Why Swimmer's Slap their Arms before a Race

The explosive start of a swim race requires a 0 to 100% effort at the beep of a horn. From the starting blocks, the swimmer's legs essentially perform a maximal broad jump while the arms shoot overhead into a streamline position. Power, reaction speed, mobility, and aerodynamics are several of the necessities to a strong start, and a strong start is essential to a successful race. The physical and mental preparation before a race is highly important.  

​For many swimmer's, part of this race preparation involves swinging their arms in circles and slapping their arms around their body. These large warm-up movements are so common that even Michael Phelps has a video promoting his impressive #MPbackslap.  So why do swimmers perform these pre-race motions? 

Priming the Tissues

Athletes from all sports have their signature warm-up movements. These movements are specific to the sport, but general in their functional intention. For swimmers, the specific purpose of the backslap is to activate the shoulder and core muscles in a quick, explosive, and springy nature. Generally, the functional intention is to prime the tissues in a similar fashion to how they need to work during the race.

​Slapping the arms around the body wakes up all the muscles from the powerful Latissimus dorsi muscle down to the tips of the fingers. The vibration of the slap jump starts the nervous system and sends blood flow and oxygen to the arms. Additionally, the backslap is a plyometric movement for the upper body. The quick stretch and release primes the upper body's connective tissues, such as the tendons. Similar to how a track and field sprinter jumps in place before a 100-yard dash, a swimmer performs the backslap to mobilize their tissues and find their tempo before hopping off the block.

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Take Home Advice

It is well-established that the best way to warm-up is to perform the same motions required during the training session, but at a lesser intensity. This allows the nervous system, endocrine system, and other vital organ systems to initiate all the proper mechanisms without getting injured.

For example, during a warm-up the sympathetic nervous system turns on, blood vessels dilate to bring oxygen to the body, and specific hormones are released to prepare the body for more vigorous activity. The backslap and a few other full range of motion dynamic stretches accomplish all the necessary components to prepare the body for maximal effort! 

Listen to Your Body

Many factors play into a successful warm-up, but the most important is listening to how your body feels.

• If you feel sore during a warm-up, you likely need a few extra minutes to help ramp up your system for exercise.
  
• If specific movements feel restricted, spend extra time opening up those movements so your range of motion and strength is available.
  
• Lastly, try to enjoy the warm-up! Most people do not leave enough time to warm-up; and therefore, it becomes burdensome. If you consciously make time and enjoy the warm-up, your mind and body will be much more prepared for the task at hand! 

-Jim Heafner PT, DPT, OCS
Owner, Heafner Health Physical Therapy