational activities power output has some relationship to performance.”
This is certainly true with baseball and more specifically, SwingTracker.
Today we will examine the specifics of Garhammer’s research and see how they can be applied and understood, relative to the baseball swing and to SwingTracker.
In his study, Garhammer was able to deduce the power output – in watts – of specific lifts. The ones we will focus on today are the benchpress, squat and deadlift.
In testing skilled, elite weightlifters Garhammer discovered that the power output in terms of the benchpress for a male during a one repetition, max load lift is four watts per kilogram of bodyweight. As it applies to the deadlift and squat, the number increases to 12 watts per kilogram of bodyweight.
Taking those numbers and applying them to different body weights, we see the power output for an 85 kg male (187 lbs.) is 340 watts for the benchpress and 1,020 watts for the the deadlift and squat (these numbers are represented in the chart at the top of the page).
With that in mind, let’s take a look at SwingTracker and how those numbers apply.
In terms of power output for SwingTracker, three different Power metrics are measured: Max Acceleration, Impact Momentum and Applied Power – the last of which we will be discussing today, in terms of Warhammer’s study.
Applied Power measures the amount of watts – or energy expenditure – one applies to the bat during the swing. This gets to the core of being able to impart the highest amount of exit velocity on the ball by A) swinging a bat fast and B) swinging a heavy bat fast.
In order to accelerate a heavy bat up to the necessary speed so that the batter doesn’t lose bat speed or hand speed, the batter has to apply more power – i.e. watts/energy – to the bat during the swing. Applied Power, relative to SwingTracker, gets to the ability of the batter to swing the heaviest bat possible in the fastest manner to meet up with the pitcher’s throw.
Going back to Garhammer’s study, a 187 lb. male, who is an elite-level weightlifter applies 1,020 watts of energy during a squat of a deadlift. Similarly, the Top 20% of SwingTracker users at the high school varsity skill level apply an average of 1,185 watts of energy to the bat during the swing, while the average high school varsity skill level applies 830 watts of energy.
While the two actions (baseball swing, squat/deadlift) are different, the initial thought process for coaches or players should follow a qualitative process first before then using a quantitative perspective:
“I can visually see how much force and effort is being applied as the 187 lb. male is trying to squat that very heavy amount of weight.”
“I can take that visualization and then understand from a quantitative point of view how much energy is being transferred from the batter to the bat, and subsequently the ball”
Moreover, the idea behind Applied Power, relative to SwingTracker, is being able to measure the energy output of the swing relative to the bat weight + bat speed/hand speed. When taking this into account, we can see the similarities behind the weightlifting comparison.
Just because someone physically tries harder doesn’t mean their power output (watts) will automatically increase to the level they would like.
Let’s say, for instance, we have two individuals who both weigh 85 kg. One person’s one rep, max squat is 225 lbs., while another person’s one rep, max squat is 135 lbs. If we were to measure the energy output of each of these lifts, we would see the person who can lift 225 lbs. is producing a higher amount of watts than the person lifting 135 lbs. This is because more energy is required in order to lift a heavier amount of weight.
In terms of baseball, more energy is required to swing a heavier bat the same speed as a lighter bat. So with that knowledge in hand, we can look at Applied Power and deduce how much energy is being applied to the bat and determine if the batter can get the bat up to speed. From there, we can determine if a lighter, heavier or same weight bat should be used.
Moreover, while weightlifting metrics are determined by the amount of weight one can lift (no asks how many watts one produces during a lift, they ask how much can you lift), Applied Power is determined by watts, but indirectly determined by weight (specifically the weight of the bat).
Since the bat weight increases by ounces and not pounds, it requires more of a sample size (i.e. – more swings spread out over time) to determine what a player’s Applied Power levels are.
Ultimately, the main takeaways from this look into Applied Power are the following:
- Applied Power is measured in watts, which is another way of saying a transfer of energy (in this case from the batter to the bat, then the ball)
- This metric should be correlated and thought of in conjunction with other SwingTracker metric data (specifically Max Barrel Speed, Max Acceleration and Impact Momentum) in order to better understand it and get the most use from it
- The amount of energy transfer in watts for the baseball swing for elite-level high school players is roughly the same as the amount of energy transfer in watts for an 187 lb., elite-level Olympic weightlifter who is attempting a one-rep squat or deadlift
- Applied Power gets to the ability of the batter to swing the heaviest bat possible in the fastest manner to meet up with the pitcher’s throw.
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