How to keep fitness levels up
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How can I keep my fitness levels in open water?

Swimming coach Cassie Patten shares her advice for how to maintain fitness levels in open water.

You ask, we answer! This month Outdoor Swimmer reader Jenny Morre asks swimming coach Cassie Patten about how she can maintain her fitness levels in open water

“I am 40 this year and I was a competitive swimmer in my youth. I have always swam training sessions in the pool until earlier this year when I gave open water a go and loved it. The issue I am having is I feel like I have lost speed and general fitness. I just go to the lake and swim 2km at the same pace as I have no session to follow. How can I swim in open water and keep my fitness up?” Jenny Morre, Swindon

Swimming coach Cassie Patten answers:

I recommend you look at your lake swims as training sessions, as you would do if you were swimming in a pool.


Before you get in, set yourself a session. If you find it difficult to remember a whole session, write it on laminated paper and secure it to your tow float. This can be rubbed out and reused for your next swim.

An example session could include the following:

Warm up. It might be that you swim continuously for five minutes or you swim 400m at 50-60% of your max effort.

Pulse raiser. Aim to raise your heart rate to about 70% of your maximum heart rate, or so you are quite out of breath. I usually do 8 x 50m, building to 1-4 x 50m at 50-60% effort then hit the last 4 at 70%. For rest I would take 20 seconds rest or enough so I can swim again at the same intensity.

Main set. This is completely dependent on what the focus the session is on. It could be a heart rate set where you swim 10 x 100 as fast as you can, with 45 seconds rest. Or a longer distance technique set where you swim 500m with 40 seconds rest, 400m with 30 seconds rest, 300m with 20 seconds rest, 200m with 10 seconds rest and finish with 100m.

Swim down. A steady section at the end to allow your body to relax and your muscles to stretch out.

Measuring speed and distance

I know what you are thinking: ‘How do I know how far and how fast I swam?’ If your lake has different courses of set distances, you will easily know how far you are swimming.

If where you swim is just one continuous loop or you are swimming in the sea, try using a GPS watch.

Finally, count how many strokes it takes to swim 100m. This way, even when you do not have your watch you still have a rough guide of distance.

It is slightly more difficult to complete a training session in open water, but using my top tips you should feel more confident in replicating pool sessions at your local lake.

Our expert Cassie Patten won bronze in the first ever Olympic 10km marathon swim at the Beijing 2008 Olympics. She is head coach at WaveCrest swimming. To submit your swimming query to Cassie, email editor@outdoorswimmer.com. Read more about training and technique for open water swimming.