This post is sponsored by Garmin! Check out their new Forerunner 945 smartwatch for detailed analytics and tracking for pool and open water swims, plus tons of other fitness activities.

If you want to get faster, it’s not enough to just show up to the pool each day and train hard. You have to measure your progress! 

From total distance to stroke count, keeping an eye on data can help paint a picture of your swimming journey and helps measure how you’ve improved. Stick around to find out which metrics are most important. 

6 Most Important Swimming Metrics to Track

1. Lap Splits

Your lap splits measure how fast you went for a specific distance. These can be broken down however you see fit, but typically splits are measured at the 25, 50 and 100 in a short course pool, or 50 and 100 in a long course pool.

When you know how fast you’re swimming, you can make a game plan to get faster. 

Splits are especially helpful when you’re doing variable speed training. For example, when you’re doing 6×50 descend 1-6, you should be getting faster with each rep. You won’t know for sure if you’re properly descending if you don’t know what your splits are! 

This also applies for swimming sets at race pace. You’ll break your goal time down into smaller chunks by 25, 50 or 100 and stick to that time for each rep. For example, if you’re trying to swim the 200 freestyle in 3:00, your goal splits would be 1:30 per 100, 45 seconds per 50 and 22.5 seconds per 25.

Most smartwatches, including Garmin’s Forerunner 945, automatically track your lap splits as you swim, so you don’t have to worry about memorizing all of your times during your workout. In the MySwimPro app, you can see all of your splits broken down by set and easily track your improvement over time. 

2. Stroke Count 

Even more fundamental than splits is stroke count. When you know how many strokes you take each length, you can understand and improve your swimming efficiency. You want to find a sweet spot in your stroke in which you take as few strokes as possible while maximizing your distance per stroke. 

Related: The Swimming Equation

Of course there’s a point where you can take too few strokes — you don’t want to spend too much time gliding between strokes just for the sake of reducing your stroke count. That’s not efficient! Improving your strength and power through consistent training will help you increase your distance per stroke and reduce your stroke count. 

3. Heart Rate

Heart rate is a great measure of your effort level and general fitness. Some athletes like to use heart rate zones to guide their training. 

In this training modality, your goal is to stay within a specific heart rate zone rather than going for a specific pace or split time. Each of the 5 zones is a percentage of your maximum heart rate. To calculate your approximate max heart rate, subtract your age from 220.

  • Zone 1: 60-70% max HR (Easy swimming pace)
  • Zone 2: 70-80% max HR (Warm up or cool down)
  • Zone 3: 80-90% max HR (Endurance, think longer swims)
  • Zone 4: 90-100% max HR (Hard effort)
  • Zone 5: 100-110% max HR (All out effort, sprinting to the finish!)

It’s important to train your body in all heart rate zones to develop a well-rounded aerobic and anaerobic capacity. We should also note that heart rate is a very personal metric. You could do the same workout as someone who is older and less fit than you, and their heart rate would be very different than yours. 

The best way to track your heart rate while swimming is to wear a smartwatch! Garmin’s Forerunner 945 is a data powerhouse. It tracks not only your heart rate (using underwater-specific heart rate technology), but also your pace, stroke efficiency, calories, VO2 max, stress level and more. Plus, the watch will tell you how each workout impacts your aerobic and anaerobic fitness, and how much time you should take to recover. 

You can set up special distance and pace alerts for pool and open water swims so you don’t have to stop to check your watch during long workouts. Built in safety tracking features give you peace of mind if you’re swimming alone.

And of course, you can sync every swim workout to MySwimPro via Garmin Sync. All of that with up to 2 weeks of battery life, music capabilities and tracking for running, cycling, hiking and more, and this watch is a winner! Purchase the Garmin Forerunner 945 >

4. SWOLF Score

If you really want to analyze your swimming efficiency, take a look at your SWOLF Score! 

To calculate your SWOLF Score, add your split time and stroke count together. For example, if you swam 25 meters in 20 seconds, your SWOLF Score would be 35. If you’re able to stick to the same splits (or faster!) and/or take fewer strokes, you’ll know that your swimming efficiency has improved.

Related: What is SWOLF?

Your SWOLF Score will vary depending on the stroke you’re swimming. Don’t try to compare your SWOLF for freestyle and breaststroke — the strokes are too different!

When calculating your SWOLF Score, make sure to normalize the number to a 25-meter pool, as SWOLF is always based on 25 meters. If you’d prefer not to do your SWOLF calculations yourself, check out the MySwimPro app! Our advanced analytics include SWOLF score for every workout.

5. Total Distance

While it’s great to set a distance goal for yourself, trying to swim as many yards or meters as possible isn’t necessarily going to make you faster. It’s still helpful to keep track of your total distance per workout, per stroke within each workout, and even per heart rate zone.

Related: I Swam Every Day for 30 Days. Here’s What Happened.

For more long-term goals, you can look at your total distance for the week, month and year as well.

When you’re trying to increase your swimming distance, follow the 10% rule: Don’t increase your total distance by more than 10% each week. Doing too much too soon could result in overuse injuries and can hinder your performance. For example, if you swam 10,000 meters one week, you’d increase your distance by just 1,000 meters the following week.

6. Workout Density

Many swimmers don’t think about the density of their workouts: the amount of swimming they do per unit of time. 

For example, cramming a 1,000-meter swim into 15 minutes is very different from swimming 1,000 meters over the course of 30 minutes. In the 15-minute workout, you may swim 1,000 straight, or take just a few, very short breaks (maybe 2x500m). The 30-minute workout, however, may be broken into a series of shorter repetitions, such as 20x50m, with more rest. 

These workouts are both great in their own way, but achieve different goals. High density workouts are generally more focused on aerobic training, while low density workouts may be more focused on sprinting and speed work. 

If you exclusively do very dense workouts, you could end up injured if you don’t give your body a break. Keep an eye on your workout density each week so you know when to back off!

Remember: What gets measured gets improved! Which swimming metric is most important to you? Share in the comments! Try tracking your swims with the Garmin 945 smartwatch. Check it out here >



  1. Too technical and competitive for me. I’m looking to improve my strokes aand was hoping you would touch on this. I’m a senior citizen who loves to swim but In self taught and want to make sure my strokes are correct

  2. 220-age is a very poor measure of max heart rates. Max heart rates will vary by individual. The best way to find Max HR is to do a test. There are several around where your bike or run, or row a specific set of exercises.These also lead to good Vo2Max numbers.
    A better formula for a guide is 211-(0.64) Age. For example, a 50 year old using 220- age, would have a MaxHR of 170. 211-(0.64) Age = 179 Max HR.

  3. I, too, am a senior. I began swimming 5 yrs ago and bought a Garmin watch initially to track my laps. Pre-pandemic, I was able to swim a mile continuously in the pool but, it took me an hour. So, I set a new goal of 400 in 12 min which I could achieve with fins. Now, my new goal is 400 in 12 min with no enhancements (e.g. fins, paddles) using My Swim Pro Beginners Training Plan to work on efficiency. The metrics I relie on are distance, time, stroke count, calories and SWOLF now, that I know what it means [;-). Typically, it varies based on how rested I am. However, I do see improvement. Overall different strokes for different folks; some people prefer to set goals regardless of age, health, etc. Happy swimming!

  4. Geoff Ansell on

    You say the Garmin 945 tracks VO2max when swimming.
    Are you sure?
    I use a Fenix 6 and it is not a possible to measure VO2max when swimming.
    Please let me know if the 945 dies.

  5. my Swim2 has consistently overstated my heart rate when elevated. I also wear an apple watch w ekg function and it is accurate w HR and easier to watch for real time metrics. I am training in open water and wish I had one watch that serves me well.

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