Home > Swim

Should triathletes swim with fins?

Training with swim fins can be enormously beneficial to triathletes by improving strength


Training with swim fins can be enormously beneficial to triathletes by improving your swim your strength, flexibility and technique.

Fin selection
Selecting your fins is an art in itself.  Here are some simple tips to follow before you buy:

If you are new to fins or if you are going to be using them for technique improvements, buy a set with a medium blade and softer material. The medium size blade provides more surface area and therefore more lift from each kick. The softer material reduces the amount of stress applied to the ankle and foot.

If you are an experienced swimmer and have a reasonable body position, then you might be best to get short blade fins. These fins will allow you to keep a fast tempo to your kick and they don’t provide as much lift. The short blade fins come in a variety of firmnesses.

Don’t buy long bladed or vented fins. This would be the equivalent to buying a water-skiing wetsuit for open water swimming. These fins do not allow you to kick at anywhere close to a proper swimming tempo.  As well, these fins are not allowed in some public pools during length swimming.

One last option is the ‘Monofin’.  These are essentially two fins moulded together forming one huge blade.  Monofins are great for butterfly and core strength, but of little use for freestyle.  I have found that you can create your own ‘Monofin’ by putting on an ankle band and then slipping into your regular fins.

There is a huge assortment of fins out there, so take the time to consult your friends and coaches.  If you are unsure, get some good advice from a swim supply store that you trust and that has a good selection.

From a physiological stand point, swimming with fins is the best way to improve ankle flexibility, kick-specific leg strength and neuromuscular patterning.

Any swim coach will tell you that the key to fast, efficient kicking is ankle flexibility. Not just any ankle flexibility will do, however. Triathletes usually have strong ankles and have decent dorsi flexion (ability to pull toes towards shins) thanks to the biking and running they do. To kick properly, though, you need to be able to plantar flex (pull your toes under and extend the top of the foot). Kicking with fins increases the flexibility of the top of the foot and shin because the large surface of the fin catches more water, forcing the swimmer to plantar flex. The larger surface area increases the muscular load and, as a result, improves leg strength as well.

Training with fins will allow you to develop better feel for the water. Good swimmers often talk about this elusive concept. ‘Feel for the water’ is, in essence, muscle memory and neuromuscular patterning. You can develop proper neuromuscular patterning at race pace or higher speeds by swimming with fins. Fins are also a great tool to keep your feel for the water if you are suffering from an upper body injury.  If you cannot use your arms at all, hard fin workouts will keep your legs, feet, ankles and heart in great shape. I find that most people can kick with fins as fast as they can swim, so you can even join your regular swim team practice for the full workout!  If you can use your arms, but need to lessen the load on parts of the upper body, swimming with fins is an excellent way to keep in shape as you heal.

From a freestyle technique point of view the biggest benefit of fins for triathletes is an immediate improvement in body position.  A lot of triathletes tend to swim on an angle with lower back, glutes and legs trailing well below the surface of the water. Even triathletes who are good swimmers will tend to have a slight angle to their position when their legs are tired from run and bike training.  By strapping on a pair of fins the lower body is brought to the surface with even a small amount of kick.

Eighty percent of the power and propulsion in freestyle comes from the arms. By bringing your lower body into the proper position, fins allow you to focus on improving your arm technique. This is especially true when doing drills that require you to swim slowly, or drills that require an efficient kick such as sculling. I have seen triathletes struggle to simply breathe and not sink while doing drills, let alone do the drill properly.  Fins allow you to execute drills properly and therefore develop the proper neuromuscular firing and muscle memory.

Workout suggestions

Here are some ideas for sets to work on the benefits discussed above: neuromuscular firing, kicking efficiency, core strength,  upper body strength and upper body technique.  Remember that whenever you are using your fins your ankle flexibility and strength will be improving – you don’t need to do any specific sets for these benefits.

Start by incorporating 200 to 300 m of fin use per week and build up to 10 per cent of your weekly swim volume.

One thing that triathletes have to watch out for, when using fins, are calf and foot cramps. It is no secret that triathletes are long time sufferers of cramps after long or hard leg workouts. Make sure that you are well hydrated – and electrolyte loaded – before using fins.

Most triathletes won’t go to the pool without their pull bouy because it helps them with their body position and eases the work done by their legs. I suggest switching to a set with fins once in a while: you may be surprised at the improvements to kicking efficiency, body position and arm technique.  Your ego may thank you too as you fly up and down the lane.

Former University of Toronto swimmer Ayesha Rollinson is a triathlon coach and retired pro triathlete from Toronto.