Some years ago I was approached by a engineer/swimmer who was developing a clever device that you could strap to a swimmer’s waist and would act like an airplane’s gyroscope and black box, recording the movements of the vessel: changes in velocity, changes in vertical position, rotation angle from side to side and timing of all core body movements. After the swim you could take this data back to your computer and see this data represented graphically. It seemed promising, other than the fact that something had to be strapped on.

I lost track of the development of that device, but in just a few years later it seems we’re on the cusp of an  explosion of waterproof personal devices that could measure all sorts of interesting things, beyond what’s already being measured by swim watches. What’s going to be more powerful is the ability to view that data in real-time, through goggles or some holographic projection in front of the eyes in the act of swimming. The more immediate and direct the feedback, the more effective it is, assuming the athlete knows how to use that feedback. Waiting to view that data later, after the swimming is done, is not very helpful for skill learning.


Discovering What’s Going On Inside

External data regarding speed and distance is interesting and useful, but the gold mine is in discovering what the body is doing inside and how its interacting with the water. We are much better at sensing our position and movements on land. The challenge is that being horizontal and weightless in water is an awkward situation for the nervous system of a land mammal human. Our nervous system is wired for standing vertical on land, with gravity pressing us down against fairly solid surfaces. We have several non-visual systems for monitoring the body’s position and movement, but visual input remains the dominant guiding system for seeing people.

One old fashioned way of training proper body position (besides having a swim coach yell at you from the deck! LOL) is to look for any visual cues available in your lane space to sense deviations in your body position from the ideal. For example, on non-breathing freestyle strokes, while the head is set looking straight down, that fixed head acts as a reference point for the torso making it is easier to sense how far the torso has rotated relative to that head position. But when the head turns during the breathing stroke, that reference point is taken away for a moment and body parts can more easily deviate from the ideal without detection. The ancient and still quite relevant way of preventing this is to pay close attention to the sensations – internal and external – surrounding the ideal position of a particular body part relative to another and to how the flow of water feels over that part of the body on the non-breathing strokes. Then keep attention on that same part as you move through the breathing stroke and search for any changes in the feelings of your body parts, and in the feel of the flow of water. And, when the head turns back, notice if the body parts are still where you thought you left them. For example, is the lead arm still in extended straight in front of the shoulder? Is the body still positioned over the line just where it was when you started the turn to air?

Proper position and movement patterns are just some of the forms of data we’re interested in. We know there is so much more – speed, stroke length, stroke rate, drag, power output per stroke, heart rate, respiration volume and frequency, relative relaxation, energy efficiency, etc. We have such a strong drive to collect more data, and find ways to use it, and that’s not a bad thing.

Two Kinds Of Technology

In the old days, there was just you, your nervous system and the water. But now you have options of using pull buoys, fins, snorkels, paddles, gloves, drag chutes, and wearing watches, heart rate monitors, and audible beeping devices. Goggles with live data display are now on the market.

We could divide all this technology into two categories:

  1. Technology that stimulates human sensory and motor capabilities, making them stronger.
  2. Technology that replaces human sensory and motor capabilities, making them weaker.

Make You Stronger

Some kinds of technology force the brain to pay closer attention, to increase its strength of perception and control. They limit the options available or call attention to less favored options so that the brain is urged to use a capability it would otherwise neglect or ignore, or form a new one. This is ordinary practice among physical and neural therapists who have been, for decades, using technology to train the brain to accomplish a chosen task in a new way, and get stronger at it.

A trainer or therapist might make a client do one leg squats with that supporting foot on an unstable surface, like a balance board or barefoot on a soft pad. This kind of technology forces the brain to get better at sensing and maintaining balance on a single leg under more-difficult-than-normal conditions. After repeated stimulus, remove the technology and the person is even better at holding balance on a single leg on a more normal, stable surface. The technology was used to increase their capabilities and then it is removed.

For swimmers, there is a simple low-tech piece of gear called a ‘fistglove‘ that you put over the hand closed in a fist that allows it to hold that shape passively (you don’t have to squeeze the fingers together). This reduces the surface area of the hand and it blunts the sensory information coming from the nerve receptors on the surface of the hand’s skin. The brain is forced to search for a grip on the water with less dependency on the hand, which naturally urges the brain to use more of the forearm to get that grip. This is the ultimate anti-paddle and, contrary to popular practice, arguably far more effective at helping a swimmer develop a more skillful catch. Swim a while with fistgloves then take them off and your grip on the water feels enormous, because your arm’s sensitivity to water’s pressure has been enhanced.

Make You Weaker

Then there are some kinds of technology that allow the brain to let go of its responsibility to pay attention, which can weaken the body’s capabilities, if that tech is depended on frequently.

A therapist gave me one example from her realm: A brain-injured patient may have lost the ability to lift the toes on one foot and keep those toes from catching as they walk, yet they can move the ankle somewhat in other directions. This lack of dorsiflexion ability poses a serious tripping hazard. They might be given an ankle brace to wear all the time which would help hold the toes up and greatly reduce their risk of tripping. But that brace also prevents the ankle from exercising, and possibly expanding its range of motion and strength through regular exercise. It prevents the opportunity for the brain to build new compensatory skills. The device is useful, but it also has liabilities. It needs to be prescribed with care so that it helps in the way intended while not causing new problems for the patient or hindering their rehabilitation in other ways. The patient needs to be instructed as to when to use it and how, and when not to use it.

In swimming, there are so many examples of ways in which people are using technology to try to help their stroke or strength in one way, while possibly injuring their capabilities in another. There are bio-mechanical concerns, for which pull buoys, paddles and kick boards present some of the greatest liabilities, despite the good intentions behind using them. There are neural concerns about the popular use of swim watches tracking data that the swimmer could be training their own brain to sense and monitor in the midst of their action so that it actually serves them right then and there.


Let Them Cause No Harm

I am reluctant to criticize certain devices out there on the market (with the exception of pull buoys, paddles and kick boards) because I believe the inventors to be smart and sincere, and I think many devices could be used in a sensory or skill-strengthening way, and minimize the risk of new problems. It’s just that I don’t think most people, without strict guidance, are actually using them this way. The unskilled use of these devices give an illusion of productivity. Many dedicated athletes who buy swim training devices and use them on their own are not being trained in proper use the way a patient would have a training device recommended to him by his therapist for a specific need and then trained in precisely when and how to use it in order to get the intended benefit and avoid the inherent liabilities of each. Therapists I know have great professional caution about the potential for training aids to cause harm and are careful to instruct their patients in proper use. But I am afraid this caution is all-too-often missing in swim coaches and self-coaching swimmers because they don’t understand the liabilities.

It is unfortunate to see people using some technology devices, it seems, as a way to reduce own skill-building efforts, even making excuses for tuning out, while hoping the device magically makes their perception and control more capable without actually being required to exercise those. You can’t hack the swim code until you put in the time and effort to train your brain for superior perception and control. Some devices, used properly will force you to do that work, while others, or good ones used improperly, will hinder you.

This discussion is continued in Part 2, and I leave you with these Guidelines for Using Swim Training Devices.


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