Swimmer selecting a workout on the FORM Goggles

A Guide to Understanding FORM's Effort Levels

If you're new to swimming, it can be tough to figure out when and how to make your swim workout harder or easier. But don't worry, we've got you covered! Every FORM workout is specifically designed by one of our expert coaches. Each workout includes intervals with associated effort levels, so you never second guess when to swim strong or take it easy.

We’ve put together this article to help you understand what each of our effort terms means and why they’re important. We’ll also dive into how effort relates to rest. We finish up by comparing FORM’s effort levels to some other common scales. After reading through, whether you’re new to swimming or a seasoned veteran, you’ll have a better understanding of what effort to swim throughout your workouts.


There are five different effort levels used when FORM coaches write workouts. They are defined as follows:

  • Easy: smooth and relaxed, while maintaining proper technique. This effort level is typically for recovery swimming.
  • Moderate: a slightly elevated heart rate, comfortable breathing, and is sustainable for prolonged swims.
  • Strong: an elevated heart rate with heavy breathing that is uncomfortable to sustain.
  • Fast: just below maximum heart rate and can only be maintained for a short time until muscular fatigue sets in.
  • Max: an all-out effort. Max efforts are typically short swims or integrated as short bursts within longer swims.

Using these effort levels, our coaches can put together workouts with a unique purpose. With efforts that are easy to understand and the ability to take as much rest as you want between intervals, FORM workouts are for everyone! Let’s dive into why these different levels should all be part of your routine.

Importance of different effort levels

Each effort level has different physiological benefits. Easy swimming provides an active recovery, usually after a hard set or at the end of a workout. Intervals at this effort level are essential to avoid hitting the wall mid-workout, plus a well-deserved rest. Moderate and strong efforts both push your aerobic capacity and endurance. Many of our endurance and power workouts include extended time spent at these effort levels.

The final two effort levels are fast and max. Both can only be sustained for short periods of time and require more rest—sometimes even recovery intervals. These two are maximal aerobic or anaerobic efforts, which are more prevalent in power and sprint workouts. Swimming at fast or max pace requires longer rest periods but can improve your top-end speed, average sustainable pace, and is an efficient way to get a great workout.

Relationship Between Effort Level Rest

An important thing to understand is how rest intervals relate to effort level; the higher the intensity, the more rest is needed. For instance, a 200 meter interval at a moderate effort may only require 15 seconds of rest, while the same interval at a strong effort level would be closer to 30 seconds of rest. This concept tends to get overlooked by swimmers, especially early on in a longer set, like 20x50 at a strong effort level. While the first 10 or so intervals may be fine if you cut out a bit of rest, you’ll start to fatigue faster than intended. You may feel like you’re maintaining your speed, but that feeling is from fatigue, not your actual effort level. The result is worse performance in latter intervals, both in technique and interval time. For the most enjoyable swim, aim to take rest as it’s written into every workout.

Swimmer midway through a workout

How FORM defines effort and rest

As we were developing workouts, our team had to find the best way to define our effort levels so they’re intuitive for swimmers at every level. Using terms such as lactate threshold and anaerobic capacity may be popular among athletes, but aren’t as familiar to fitness swimmers. We went through internal and external testing of terms before landing on the final definitions. The terms we chose work for swimmers at every level—regardless of fatigue, stress level, etc.

Here’s how FORM’s five effort categories look compared to other popular effort scales, such as the rate of perceived exertion or zone scale. Rate of perceived exertion is the most popular scale, generally from 1-10. With this scale, the effort terms correspond as follows:

  • Easy: 1-2
  • Moderate: 3-5
  • Strong: 6-8
  • Fast: 9
  • Max: 10

Finally, we have the seven-zone scale, popularized by Dr. Andrew Coggan in cycling. This scale is generally used while training with power data and has the following relationship to FORM’s zones:

  • Active Recovery: Easy
  • Endurance: Moderate
  • Tempo: Strong
  • Lactate Threshold: Fast
  • VO2 Max: Max
  • Anaerobic Capacity: Max
  • Neuromuscular Power: Max

Looking at all the systems, the basis for creation is generally similar; build a scale that conveys the most important information to those using it.

swimmer resting on the wallModifying Rest

Getting enough rest is essential and we understand that some swimmers may need more rest than our workouts suggest. Or you might be stretched on time, so want to cut some rest time to finish your swim faster. Your goggles will sense if you start an interval before the prescribed rest time is up, switching screens to swim mode. On the flip side, if you take additional rest, your rest time will continue to be recorded until you begin your next interval.

At the end of the day, understanding these concepts will help you make every swim enjoyable—from your recovery days to your hardest swims. We hope this article helps you better understand our effort levels and rest, plus makes your experience with FORM the best it can be.




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