How to Choose Fins

Welcome! If you’re looking for information about swimming fins, you’ve come to the right place. First things first. What are swim fins and how do they differ from dive/snorkel fins? While they seem similar, not all Swim Fins are created equal.

Cressi Pluma Snorkel Fins

Fins with long blades are better suited to diving and snorkeling due to their ability to produce major propulsion with minimal effort.

Swim Fins are used for swim training (to help you become a better competitive swimmer), and to add resistance to your kick which helps build muscle while swimming. They are most commonly used in a swimming pool. And while you could use them when swimming or training in the ocean, these are not the same thing as “dive fins” or “SCUBA fins” which are used, you guessed it, for SCUBA diving or snorkeling.

There are many differences between the two, but the defining factor is that dive fins feature a longer blade, and are designed for a slow, broad kick, used to overcome the drag imposed by dive equipment. (Divers typically don’t swim using their hands).

Aqua Sphere Micro Fins

The short blade design of a training fin is ideal for a quick kick tempo, along with leg strengthening.

Swim fins on the other hand (see picture above) have a much shorter blade, which help to build muscle by adding resistance to your kick as well as many other benefits discussed below.

The Benefits of Swim Fins

We know that swim fins increase the surface area of the foot, providing added propulsion and increased speed while swimming. But how does this actually help you become a better swimmer?

For Strength Training

It may not be obvious at first, but when you’re using fins to swim faster, your legs are actually working harder than they normally would (without fins) to maintain that speed. Over time, your leg muscles become stronger which will ultimately allow you to swim faster and longer when you’re not using fins.
But if the goal is to make your legs stronger, why not just swim faster without fins? Well, you could probably kick twice as fast for about one lap, but you’d quickly find yourself out of breath and out of energy.

Many swimmers rely on the extra resistance provided by swim fins to achieve a strength and cardio workout. Why? Because kicking fast, but finless puts extra strain on your heart muscle, but doesn’t help your legs get any stronger since you can’t maintain that pace for a long enough time. Additionally, even though your heart rate will be elevated, it will most likely be elevated way beyond the upper limits of your target heart rate, which will quickly result in fatigue. So really fast kicking is no good for a cardio workout either.

Just like with traditional strength training, you should push the limits of your muscles to improve them, but you don’t want to over-work them, or attempt too many repetitions of the same muscle group without taking time off to rest. By using swim fins, you can work your legs harder without overloading your muscles.


Using Swim Fins for CardioVascular Exercise

Before we talk about the role swim fins play in a cardio workout, we need to talk about some exercise theory.

First, What is Cardio?

Using swim fins can increase cardiovascular health significantly. Cardio is a short term for ‘cardiovascular exercise’. The Latin prefix ‘card’ meaning of or having to do with the heart. So in short, cardio is nothing more than strength training for your heart muscle. Swimming with fins is just one of the many ways to get a good cardio workout. You could just as easily run, jog or jump rope. (But swimming is much more fun!) We’ll discuss swimming for cardio in just a moment.

Speedo Biofuse Fins

In order to give your heart a good workout, your heart needs to be in it’s target heart-rate range for an extended period of time- usually between 20 and 30 minutes, and you need to be utilizing a large portion of your body’s total muscle mass. For an intense cardio workout, you also need to use both your arms and legs simultaneously.

Why Do Cardio At All?

The biggest benefit of regular cardio work is a stronger heart. The stronger your heart, the longer you can swim- or perform any other activity for that matter. In other words, the direct benefit of a strong heart is increased endurance. If your heart can supply blood (and thus oxygen) to your muscles more efficiently and for longer periods of time, your entire body will be able to perform better in physical situations which will, in turn, increase strength and stamina.

Target Aquatic Heart Rate

Your heart-rate while swimming or doing water aerobics will be much lower than it is on land, even though you are still receiving the same exercise benefits you would on land. If you’re swimming for cardio, you’ll first need to calculate your water target heart-rate. Remember- it’s NOT the same target heart-rate you’d use for running or jogging. A 13% reduction from your target land heart rate will yield an accurate aquatic target heart rate.

So What Does This Have to Do With Fins?

Here’s the problem. As mentioned earlier, in order to get a proper cardiovascular workout, you need to use a large portion of your body’s total muscle mass when exercising. Over 60% of your body’s total muscle mass is in your legs, so any proper cardio workout must involve heavy use of your legs. When running or jogging, this is easy. You’re already using your legs heavily, so a little bit of arm movement is all you need to maintain your elevated target heart-rate (which is key to a good cardio workout).

When you swim, however, your arms are used heavily for propulsion and the legs are often neglected. Sure, you’re kicking with them, but you’re working your arms far harder than your legs, and this isn’t very good from a cardio standpoint- you want to be using your whole body equally. The thing is, human legs weren’t designed for swimming. They’re extremely inefficient at it. The foot has very little surface area and just isn’t that great at propulsion.

So how can we make our legs work harder and still have enough energy for a solid 20 minute workout? I’m sure you’ve already guessed where I’m going with this: Swim Fins! The title of the site.

Wearing fins does more than make you look funny. They increase the resistance of your kick by adding surface area to your foot. The more resistance, the tougher the workout. And the tougher your legs work the harder your heart works. And it’s this elevated heart rate that, just like exercising any other muscle, makes your heart stronger.

Looking for a change of pace? You can also get a good cardio workout by treading water in fins, and tone your legs nicely while you’re at it!

Cardio For Weight Loss

Weight loss has been directly linked to an elevated heart rate. Although losing weight and burning calories is actually the result of higher levels of oxygen consumption, the heart is responsible for delivering that oxygen throughout your body.

When your muscles demand more oxygen (because you’re swimming, exercising, or running from a man in a hockey mask with a chain saw), your heart rate increases to meet the demand. Since it’s much easier to measure your heart rate than it is to measure your oxygen consumption, we’ll use heart-rate as an indicator of calories burned, even though oxygen usage is technically correct.

As explained above, using fins lets you exercise more muscle mass at a higher level for longer periods of time. And the more muscle mass you work, the more oxygen you use, and the more calories you burn. In short, you burn more calories because you’re able to work harder, with less fatigue.

As a bonus for those trying to slim down, calorie consumption doesn’t end when your workout does- you burn additional calories during the recovery period as well since your metabolism is still elevated for several hours afterwards. You also burn more calories simply by having muscle. Muscles burn calories even when your body is at rest- so once you build them, they’ll continue helping you lose weight for the rest of your life.

For Stroke & Technique Improvement

Many fins are positively buoyant. In other words, they float. That means that when you swim with them, the fins will keep your legs higher in the water encouraging a higher overall body position making you a more proficient swimmer.

We know that the increased surface area of the fin provides extra power to each kick making your legs more efficient at propulsion. But swimming with fins also forces your foot to extend and flex beyond it’s normal range of motion which, over time, will increase the flexibility of your feet and ankles. This increased range of motion will ultimately lead to additional propulsion and a more efficient kick without fins.

DMC Elite Training Fins

For Race Training

Fins allow you to train at race speeds without fatigue. This is important because at faster speeds, your kick is different, your arms spin faster and your body sits at a higher position in the water than during non-race swims.

Using Your Fins

The faster your kick and/or the broader your kick, the more drag is created. When swimming with fins you want shorter, faster kicks (14-18″ works best) to reduce drag. At slow speeds larger kicks the faster you go, the harder the work.

Choosing the Right Fins

Types of Foot Pockets

The foot pocket (the part of the fin where your foot goes) usually comes in two styles: an open heel design, using a strap, and a closed heel that encompass the whole foot, like a shoe would.

The closed-heel design is not adjustable, so they are typically offered in a wide variety of sizes, usually one per shoe size. The closed heel fin design also provides a snugger fit.

The open heel design usually (but not always) has an adjustable strap that can accommodate many different foot sizes. This style of in is offered in a basic small, medium, large, rather than by shoe size.

While an adjustable strap offers convenience in that it is often easier to put on and take off (the straps usually un-clip or unbuckle), a closed heel transfers more power from each kick into the fin, since there is less play between your foot and the fin.

There are a few exceptions such as Alpha Fins which have a strap on design that’s not removable or adjustable. The easy on-off is a trade-off for a less precise fit.

Proper Fit

A good fit will feel snug, but comfortable without being too tight. You don’t want to cut off your circulation, but the tighter the fit, the more power transfers from your kick to the fin. Loose fitting fins are inefficient and will waste your energy.

Closed-heel swim fins typically fit the same as your shoe size, although some brands like the Speedo Biofuse Fins run slightly smaller. If you’re right on the edge between sizes, you should probably go one size larger just to be sure. If the fin slips a little, you can easily add a pair of thin socks to take up the extra space.
Finis makes a good fin sock (called “skin socks”) made of swim suit fabric. Or if you prefer, you can also just use a pair of regular socks. You may also want to try a cheap pair of dress socks, if there’s just a small space you’re trying to fill.

Finis Skin Socks

Socks will also help prevent chaffing and blisters while providing comfort – especially with some of the stiffer swim fins.  You will also have some protection from things on the pool deck and the locker room floor.

If you choose to use fins without socks (which I prefer, but you’ll need to experiment and find out what works best for you), you may get blisters when first starting out. A lubricant such as ‘snow-seal’ boot water proofer will help reduce chafing until your feet get used to the fins. Usually after a couple weeks of swimming with fins, your feet will toughen up and the blistering will stop. Just take it slow.

It’s best to try on fins in your local swim shop, or order from an online store with a good exchange/return policy. (I can recommend a few good places to buy online, just drop me a note.)

Fin Materials

Fins are made from a variety of materials including rubbers, plastics, and foams. Fins can be anywhere from soft and highly flexible to extremely rigid and firm. Firmer fins provide more resistance than more flexible ones. The firmer the fin, the tougher the workout. If you’re just starting our with fins you’ll want to start out with a more flexible blade. The firmer fins should only be used after you work up to them. Think of it like weight lifting- when you first start, you want to challenge yourself, but you don’t want to take on too much at once.

Where to Buy

Some people have emailed me asking for recommendations on where to buy their fins. Your local Swim Shop is a great place to get swim fins if you’re lucky enough to have one in your town. Brick and mortar Swim Shops aren’t very common though, and dive shops don’t usually carry the kind of fins you’ll need for proper swim training. Personally, I like to get all of my Swimming Equipment from AquaGear Swim Shop, one of the best online swim stores in my opinion. They are always extremely helpful on the phone, and I usually get my order in two or three days with their standard shipping. Check out their Swim Fin Section to see the models they have available.

Caring for Your Fins

Swim fins aren’t too expensive, but since they’re easy to care for, why not protect your investment?

The easiest way to prolong the life of your fins is to give them a quick rinse with fresh water after swimming. Whether it’s salt from the ocean or chemicals from the swimming pool, these corrosive substances can slowly eat away at your fins over time, which can cause premature failure of the materials and decreased performance. Most pools and beaches will have a fresh water tap or hose you can use. Just ask a Life Guard or facility staff member if you’re not sure. Worst case scenario, you can rinse them in a shower since public facilities almost always provide them.

Family Carries Fins on Beach

It’s also important to avoid walking in your swim fins. This includes on the pool deck, or on the pool bottom. The most obvious reason is the rough surface will scratch them. But walking in your fins can also permanently deform their shape. Swim fins were designed for, as the name implies, swimming! They may have subtle curves to their underside that aid in propulsion, but when you walk in them on a flat deck or pool bottom, your weight causes those special curves to flatten. This flattening can not only decrease your fin’s efficiency, but can also add drag to your workout! And that’s a bad thing. (Read the section on how fins work for more details.)

To avoid causing damage, you should always carry your fins to the pool side, and put them on while sitting on the edge of the pool, just before starting your swim. Make sure that when you rest between laps (and if you’re using fins you should be resting between laps, see above!), that you’re not standing on the bottom if the lane is shallow.

After swimming, your fins should be stored in a cool, dry location. Be sure to store them our of direct sunlight, as UV rays can cause them to break down prematurely.

Side Note: Sometimes fins are used on land as part of a therapy program (for helping people learn to walk again after an injury or accident). Of course this is OK because the fins they use will never be used for swimming.


  1. I had a great set of fins with a stiff split blade, an adjustable strap to tighten and opening for the toes. Over time the rubber ripped. I love these fins but I can’t find them anywhere. Are these still made? Where can I order them? Any help will be appreciated

    1. Dennis,
      Thanks for your question. It sounds like you had a pair of the Aqua Sphere Zip Fins which featured a black rubber foot pocket with open toe area, an adjustable neoprene heel strap, and a split blade referred to as “Nature’s Wing” technology. These fins were discontinued a year or so ago and have been recently re-designed and re-marketed as the Zip VX Fins. They now utilize a diamond cut-out to stabilize the fin laterally, rather than the split blade that your old pair had. The heel strap and foot pocket are still the same design. You can check out the Zip VX Fins here:
      Hope this helps!

  2. Great article. What is difference between the long and short fins. My son’s coach has asked that he get short fins in addition to his long and mono. Thanks!

    1. Hi, Mimi. Thanks for your question. Sorry it took so long to get back to you.

      Long and short fins each serve unique purposes. While a longer blade means slower kicking, it also means building more leg strength thanks to the greater surface area and thus, greater resistance. A shorter blade fin will allow for kicking practice closer to race tempo, meaning your son will be building muscle memory and increasing fast-twitch muscle. Short fins are the standard practice fin for competitive swimmers of all ages as they are the only design that allows for fast kicking while simultaneously correcting foot position and improving ankle flexibility.

      Let me know if you have any further questions, Mimi!

  3. I have lost my Zoggs and cant find a replacement. They were very light weight composite split toe design that were a training fin but were outstanding bodysurfing fins as you can side kick for take off. Anyone know where they have gone. Nothing from Zoggs but that’s normal.

    1. Hey, Ross. Thanks for writing in.

      You’re right – Zoggs has been scaling back a lot lately. I’m not sure that they’ll be producing anything new anytime soon. As for a replacement, there used to be a split-blade design by Aqua Sphere, known as the Zip Fin. The split-blade was a trademark called “Nature’s Wing” and Aqua Sphere no longer has the rights to the particular design. They revamped the Zip fin (now called the Zip VX) with a diamond cut-out, rather than a split blade. The cut-out still stabilizes the fin laterally, but uses AS’s own proprietary design. These are super-popular with body surfers as they’re nice and short and feature a padded, adjustable open heel strap. You can check them out here:

      Hope this helps! Happy to answer any further questions you may have.

    1. Hi, Chuck. The blue Zoomers were super popular and very well-made. Finis has since taken over production of the Zoomers fins and are now available in yellow (or, “Gold” as Finis calls them). The material is reportedly softer to the touch, but more rigid against the water – offering greater resistance. I would recommend the Zoomers Gold again, as they’re really ideal for any age. If you prefer something with an adjustable heel strap, I would highly recommend the Aqua Sphere Zip VX Fins which stabilize the leg laterally to reduce torque on the knees.
      Aqua Sphere Zip VX Fins:
      Finis Zoomers Gold:

  4. I have really wide feet and want to buy training fins. My exactly measures are size 11 M EEEE.

    I just bought fins and I couldn’t even get my foot in there.

    1. David,

      Ah – that can be a difficult issue. I’m not sure on the *exact* measurements, but I know that DMC brand fins tend to run pretty wide. You can call in to this swim shop at the link below and they’ll happily measure the foot pocket for you. The DMC Elites have an open heel which may provide more give/more space for your feet’s width:

  5. As a very inexperienced adult swimmer who only recently learnt how to swim correctly, would really love to be able to swim laps without embarrassing myself in the slow lane and holding up fellow swimmers. Using fins has been recommended. Wish tgey could recommend which type would be the best for me!!! Any suggestions?
    BTW….am really really unfit 😕😉

    1. Nimamipe,

      Thanks for your question. If you’re swimming laps, you’ll definitely want a short bladed fin which will allow you to kick at a regular tempo but will propel you much quicker due to the expanded foot surface area. Try the Aqua Sphere Zip VX Fins which stabilize the leg laterally (reducing knee strain) and have an adjustable heel strap for an easier fit:

      Let me know if you have any other concerns!

    1. Ayob,

      Sometimes, a pair of fin socks (thin, neoprene socks) will do the trick, although some swimmers simply wear a standard pair of cotton socks. If your fins still slip along the sides, I’d recommend trying an alternate fin with a slimmer heel or a design with an adjustable heel strap, rather than a full, molded heel.

    1. Hi, Maria. May I ask which fins you might be interested in some further information on? Did you have a question about which type would work best for your purposes? Hope to hear from you!

  6. hi ive just seen DMCs newest swim training fin called Warrior. It looks very similar to the elite model they do. Can you brief on the difference – if any? They certainly look way cool.

    1. Barry – thanks for your question. I haven’t had the opportunity to try the Warriors yet, but they do like strikingly similar to the Elites and the former DMC “Swim Fins”. The rails along the side and the channels on the bottom look the same as the Elites. From what I can see of the writing on the package shown on the DMC site, the Warriors might feature a stiffer material and use a new molding process? Other than that, I can’t see the real difference other than gaining more propulsion from the greater stiffness (though the Elites are pretty stiff to begin with). The coor is quite a draw though. Pretty badass.

  7. Im 51 , I never used fins before . Im having trouble doing the back kick while using a kickboard . My fins are Medium blades. Please give me tips, on how to kick while using a kickboard. Gracias

    1. Paulina,

      I understand. Kicking on the back with fins can make you feel like you’re doing a backbend as your legs are drawn downward with each down kick (and the upkick is harder, so they sink further). I think that you might start by downsizing the blade size (or kick without fins altogether for a while).

      Swimming on the back, you may not even need a kickboard. If you’re using it for flotation help, try hugging the board rather than holding it above the head. This will lift the hips and help keep your kick in line with your body, rather than below you.

      Let me know if this helps! Happy to suggest some alternative methods/fins if you need.

  8. Hi
    I’m 52 and in my younger years I was a swimmer …recreationally and competitive. I have a moderate to advanced fitness level but need to lose weight (50+ pounds). I had a double knee replacement a year ago and am falling in love with swimming again and this “Finning” class where fins and kkckboards are used. Swimming is so great on my joints and I feel like I’m getting some good cardio. I would love to do a finning workout on my own for all the benefits you outline in this article. I went on Aqua Gear but I’m not certain what fins to start out with for maximum cardio benefit for weight loss. And/or should I buy that streamlined kick board too ? Any advice you can give would be appreciated. Thank You!

    1. Hi there, Carol. Thanks for writing in. I would say that any short blade fins will deliver the kind of cardio results you’re looking for. As you probably remember, long fins will give you lots of propulsion, but will slow your kick (meaning you won’t reach peak cardio levels). I’d look at the Zoomers Gold or Zoomers Fit by Finis – favorites among fitness swimmers. They both feature a very short blade which is ideal for a quick kicking tempo. You might also want to check out the Aqua Sphere Zip VX Fins which have a channel that funnels water through the center of the fin. Because of this channeling, the fin is stabilized laterally – easier on the knees and hip joints.

  9. I am 70 years old. I just started going to the rec center pool to swim. I am interested in the shorter fins to swim and increase my cardio strength. I am a 7 1/2 shoe size but have a narrow heel. I am not interested in racing, as you can imagine. I just wanted to improve my leg strength. Any suggestions on the type of fins and where I should look for them on-line?

    1. Hello, Susie. No problem at all! For a smaller-heeled foot, I think that the Finis brand would be a good option as their foot pockets do run a bit on the smaller side. Their Zoomers Gold and Z2’s are good options for fitness. The Zoomers Gold are also made from natural rubber, so they’ll do a better job of conforming to the foot over time, whereas a silicone fin will rigidly hold it’s shape over time. As an alternative, a fin with an adjustable heel strap may be a good choice as you can tighten it down to size. Not many training fins have a heel strap, but the Aqua Sphere Zip VX Fins and the Finis Positive Drive Fins do have this option. The Positive Drives have a uniquely round blade which is best if you are swimming more than just the freestyle – they’re designed to accommodate all 4 strokes, including breast stroke.

      You can find any of these fins on this website:

  10. I have searched everywhere and cannot figure out if the finis zoomers fit have a left and a right? Or are all find universal left and/or right footed? Sorry for my ignorance, I just got a pair for cardio training and such in my pool.

    1. Good question, Jak. The Zoomers do NOT have designated left and right foot pockets. They can be worn on either foot. In my experience, very few fins come with left and right. Some, like DMC fins, are mirror images and must be worn on the correct foot (or you’ll notice quickly that they’re on wrong).

  11. I am 51yrs old and began swimming about 8 months ago. I find that unless I use a pull buoy my legs drop while swimming. Can you recommend a pair of fins to help with my training? I have recently found I can use my arms etc with the pull buoy, but once I go back to training without it my legs drop after a few yards.

    1. Hey, Steve. You’re facing a pretty common problem here. Foam fins can be really helpful to add some buoyancy to the legs and (hopefully) eliminate the need for a pull buoy. Try the Aqua Sphere Alpha Fins which are made from buoyant EVA foam. Also, as you’re swimming, try to imagine swimming slightly downhill. This will align your head into streamline, which automatically buoys the hips and legs, just like a teeter-totter.

  12. just wondering have had an older pair of churchill originals from the early 70s – longer length but very flexible blade. bought churchill slashers with shorter blade but much stiffer. I use them mostly for body boarding in san diego. the slashers tire my legs out way too much and seek a replacement for them but would like a shorter blade than the originals, a blade like the slashers but with the original flexibility…. any suggestions?

    1. Hi, Dusty. I can’t say that I am too familiar with Churchill fins, but I hear a great deal of positive feedback on them. The blade stiffness is difficult for me to know since I’ve never tried a pair myself. As for the design, I’ll say that the DMC Elite Fins are very similar in blade length and are designed for body surfers/boarders. The Elite’s are made from a soft silicone so the blade is stiff enough to provide great propulsion but I wouldn’t call them “rigid.” The side rails are meant to assist in propulsion, while the designated left and right designs keep the fins from catching on each other. Most swim shops will allow you to try the fins (without damaging them, of course) and return them if you don’t like them. Let me know if you have further questions, Dusty.

  13. Hi! I just recently started swimming to have some exercise (I live in the Philippines and hate gyms). What fins do you suggest I try out? Noticed that my arms burn after swimming but my legs are just fine. I’ll be going to Hawaii in a few weeks and I’m thinking of getting my fins there since I’m sure they’ll have more options than we do in Manila. Thanks!

    1. Thanks for writing in, Jing. It makes sense that your arms are sore because most of the work of swimming is done with the upper body. You’ve probably noticed that professional swimmers have huge shoulders (for this very reason). Wearing a pair of short-blade fins will allow you to maintain a quick kicking tempo while adding surface area to the foot (then, you’ll feel the burn!). I wear the Finis Zoomers Gold for a daily workout, but they’re really only suitable for the flutter kick:

      If you’re planning to swim the breaststroke, I’d recommend the Finis PDF Fins which will allow you to do a whip kick:

  14. Hi! Can you recommend fins for kids learning to swim – to help adjust foot position, etc. One of my concerns is how fast their feet grow & the frequent need to replace them. Is there an adjustable?

    1. Good question, Cecilia. Nearly any short blade fin will work for a child just learning to swim. Their foot position will adjust pretty quickly and naturally since fins don’t propel you when your form is incorrect. For example, kids who bend their knees a lot (bicycle-kick) and kids who lift their legs high out of the water will quickly realize that these motions aren’t moving them at all and settle into proper form without much interference/explanation from an instructor. Depending on the child’s age, you have a couple of options. Water Gear makes a super-simple fin with an adjustable strap, but they’re only recommended for kids aged 2-5:

      If the child is older, the Finis Kid Finz are a nice, inexpensive choice with an adjustable strap:
      Beyond that, you’ll start getting into more serious “training” fins for kids which typically feature a closed-heel design.

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