This is the last in my 5-part series of TI-flavored reviews of ’swim tools’ featured in the Active Swimming newsletter article 5 Tools to Spice Up Your Swimming.
Here’s an excerpt from the piece on Fins: Fins are a great way to work your legs while improving ankle flexibility. They also help correct any cross-over kick you may have. Ankle flexibility is a key element in being able to generate propulsion from your kick and is usually a very important area to work on for newcomers, especially for runners and cyclists.
A previous Active Swimming article “Used Properly, Fins Can Be a Boost to Swim Strength, Technique” claimed that while fins have long suffered the stigma of being misunderstood as cheating tools, allowing swimmers to swim faster while requiring them to exert less energy . . . [they] actually serve to strengthen a swimmer’s legs, improve cardiovascular endurance, and teach proper stroke technique.
It’s likely that 99% of those reading these articles will accept uncritically these assertions that training with fins on will benefit your swimming first by increasing fitness, secondly by increasing strength, and to a lesser extent by improving technique.
The TI position on fins is a good deal more nuanced. We don’t categorically disagree with the proposition that there may be some potential to increase fitness and strength by training with fins. If a swimmer told me they swim purely as a workout — essentially treating the pool as a ‘low-gravity gym’ — I’d have no hesitation to encourage them to train with fins. Kick with a board and fins. Swim with fins. Kick lustily. It’ll give you good workout.
Or at least a workout. If lower-body strength is really your goal, exercising with fins is far less efficacious than doing squats, stepups, lunges, etc. in a full-gravity environment. It is however a lower-impact aerobic workout than running.
Where these prescriptions become dodgy — in fact misleading — is when they mix claims for exercise benefit with claims that fins will improve your swimming.
On this the evidence is incontrovertible:
(1) Efficiency, not fitness, is far more critical to swimming endurance; and
(2) Streamlining, not strength, is far more critical to swimming speed.
In that context, the most common way people use fins – I.E. as these articles advise – will yield far less improvement than practice that targets streamlining and/or efficiency.
This is because (i) Kicking on a board with fins imprints the least efficient form of swimming locomotion, as well as terrible body position; and (ii) Swimming with fins encourages you to overkick — another counterproductive habit to imprint.
As for the proposition that using fins will correct kicking errors, this is also incorrect. Fins only address the symptom, not the cause. The most common kicking errors are caused by poor balance — fore-aft or lateral. The proper approach is to fix the cause of the error by drills or whole-stroke with focal points which closely targets the underlying balance or stability errors.
I have used fins selectively to help an occasional student learn to integrate the kick with the whole stroke. This occurred late in the stroke development process, usually after many hours of imprinting and refining balance and stability. Further, in this application, we explicitly sought to minimize power from thigh muscles. Rather we focused on using the quads as a ‘force coupler’ linking the lower leg to an abdominal power source. When you use fins as most swimmers do — and as the two Active articles advocate — you virtually always overload the thigh muscles, creating a low-efficiency habit.
My rating: 2 out of 5.