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Shapes and Skills Part II

In part I, we introduced the concept that skills are directly by the inherent structures that swimmers possess. As some of these structures are unmalleable, swimmers are going to possess certain innate movement tendencies. In part I, we discussed many of the unchangeable factors that influence skill. The point was to help coaches understand what can be changed and what cannot be changed, and how this influences the skill acquisition process.

Different swimmers will have different rhythms and styles, and while they might not be traditional, they may be the best solution for the swimmer. We need to be cautious when changing these attributes as we may be working against swimmers’ innate tendencies. This is almost always a mistake.

Fortunately, many aspects of innate structure can be influenced by training or nutritional interventions. In this article, we’ll take a look at what those factors are and what we can do about it.

The Modifiable

While many movement possibilities are dictated by structure, the function of joints and muscles can certainly be modified. It’s called training.

While the limits of movement, either range of motion or speed and strength, are limited by structured, the ability to approach these limits is modifiable. These modifications occur through changes in the structure of muscles and tendons, and as importantly, the ability of the nervous system to learn to access these aspects of movement. The changes are the result of training efforts directed at specific goals.

By modifying the movement options that swimmers possess, we are creating new possibilities through which they can move in the pool.

Range of motion. While joint structure isn’t going to change, joint range of motion can change. These changes can provide swimmers with the opportunity to move differently. While it seems to be somewhat unclear the extent to which muscles can actually ‘lengthen’, although some evidence does exist, the body can definitely learn to allow for greater range of motion in all of its joints. This may not result in structural change, but it can result in changes in function.

Any individual who has performed any type of exercise is familiar with changes in range of motion. Strategies to effectively improve range of motion have been explored on the site previously. If swimmers are unable to perform a specific skill due to a range of motion restriction, and it’s believed to an issue separate from joint structure, coaches have the ability to facilitate changes that may allow for the desired skills to be performed.

If swimmers are struggling to perform skills or access positions, it may be a range of motion issue as opposed to a skill issue. If the underlying movement potential is not addressed, technical change won’t happen. Coaches must therefore understand when movement limitations are impacting skill expression, and then address the underlying cause.

Muscle force production. All movement requires force. For any given movement, a certain amount of force is required for that movement to occur, and that force must be delivered within a specific time period. Sometimes that time period is very long and sometimes that time period is very short. If you want a swimmer to be able to jump off the blocks with the equivalent of a 40-inch vertical jump, they need to be able to deliver a lot of force in a small amount of time. If that force expression is not within the capabilities of the body, it’s not going to happen.

It’s NOT a skill issue and working on starts won’t fix it.

Fortunately, both the ability to create more force and the ability to create it faster are trainable. How to improve force production in the context of swimming has been explored elsewhere on this site. While some skills do not require large amounts of force, significant force production is definitely required to go fast, particularly as the level of competition goes up and the event distance goes down.

As with the 40-inch vertical jump, if swimmers want to attain a certain stroke length and stroke frequency combination, the required force must be in place. As both numbers go up, more force is required. Expressed differently, the power required to overcome drag increases exponentially as velocity increases. The expressed power is going to be limited by the force production potential of associated muscles and joints.

While the required power can be reduced by better streamlining, more power is required at some point. All of the technique and skill work in the world won’t allow this power to be created if the potential is not there. It needs to be trained.

If a swimmer is continually struggling to acquire a skill or move in the way you envision possible, they may simply be lacking the strength to perform those movements effectively. The underlying cause must be addressed for progress to occur.

Flotation potential. Technically, flotation potential can be influenced by improving lung capacity. However, these adaptations are not particularly large, and they are small compared to the impact of genetics. Moreover, these adaptations tend to occur as a side effect of a reasonable training program.

Bodyfat composition, but NOT distribution, can be influenced by training. However, the adaptations that would improve floating potential, increasing bodyfat, tend to be counterproductive for other reasons. Increases in bodyfat require more weight to be moved through the water, as well as increase the surface area of the body exposed to the flow of the water, increasing drag. As neither effect is a positive, trying to improve flotation potential via increases in body fat is not a winning solution.

Bone density can also be influenced by training and nutrition. The best way to reduce bone mineral density is to reduce gravitational loading and nutrient availability. Reducing bone mineral density through these means doesn’t sound like the best strategy for health or performance. Strength training of some sort is going to be required to improve force potential (see above). Increased bone mineral density is an effect of many strength training programs, and some change is likely unavoidable. Considering that this will improve the long-term HEALTH of most swimmers, I would not consider it a cause for concern.

While you probably CAN positively impact flotation potential, I’m not sure that you SHOULD.

Fatigability. The ability to sustain skilled swimming is limited by the physiological capacity of the body. As a certain amount of force is required to perform a given movement, a certain amount of energy is needed to sustain movement. The more demanding the movement (i.e. the faster a swimmer is going), the more energy required. If the energetic potential is not there, the skills are not going to happen.

Some swimmers are better at managing their skills as they fatigue. This is a function of focus and it is a skill. It can be improved. It’s important to recognize and appreciate the difference between a lack of or inability to focus, as opposed to insufficient physical ability. While there is not a concrete way to do this, an awareness of this dynamic can help coaches appreciate and navigate the nuance over time.

If coaches expect swimmers to execute certain skills in practice, training sessions must be scaled so that the physiological demands are in line with the physiological capacities of the swimmers. If swimmers’ skills are continually breaking down during training sets, it may be a skill or focus issue. However, it very well may be that physiological capacities have been exceeded. Exceeding these capacities will lead to a break down in skill.

At this point, it is NOT a focus issue. The training is too hard. Training must then be adjusted to accommodate each swimmers’ abilities so that skills can be performed appropriately. If swimmers are consistently failing at what is asked of them, it may be that they simply can’t do it. Over time, as physiological capacity improves, training can and should be scaled upwards.

If coaches can facilitate enhanced physiological capacity with sound training, it expands the opportunity for skilled expression. If we expect swimmers to sustain longer strokes at faster tempos, there must be a corresponding change in physiology, which is part of the training process.

The training process should concurrently improve skill, focus, and physical ability in a complementary manner, with all aspects being develop harmoniously. Appreciating the links between these elements can help coaches develop programs that simultaneously develop each ability.


As you can see, physical characteristics can be modified, and these modifications can create a better platform for skill acquisition. With improved range of motion and force production, swimmers will have more (and better!) movement opportunities that they can access to swim fast. Creating this movement potential is fundamental to enhancing performance, and should be a central focus of any land-based activity.

In part III, we’ll explore how to specific use this information in the context of developing plans and deciding how to intervene improve skills in a manner that will result in faster swimming.

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