Ask Stew: How to Adapt to Swimming with Fins

Recon Marine swims with fins at Camp Lejeune.
A Marine with 2nd Reconnaissance Battalion, 2nd Marine Division conducts a 500-meter underwater swim with fins and a snorkel at the Courthouse Bay Training Tank aboard Marine Corps Base Camp Lejeune, N.C., March 19, 2015. (Lance Cpl. Preston McDonald/II Marine Expeditionary Force)

"Recently I bought a pair of Rocket fins and booties. Up until now I have been using soft fins for your workouts and I have been able to fin 1 mile under 30 minutes with soft fins. With rocket fins, however, it feels much more awkward and painful. It seems as if my arm-pulls get me more propulsion than the flutter kicks with rocket fins."

1. "Is there a specific technique to finning with rocket fins? Does the kick have to be a certain width? It seems that bigger kicks give me a stop/start movement and interrupt my momentum, but while smaller kicks give me constant movement, they still don't seem to propel me that fast."

There is no one best way to swim with fins, because we all have different kick strengths. I have found that athletes in sports like football and soccer may not be the best swimmers without fins, but when they place a pair of SCUBA fins on their legs, they are faster than most people in the class. This is because they have well-developed leg and hip strength and can use bigger kicks to build speed. Some athletes with weaker legs and hips tend to swim fast, but they kick with smaller strides at a faster pace. You have to find out what works best for you. Learn how to swim on both sides as well, because you can alter your kick as long as your top leg always extends forward on both the left and right side. Learning to swim on both sides offers a form of "rest" by changing the pull-push stride of your left and right leg.

As for arm pulls and breathing -- as pictured in the video below -- the arm pull can be used as another method of propulsion, especially if you need to rest your legs by skipping a few kicks during a long-distance swim. Many people take a slight pause from kicking while breathing and recovering the arms forward again to remain streamlined. As with any swimming, recovering your arms should remain streamlined and not impede forward motion.

2. "The fins seem to cause pain in my feet after a couple hundred yards and stiffness up the front and side muscles of my shins. Is this just a matter of conditioning and getting my feet used to wearing these fins?"

It is a matter of conditioning. When first wearing fins, you should swim only a few hundred yards and push slightly past discomfort in the ankle and shin area. Do not push too hard and for too long at first, as overuse injuries such as tendinitis in the feet and knees can flare up. This process usually takes about 10-15 swims or 2-3 weeks of swimming with fins. It is recommended that you swim 500 meters with fins and then, if they start to bother you, remove the fins and swim 500 without. Then try fins one more time until the discomfort returns. Do this for a few weeks, and you will add greater distances each time you swim.

Good luck with adding fins to your swim workouts. It takes time to get comfortable so do not feel weak if you only can swim a few hundred yards the first time you wear a "real" pair of fins.

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Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to

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