Of all the topics I’ve written about, this article may have the most immediate impact on players at every level. If you’re looking to hit the ball farther or throw the ball harder instantly, I highly recommend reading on.
I’ve always enjoyed playing tennis and watching professional matches to pick up tips and improve my overall game. However, when tuning in to men’s and women’s matches, I often turn the volume down due to the constant grunting and screaming from players. From short grunts to loud screams with each serve or ground stroke, it’s distracting and, frankly, annoying.
But one day, while watching a match, I couldn’t take it anymore. I decided to go online and search for an answer to a question that had been on my mind for a while: Why do tennis players grunt and scream?
To my surprise, I learned that there are several logical reasons behind all the noise. In fact, the majority of these reasons are rooted in science.
The Science Behind Grunting
Studies have shown that tennis players experience increased racket speed and power when they make a noise at the moment they hit the ball. Forcefully exhaling while engaging the core muscles can lead to greater power. This effect isn’t just limited to tennis, though—grunting offers several competitive advantages that can improve performance in various sports.
The Softball Experiment
After diving into the science of grunting, I decided to test its effect on hitting and pitching in softball. Armed with a bat speed sensor, I tested players on a college softball team. The results were astonishing.
First, I asked each player to take a few swings without making any noise. Then, I instructed them to add a grunt when they hit the ball. Every player saw an immediate increase in bat speed.
- For hitters with high bat speeds (70+ mph or 80+ mph), the increase averaged 2–4 mph.
- For players with lower bat speeds, the increase was even more significant, averaging 4–6 mph.
The players were thrilled and reported that they could feel the added power during their grunting swings. I reminded them that, according to ESPN Sports Science, every additional 5 mph of bat speed translates to an extra 25 feet of distance. That could make the difference between a single and a double, or a double and a home run.
Excited by these results, I conducted further tests with a junior college softball team. Again, every hitter saw an increase in bat speed and power, with two players recording an impressive 6+ mph increase in bat speed.
One particularly memorable example came from a high school hitter. Her grunts were nearly undetectable, but after some encouragement to let loose, her bat speed shot up. Her confidence grew as she felt the power surge with each swing.
It Also Works For Pitchers
It wasn’t just hitters who benefited. I invited a college pitching coach to test grunting with her pitchers, and the results were similar. By incorporating a grunt into their pitching motion, players saw an increase of 2–4 mph in pitch speed.
Coaches at every level work tirelessly with their pitchers to add velocity, often using conditioning, drills, and weighted balls. Grunting, however, requires no additional skill development, making it a valuable tool to add to the pitcher’s toolkit.
Why Grunting Works
The early results of my bat speed tests were compelling enough to spur deeper research into why grunting increases power. It turns out that athletes in many sports grunt to enhance their performance.
- Football players grunt when blocking or tackling.
- Martial artists make noise when executing powerful moves or breaking boards.
- Track athletes, especially shot putters and discus throwers, grunt to optimize their throws.
- Weightlifters have been grunting for ages to boost strength and power.
In fact, an editorial in Men’s Health magazine explains that primitive vocalizations, like grunting, trigger the fight-or-flight response, recruiting more muscle fibers during intense movements. Athletes who grunt channel their inner animal, helping them instantly perform at a higher level. A Drexel University study found that grunting during lifting could increase static handgrip strength by up to 25%.
My hitters are definitely channeling their inner animals as they incorporate this into their swing sequence.
More Science Behind Grunting’s Benefits
In addition to the scientific research supporting the power gains from grunting, two additional studies caught my attention.
- Grunting Doesn’t Drain Oxygen: One study found that tennis players who grunted experienced an average power increase of 3.8% compared to those who stayed silent. Remarkably, the grunters didn’t expend any more oxygen than the silent players. This should be good news for coaches who worry that grunting might tire players out quicker.
- Psychological Edge: Another study revealed that grunting gave players a psychological advantage by distracting their opponents. In tennis, this slowed opponents’ responses, leading to less accurate returns. In softball, this could affect a pitcher’s or infielder’s reaction time—giving the hitter a significant edge.
Other Benefits of Grunting
- Improved Focus, Rhythm, and Timing: Hitters who grunt are often more focused and “on time” with the pitch. The act of grunting at the moment of impact keeps them in sync with the timing of their swing, improving rhythm. It also adds an important component to the swing sequence without disrupting the mechanics.
You would think if hitters are grunting when they make contact with the ball, the swing sequence would be choppy or less fluid. The opposite is true. It doesn’t affect the mechanics leading up to the grunt or the finish after the grunt.
- Consistency: Improved focus and rhythm lead to greater consistency. I’ve observed that hitters who grunt are more accurate and controlled, even if they’ve historically struggled with consistency. Grunting forces hitters to be more aware of the path of the pitch to ensure they grunt at just the right time.
- Increased Confidence: While I can’t scientifically prove it, I’ve noticed that hitters who grunt develop more confidence. They realize the extra power they’re generating, and each successful swing boosts their belief in their abilities. This increased confidence leads to better overall performance.
Grunting in Games
After seeing the effects in practice, I decided to test whether grunting would carry over into actual games. The results were dramatic—hitters and pitchers who incorporated grunting into their game play performed with more power and consistency.
Some hitters are bashful and are hesitant to grunt in games, while others tell me they grunt in their mind. This will improve their focus, rhythm, and timing, but it doesn’t help them hit the ball farther.
Hitters who are confident enough to grunt in games are always rewarded. A senior hitter on a college team I coached, known for being the loudest voice in the dugout, hit a towering grand slam, one of the longest home runs of her college career. When I asked if she grunted during the swing, she smiled and said, “Of course!”
Get Noisy!
After reviewing the research and seeing firsthand the benefits of grunting, I can only conclude that this is a secret weapon that shouldn’t remain secret any longer. I can’t wait to HEAR players at all levels hitting bombs and throwing harder, all thanks to the power of grunting!
About Paul Petricca
In addition to writing this hitting blog, Paul is a hitting coach and the author of the book Hitting With Torque: For Baseball And Softball Hitters and his new children’s book Going Going Gone!. He is also a public speaker and provides unique customer engagement training through his company Torque Consulting.