Swim mechanics is an area where athletes are subjected to a whole host of opinions, and determining which are valid can be tough. Having performed underwater video analysis on hundreds of athletes, the great majority of them 50 to 85 minute Ironman swimmers, I feel very confident in identifying even the subtlest of issues. Similar to my recent article on run mechanics, this is geared towards highlighting the most common and critical items related to swim mechanics within triathlon.

When it comes to mechanics and form, swimming is the most difficult and critical to master of the three triathlon disciplines. Swimming has infinitely many degrees of freedom, as compared to running and cycling, because of a lack of sturdy connections to firm ground. As an activity’s number of degrees of freedom increase, so too does the difficulty to master its mechanics.

Make sure that the swim advice you seek matches your specific objectives.

While running, you typically have one foot in contact with the ground at all times, providing one less degree of freedom than swimming. Cycling, on the other hand, allows constant contact with the saddle, both hands, and both feet, accounting for five fewer degrees of freedom than swimming. As difficult as it is to master the mechanics of running, it is exponentially so in swimming, where there are really no solid contact points.

Much of the confusion athletes feel with regards to swim mechanics is born from pool-trained swimmers or coaches, which focus on a longer glide phase and lower stroke count. Open water swimming in choppy waters requires a strong back end of the stroke, with a follow-through that pushes beyond the hips. Athletes who have a long glide phase in their stroke tend to be slowed by open water chop while in this portion of the stroke, being re-propelled with each pull phase. Unfortunately, a long glide phase typically results in a slow turnover and, therefore, fewer pull phases per minute. This mean fewer opportunities for forward motion because of not being re-propelled through the water. Because of this, open-water swims require a higher turnover than their pool-based counterparts.  

The above can be evidenced by collegiate pool swimmers who see a major de-couple, relatively speaking, between their pool and open water swim times. Although their graceful glide and strong front-end propulsion results in fast and efficient pool swimming, once offered to the unrelenting chop of the open water, these attributes are quickly minimized. This can be especially frustrating for those who race at the professional level and come from a swimming background—used to crushing their competition in the pool. With mass starts and people all around, the front end is the first part of the swim stroke to get lost in the flurry. With bodies occupying the space where a long and gliding swim stroke might occur, it becomes nearly impossible to get a strong catch and pull within the front quadrant of the stroke. This leaves the mid to back end of the stroke as the critical piece for maintaining any forward momentum.  Since the back end of the stroke and follow-through are protected, no matter how crowded the swim is, it only makes sense to apply a strong focus of our attention here.

These two points explain why pool-born swimmers may have difficulty translating their grace and speed to the open water. It’s the front-end focused swimmers (who have a long glide, strong catch, and low turnover/cadence) who are most efficient in calm, smooth, non-crowded waters. However, this same group is often outdone in the open water by the high turnover crowd with strong back ends to their stroke.

One of the most frustrating aspects for swimmers with poor mechanics is that many spend countless hours in the pool, swimming hard, 5,000 meter workouts with masters groups, but fail to make any significant progress in their open-water swim speed. This equates to a misappropriation of the athlete’s “stress budget,” because a good deal of stress is utilized with little or no return on the investment. In a case like this, the stress spent on swimming is likely better spent cycling and/or running, where speed is less dependent upon mechanics, and gains are much more likely to directly impact race speed. As such, this athlete may be able to consider backing off on swim intensity to focus on the mechanical issues that are impeding gains in speed on race day.

So let’s discuss some of the most common issues that I see in triathletes’ swim mechanics. I’ll address these in the order of importance; the percentages indicate the approximate amount of athletes I see exhibiting the issue.

Poor Balance – 20%

This issue is indicated by hips that drop, causing the swimmer to become increasingly vertical in the water. This creates a significant amount of frontal area and hydrodynamic resistance, both of which must be overcome before the body can make any forward motion. It’s very similar to riding your TT bike down the Queen K in the upright position. This resistance is so large that it’s really not worth working on propulsion, or even fitness, until it’s addressed. A good test to determine if this is an issue for you is to swim without doing any kicking at all. If you struggle to make it through 50 yards, then you likely have some balance issues. The key to working on balance for open water swimming is to stop doing the balance drill sets once you have improved your in-water balance. These sets tend to reduce stroke cadence, increase glide, and create front-end swimming.

Missed Catch – 90%

I’d estimate that only about five percent of triathletes actually have a true catch in their stroke.  The catch creates an anchor out of your arm and hand (before engaging the lats in any significant way) to create forward propulsion. Without the catch, engaging the lats and rotating at the shoulder tends to push the water downward and body upward. This exacerbates any existing balance issues, and creates small forward propulsion. This issue can be a double whammy, because it increases resistance and decreases propulsion.

Poor Timing and/or Low Swim Cadence – 50%

Ideally, your leading arm should be leaving the front quadrant, just as the fingertips of your trailing arm are entering the water. This sort of timing creates more constant propulsion, forward momentum, and leads to an appropriate swim cadence. By swim cadence, I am referring to strokes per minute, not strokes per length. The ideal swim cadence is very dependent upon your height and swim speed. Typically, at a pace of 1:50 per 100 yards, an athlete will take between 55 and 65 strokes per minute. At a 1:20 pace, we’re looking at about 65 to 80 strokes per minute. In each of these, taller athletes should fall at the lower end of these ranges.

Upward Glide/Extension – 40%

Upon entering the water, the leading arm is extended with an upward glide. This not only increases frontal area, but it also inserts a delay into the swim stroke. This delay can allow the trailing arm to catch up to the leading arm, which creates a timing issue similar to that discussed above. This delay also reduces the number of propulsive phases per minute, and therefore reduces forward momentum in a rough open water swim.

Straight Arm Recovery – 20%  

I’ve heard many coaches say that they don’t care what their athletes’ recovery strokes look like. To be perfectly honest, neither do I, except when I see it adversely affect timing, entry, and extension. Unfortunately, this is almost always the case. A straight-armed recovery often results in a straight-armed entry, with the shoulder entering the water first, followed by the elbow, and then the hand. As a result, there is a tremendous amount of resistance created, as the arm “rolls” into the water. The time required for this type of recovery often results in the leading arm getting much further along in its stroke, much too soon. This can create a timing issue that is the exact opposite of front quadrant swimming, wasting energy, because maximum propulsion is created as the body is thrust into a flat position.

Weak Back End – 80%

This is quite specific to open water swimming versus pool swimming. A good back end of the stroke should see the wrist crack, just as the elbow becomes aligned with the body. This is done in an effort to maintain a perpendicular bearing between the palm and the body as the hand moves along the body and completes its follow through. This effectively increases the length of the “propulsive zone” during by maximizing the back end of the stroke. Many swimmers do not crack their wrist, instead pushing upwards on the water with the back of their hand, thus missing an opportunity for continued propulsion.

Crossover – 30%

Many swimmers develop a crossover at some point during their stroke. This will typically occur at either entry/extension, or during mid pull. At entry/extension the forearm is the first thing presented to the water, causing an increase in hydrodynamic resistance. This also tends to produce a zigzag effect as swimmers move through the water like a snake, again increasing frontal area and hydrodynamic resistance. When viewed from the front, entry and extension should occur directly in front of the shoulder with the index finger and thumb entering first.  The palm should then be rotated to horizontal (versus outward), creating space for the remainder of the body to rotate into.

On the other hand, a crossover at mid pull reduces the swimmer’s effective paddle area, reducing the strength of the pull. Swimmers with this issue tend to either have relatively weak shoulders, or are suffering a cognitive disconnect with the proper mechanics. At mid pull, the palm should be vertical, below the armpit, or just slightly outside of that position.

Over Rotating When Taking a Breath – 70%

Swimmers who show their entire face when taking a breath tend to over rotate their head. This is very closely related to a weak back end, as discussed above. You’ll often see the palm drive outward, searching for an anchor that the body can use to “push” off of to get that big breath. Rotation of the head should be just enough to gain that breath by biting at the air, with no more than a single goggle lens breaking the water’s surface.   

Disconnected Shoulders and Hips – 15%

While this issue tends to be less common, it certainly does rear its ugly head now and again. This often presents itself with the hips rotating well before the shoulders. This decreases the body’s ability to be well streamlined. From a side-looking view, the shoulders and hips should be connected, as if one. When the hips rotate, so too should the shoulders. When the shoulders rotate, so too should the hips.

Strength Limiters – 15%

Athletes with relatively low BMIs run the risk of being strength limited in the water from both a propulsive and mechanics standpoint. Many swimmers struggle to produce an appropriate cadence, because they lack the lat strength to pull through the water quickly enough. It can also be the case that weak shoulders will prevent the athlete from holding a good arm position at mid pull, creating the crossover effect discussed above.

Why focus on the negative? Now that we have discussed the most common and damaging swim deficiencies, let’s talk about the measures that we can take to fix them. Let me begin by sharing a couple of methods to identify stroke mechanics that may be handy when underwater video analysis is not available.

Golf Test

I like to use this as a metric to measure streamlining and body balance. The Golf Test is performed by swimming 50 yards and recording your time, in seconds, and the total number of strokes it took. The sum of these two numbers is your score. Like the sport of golf, the lower the score, the better. A score above 65 for taller athletes and above 75 for shorter athletes indicates the need for balance drill sets to improve streamlining. 

100 No Kick, 50 Kick Test

This test helps identify propulsive needs. This is carried out by swimming a 100-yard TT without kicking at all, followed two minutes later by a kick-only, 50-yard TT using a kick board. Your time for the 100 yards should then be divided by your time for the 50. If this score is outside of the 1.50-1.70 range, then you should either be working more on your kick propulsion, or your upper body propulsion (i.e., arm position, catch, pull, follow-through, etc). A ratio that is greater than 1.7 is indicative of relatively weak upper body propulsion. A ratio lower than 1.5 may point towards a weaker kick.

Once a swimmer’s particular issue is identified using the above tests, or by way of underwater video analysis, I rely heavily on the following drill sets to help compensate for swimmers’ weaknesses.

The TI (Total Immersion) Family of Drills

This series of drills mainly addresses balance and streamlining issues. For these issues, there is nothing better. Once your balance issues are fixed, however, these drills should be avoided because they tend to slow swim cadence and increase front-end glide.

If you have: Poor Balance, Straight Arm Recovery, Cross-Over, and/or Disconnected Shoulders and Hips


This drill is done by swimming 100 yards, the first 50 yards with closed fists, and the second 50-yards with open hands. This helps to improve the catch phase of your stroke, by making you very conscious of your arm and hand positions, following the fist lengths.

If you have: Missed Catch

Aerobic Paddles

This helps to improve swimming-specific strength and the catch phase. Using paddles in an aerobic manner (similar to the 50 fist/50 free drill) forces swimmers to become more aware of their hand positions through the entirety of their stroke.

If you have: Missed Catch, Weak Back End, and/or Strength Limiters

Ankle Bands

The use of ankle bands shut off a swimmer’s kick, forcing them to balance their body in order to create a more productive pull for forward motion. Forward velocity helps to create balance, and is a function of good mechanics. For this reason, this drill is very effective for most triathletes, as it addresses almost all of the deficiencies that we have already discussed.

If you have: ANY of the above issues!


Tabata intervals are a great tool for mechanics, to help improve turnover. These can be done once or twice each week by sprinting 25 yards, while focusing on high stroke turnover followed by 10 seconds, and repeated 8 to 10 times. Within a single workout, this can be done for two sets of 8 to 10 repetitions, with two minutes between each.

If you have: Poor Timing and/or Low Swim Cadence

Single Arm Swimming

Single arm swimming is the number one way to connect a swimmer’s hips to their shoulders.  This drill is done with one arm out in front, while stroking with the other arm. Once this is mastered, the arm that is not stroking can be held at the swimmer’s side.

If you have: Disconnected Shoulders and Hips

Swim Cords

Swim cord routines are an excellent way for swimmers to help ingrain good arm position, and the elusive high elbow. It is always easier to work on these items with the consistency of dry land, than in the multi-variable environment of the water. Swim cords also help to target potential strength limiters in swimmers with relatively low BMI.

If you have: Missed Catch, Weak Back End, Strength Limiters

Cognitive Thinking

Believe it or not, cognitive thought can address each of the above issues. All of the drill work in the world is useless if you’re not thinking about your swim mechanics with each and every stroke. For example, thinking “fingers tips down, wrist aligned,” early in your swim stroke can help to create a higher elbow, and faster cadence.

 If you have: ANY of the above issues

Vertical Kicking and Fin Work

Vertical kicking and fin work are great ways to improve an athlete’s kick propulsion, and focus on “hiding the kicks behind the hips.” For those with very poor kicking ability, vertical kicking in the deep end for 1:00 sets is a great way to generate more kick propulsion that originates from the hips. This can be done with a kick board in your hands, slowly moving it above your head as you progress. After three sets of 1:00 can be maintained with the board above your head, it is time to move onto a bit of swimming with the fins, which help the swimmer more effectively feel their kick.

If you have: A 100 No Kick, 50 Kick ratio that is below the 1.50 threshold.

Pull Buoy Swimming

Focused aerobic pull buoy swimming is a great way to shut off the kick, and allow you to focus on many of the upper-body related limiters, identified above. This is especially beneficial for any identifiable body rotation limiters.

If you have: ANY issue other than Poor Balance!

If you’re looking for an efficient and comfortable way to swim in training and racing, focus on the front end, a low stroke count, and long glide. If you are looking to lead the swim portion of a triathlon, focus on a strong back end and high turnover, both of which still require good balance in the water.

Different swimming objectives require different training techniques and mechanical demands. So, when receiving swim advice or looking for a coach, make sure you clarify the type of racing that you are looking to do, and make sure that the advice matches your specific objectives.


Jesse Kropelnicki is an elite/pro level triathlon coach who founded QT2 Systems, LLC; a leading provider of personal triathlon and run coaching, as well as TheCoreDiet.com a leading provider of sports nutrition. He is the triathlon coach of professional athletes Caitlin Snow, Dede Griesbauer, Ethan Brown, and Jacqui Gordon among others. His interests lie in coaching professional triathletes using quantitative training and nutrition protocols. You can track his other coaching comments/ideas via his blog at www.kropelnicki.com.