Introduction
Running in the heat is one of the more demanding things you can ask of your body. It affects your pace, your effort and your recovery - and ignoring it is one of the fastest ways to derail a training block. REN is built to help you work with the heat, not against it, so you can keep making progress without putting yourself at risk.
Why Heat Affects Your Running
When temperatures rise, your body works harder to cool itself down - which means more strain at the same pace, a higher heart rate, and faster fatigue. What feels like an easy run in cool conditions can tip into something much more demanding on a hot day. That's not weakness, that's just physiology.
Top Tips For Running In The Heat
Run early or late
This is the simplest fix! Early morning or evening running avoids peak heat and UV - most runners find mornings better since the ground and air haven't had all day to build up heat. This may mean an earlier alarm to fuel up before you head out, but the training experience may be better as a result. Just be sure you're getting to bed early enough the night before to maximise on sleep hours - another important factor for preparation and recovery!
Slow down
Heat adds effort even when your pace stays the same. Run by feel or heart rate rather than chasing a number - your easy runs should still feel easy. If you need to adjust your paces a little this week to adapt to the heat, that's fine.
Shorten the session if needed
A 40-minute run in 30-degree heat can be more taxing than an hour in mild conditions. A shorter, smarter session beats a full one that leaves you wrecked for days. Feel free to swap out that intense interval session opting for an easy run instead.
Hydrate before you go
Don't wait until you're thirsty. Start well hydrated and carry water or plan a route that includes a possible water stop for anything over 45 minutes. Electrolytes in your water also go a long way!
Wear the right kit
Light colours, moisture-wicking fabrics, and a cap or visor make a real difference. Avoid anything that traps heat.
Watch for warning signs
Dizziness, nausea, and stopping sweating are red flags. If something feels off, stop - no session is worth a heat-related incident.
How REN Helps
You can log how the heat affected a session by tracking the RPE (Rate of Perceived Exertion) of your workout in the app once completed, helping REN to tailor future sessions accordingly.
REN's scheduling feature also lets you set your availability (Settings Availability) around the week's weather forecast - planning ahead on a Sunday is a great habit to build towards. And if a workout day arrives and you're just not feeling it, you can move any session up to two days forward via the Training Calendar.
Connected with Apple Watch or Garmin, REN reads your heart rate data during workouts - so if your average HR is running significantly higher than usual, your plan adjusts accordingly for the days ahead.
Heat is a variable, not a barrier. So, with the right adjustments - timing, pace, hydration, kit - you can train consistently through summer without compromising your health or your progress. REN is there to help to adapt your plan around your life.
For more tips or support, feel free to reach out to the team!