To thrive (or just survive) in swimrun you need a range of skills from being able to navigate tricky running trails to coping with challenging open water conditions. Importantly, however, you need to build these skills on top of a strong aerobic base. Most swimrun events take at least a couple of hours to complete; some take many more.
To improve your swimrun aerobic capacity, you need to run and swim a lot. Developing a consistent swimming and running habit and sticking with it will give you a great base to build on. For top-level performance, you will obviously need to do more, but don’t underestimate how far a solid training base will take you.
One way to help motivate yourself to swim and run consistently is to set annual distance targets for both activities. Then, work out what you need to cover each month, week and training session to get there. Remember to build in some slack to allow for holidays and sessions missed for illness or emergencies. For example, say you set yourself targets to swim 500km and run 1,500km in the year and assume you do three sessions of each activity each week. You would need to average 3,200m of swimming per session and 9.6km of running. Build in some headroom and make that 3,500m of swimming and 10km of running. You can split this up however you like: maybe do a long run of 16km at the weekend and two shorter ones of 7km each mid-week. This would work well if you wanted to include a tempo run or speed intervals in your training. You may also want to make monthly adjustments if you want to increase distances as the year progresses, and cut back in the lead-up to races.
Next, create a means to track your swims and runs. I like to use a spreadsheet that I’ve set up to show me how I’m doing against targets. This one from Outdoor Swimmer is set up for their Million Metre Challenge (swim 1,000,000m in a year) but can easily be adapted for running and different total distances.
Hopefully, you love swimming and running so much that you don’t need additional motivation to do them. However, if you are anything like me, you may sometimes need a push to get yourself out of bed for an early morning run or to unpeel yourself from the sofa for a late evening swim, especially in the depths of winter. The thought of having to log a zero on my spreadsheet, and having to make up the distance another time, is usually enough to get me moving. I also find I’m less likely to cut my runs short if I have an annual target. Keeping on track and seeing the distances mount up is surprisingly satisfying.
Another underappreciated benefit is the confidence boost you get from seeing the accumulated distance you’ve swum and run. The numbers and charts in the spreadsheet are a lovely visual reminder of what you’ve achieved. If you’ve got an event coming up, it’s worth looking back at what you’ve done. It sounds trivial, but it works. I even think about the training I’ve done if I hit a low point during a race and turn it into a mantra. Something like: “You’ve got this. You’ve done the distance. You’ve got the proof.”
Just one word of caution: mindlessly logging miles is not the optimum way to improve at swimrun. You should also think about (among other things) technique in swimming, vary your running speed, practice hills and get comfortable using your kit. The annual distance challenge is just another tool in your box, and not the total solution to becoming a better swimrunner.