Are you getting faster, or just working harder?

When I race, it is tempting to follow the swimmer ahead without thinking too much about what the extra effort will cost me later. Their feet are within reach, the gap is opening, and I have a decision to make. What I want to recognise is whether I can sustain that effort for the distance remaining, rather than discovering a few minutes later that I have overcommitted.

I want the swimmers I coach to develop that awareness too. A quicker time is useful information, but I also want to know how demanding it felt and what happened to their technique along the way. Looking at pace alongside perceived effort gives us a more useful way to judge progress.

Putting a number on effort

RPE means Rating of Perceived Exertion. It describes how hard exercise feels, taking account of your overall effort, including breathing and muscular work. Instead of simply saying a swim felt comfortable or difficult, you choose a number that best represents your experience.

The modified scale used in the swimming study below pairs numbers with these descriptions. Six remains a valid rating between hard and very hard, although the published table gives it no separate label.

Ten means maximal effort, rather than simply feeling tired after a long swim. The distinction matters because a long session can leave you exhausted even though you never swam at maximum intensity. Research in swimmers shows that session ratings are influenced by swimming volume and repetition length, as well as intensity. Published scale, research on session exertion

Your rating should reflect your own experience, not what your coach expects or what another swimmer reports. Becoming familiar with the descriptions helps make your ratings more consistent. You do not need to attempt a maximal swim to start using the scale.

What is happening inside your body?

Your body produces lactate as it processes carbohydrate for energy. Lactate is also a useful fuel, rather than simply a waste product. Its concentration in the blood reflects the balance between how quickly it enters the blood and how quickly it is taken up and used elsewhere. Measuring that concentration during progressively faster swimming helps describe the physiological demands of different paces. Blood lactate explained

Two markers are commonly used to interpret this response. LT1, the first lactate threshold, marks the initial sustained rise above baseline. LT2, the second lactate threshold, is a higher breakpoint where lactate rises more sharply as exercise intensity increases. These markers help coaches distinguish training intensities, although their exact location depends on the testing method. They are not sudden switches between energy systems. Lactate thresholds explained

What the swimming research suggests

A 2020 study examined six elite Italian open water swimmers completing six progressively faster 500 metre swims in a pool. Researchers measured blood lactate and collected effort ratings after each repetition. Their proposed model placed ratings of 3 or less below LT1, 4 to 6 between the thresholds, and 7 or more above LT2. Read the study

That provides an interesting connection between how swimming feels and a measured physiological response. However, six elite swimmers cannot establish universal targets for everyone, and an effort rating cannot tell you your blood lactate level. My practical takeaway is to use RPE alongside pace and coaching observations, rather than treating the numbers as a precise prescription.

Using effort to judge your progress

When I watch my swimmers, I am interested in whether additional effort is producing useful speed. A swimmer might increase their stroke rate but lose control of their catch, or work noticeably harder for very little improvement in time. Asking how the repetition felt helps us compare what they experienced with what I observed.

One useful sign of progress is swimming faster at a similar perceived effort under comparable conditions. Suppose a familiar marked loop takes 12 minutes at RPE 4. Several weeks later, it takes 11 minutes 40 seconds at the same rating. If that pattern repeats in similar conditions, it suggests their pace at that effort may be improving.

Completing the loop in 11 minutes 15 seconds at RPE 7 tells us something different. The swimmer has gone faster, but they have also worked considerably harder. That can be appropriate for a harder session, but it does not answer the same question about progress at a consistent effort.

I would use an occasional repeatable swim as a check, rather than trying to beat the previous time every session. Agree on a manageable effort with your coach, record the result and compare it with earlier attempts. Holding a familiar pace more comfortably, or maintaining it without such a large rise in effort towards the finish, can also be useful signs to discuss.

Keeping track in open water

Choose a familiar route with a few consistent landmarks where you can briefly check your effort without interrupting navigation. You might remember a rating from early in the swim, another around halfway and one near the finish. Where practical, decide on the rating before looking at your watch so the time does not influence your answer.

Once ashore, record the route, time and checkpoint ratings in a phone note, voice memo or training diary. Add the conditions that mattered, including chop, current, wetsuit use and whether you were drafting. A note such as “RPE 3 early, 4 halfway and 5 coming back into the chop” provides more context than a finishing time alone.

Keep those checkpoint ratings separate from any overall rating for the session. Also remember that a different swimming line, favourable current or drafting opportunity can change your time without indicating a fitness improvement. Look for patterns across comparable swims, rather than drawing conclusions from one particularly quick or difficult day.

If a familiar pace repeatedly feels unusually demanding, I want my swimmers to tell me. We can review their recovery, the conditions and their technique before deciding whether to adjust the training. All of this should fit within normal open water safety arrangements, with others or appropriate support, and without chasing maximal efforts.

Bringing it back to racing

For me, the value of tracking effort is developing a clearer understanding of my swimming. Training gives me opportunities to compare how an effort feels with the pace it produces and how well I can sustain it. Over time, that provides a better basis for making decisions when the circumstances are less predictable.

When the swimmer ahead accelerates, I still have to decide whether to follow. Knowing my own effort will not make that decision for me, but it gives me more to work with than the fear of being left behind.