IN-GAME HEART RATE RESPONSES AMONG PROFESSIONAL BASEBALL STARTING PITCHERS
“…baseball pitching among professional starting baseball pitchers does seem to be primarily anaerobic in nature…”
Let’s talk pitching and science, shall we?
First, let’s talk about the aerobic energy system. This system predominates during long, low-intensity activities where oxygen is readily available. Usually, once an activity reaches over 60 seconds, it becomes an aerobic event.
Now, let’s imagine ourselves on the mound.
How long does it take for you to complete your windup and throw the ball to the catcher? Possibly 6 seconds, generously?
SO, why is it, that many coaches still think that pitching is an AEROBIC event? Here is where we are going to learn why pitching is an ANAEROBIC event.
UNDERSTANDING SIMPLE PHYSIOLOGY
As stated, the aerobic energy system dominates once an activity reaches above 60 seconds of work. The ATP-PC and Glycolytic systems dominate during activities that last from 1-10 seconds and 10-30 seconds, respectively.
Pitching, therefore, mainly stresses the ATP-PC system. An anaerobic activity is characterized as a “high-intensity” activity.
One way to determine the intensity of an activity is to measure an individual’s heart rate (HR). The most popular way of estimating HRmax is the age-adjusted HR formula (220-age).
Our HR is also directly related to the maximal amount of oxygen that we consume (VO2 max). Therefore, the more intense the activity, the more oxygen we must consume.
According to this new study, there is little research looking at the physiological intensity of baseball pitching during real-time. 
Many of the few studies that have investigated in-game HR collected data from a simulated game or bullpen session. Not to say that this information is not valuable, but if we want to generalize data to the actual game as much as possible, it must be as specific as possible.
Those previous studies have shown that pitchers (in a simulated game or bullpen session) had an average HR of above 75% their HRmax. 
To date, this is the first study published that has data from multiple professional baseball pitches during a live game!
The researchers aimed to quantify the intensity of baseball pitching during a live game and provide any potential differences between home and away starts.
THE STUDY ITSELF
This study included 16 professional baseball starting pitchers (age = 22.1 +/- 1.3 years). This age range is important because the researchers used the age-adjusted formula. If there were large differences in age, then the results would be a bit skewed due to physiological differences we see as the aging process goes on.
The in-game data was recorded with Zephyr Technology: a bio-harness that has been used in clinical research.
Note: It’s important to do additional research on how the researchers collected their data because the device(s) they use may or may not be reliable or valid.
The average in-game %HRmax in this present study was 84.8% and was significantly higher during the first inning of a home start in comparison to an away start. The first two innings of both home and away starts were both higher than any other following inning.
This initial rapid increase in HR in both home and away starts is probably stemming from the psychological component of pitching, and which is why it started to taper off as the game went on. However, it is important to note that even in the 6th inning, the average %HRmax was 82.9%, indicating that pitching is indeed an anaerobic, high-intensity task!
These results also indicate that HR in the first two innings is moderated by the location of the game (home vs. away), so we cannot completely say that this high percentage of HRmax solely comes from the action of throwing a baseball towards the plate.
SO, now that we have science-backed data to confirm that pitching is indeed an anaerobic event, how should we apply this information?
Strength and Conditioning Professionals and Baseball coaches alike should understand that interval training, short sprints, and other high-intensity exercises are most appropriate to train the baseball pitcher from a physiological standpoint.
Lastly, as the researchers mentioned in the discussion, future research should look further into the psychological effects that pitching has on the body from a physiological standpoint.
Jarad Vollkommer, CSCS
- Cornell, D.J., Paxson, J.L., Caplinger, R.A., Seligman, J.R., Davis, N.A., Flees, R.J., & Ebersole, K.T. (2017). In-game heart rate responses among professional baseball starting pitchers. Journal of Strength and Conditioning Research 31(1), 24-29.