Cycling in the heat

It’s 13:20, and it’s 37 outside and 29 in my (home) office and the sun is just moving around to this side of the house. I think that’s over 2 degrees above the record for Oxford. I skipped my scheduled ride this morning because I woke up super hot, and I have the rest of the week off anyway. It’s hard to get motivated when you are to hot before you even put your bike clothes on, and you know it will be worse by the time you’re done and take them off.
By Thursday it should go back down to a more normal 21 degrees (outside)!

3 Likes

Sounds like a very sensible decision. I got a couple or three of hours of Z2 in first thing this morning, but it’s a fair bit cooler up here in Cumbria, and my house has thick walls. It’s definitely too hot now, though. Work means i’m going to struggle to get more than an hour a day on the bike until next week.

Guys, have you also experienced a reduced performance for a given RPE? It’s been a while that where I live (Mallorca) temperature is around 30 but during last few days it ramped up to 34 with no clouds around and my numbers are 10% lower for the effort

Absolutely.

You’re probably used to drinking lots of water, but also make sure you’re getting enough electrolytes

1 Like

Yes - I went out Saturday, which while nowhere near as hot as today and Monday was still a bit over 30 degrees at some points (open road with no shade gets v hot). That’s much hotter than I am used to riding in given a nice day in the UK is anything 20-25 degrees… It definitely felt harder than it should especially towards the end. Regretted having the extra climbs in there :smiley:

1 Like

It’s been stupid hot in Texas this year, 40C and higher many days and we also have humidity.

Yes, you can acclimate, but it’s kind of like altitude. You can adapt to a point, but (in my experience) you won’t be able to do the same power/duration in 40C heat as you could at a reasonable temperature. While it’s good to get some heat adaptation, the quality of the workout is poor when your power is reduced.

I’ll do my v02max and threshold intervals on a trainer in the AC so I can hit my numbers. 1-2 hour Z2 work is manageable outside, even in the heat of the day (with crazy high heart rate). The hard one is my weekly long ride (6-8 hours with a mix of high endurance, tempo, threshold). I’ve been leaving at 4am and it’s usually really humid at the start, but manageable until 11 or 12 and then power just falls away. I’ve tried all kinds of things to combat this, but I think the body just doesn’t have the cooling capacity once you get past a certain point. I always weigh myself before and after these rides to see how I’m doing on hydration and I can sometimes be pretty close, so it’s not a dehydration issue.

5 Likes

I did Hell of the North in Paris Texas this past weekend with the goal of doing 100 miles. First 3 hours went really good and i was fueling primarily with Skratch Super Fuel and plain water in the bottles for extra hydration. Once the heat really kicked in, all the data points went sideways. Heart rate went up 10-15 BMP, power dropped and probably the worst was gastric emptying stopped. Started feeling bloated and just couldn’t take in the right amount of fluid. Bagged it at mile 62 as it was just a training ride and I didn’t need to dig a hole. 103 degrees F when I loaded the bike.

Plan on doing some walks in the heat post trainer rides this week (acclimation) and have another 5 hour outdoor ride on tap for this sunday. Temps in North Texas will be around 105 F that day as well. Doing what I can to acclimate to the heat but it’s pretty ridiculous out now.

Ron

2 Likes

as many ice socks as possible, and make them HUGE. it makes such a big difference. That said, once it hits 35+, it’s going to be HOT…a great strategy is to reduce hard surges, let people peter out around you; it can become a war of who is last standing versus who has the biggest attacks in the last hour. The heat changes everything.

And don’t believe the Garmin device. True adaptation takes way longer than 2 weeks time; you’ll continue to improve with performance in heat over time.

2 Likes

I did the Gravel Locos 155 mile race in May and similar heat (over 100F by the end). I think it’s an effective race strategy in these conditions to go hard early before the heat and then survive to the finish. No amount of pacing early is going to give you the ability to go hard once it gets really hot, so go hard while you can (within reason) and get as far forward on the course as possible before you have to ease off in the heat. I agree that plain water is the easiest to consume once you’ve been in the heat for a while, but you really need to keep consuming some level of electrolytes and sugar. I’ll typically start a race with skratch that is nearly full strength and then taper to about half strength or less as consumption increases and it gets hotter. Trying to drink full strength sugary hydration when you are drinking 2+ liters an hour is tough and most folks would run into issues.

1 Like

Now 40C at 6:20pm in East of England

2 Likes

Just a tad warm on my commute home. The headwind was not welcome (even more than usual)

I did this race last year. The 100 miles was tough and became dangerous for me. Despite stopping at every water stop and store and carrying two bottles plus a hydration pack I ran out of water at about mile 85. I actually stopped at a house and knocked on the door and a kind lady gave me some cold water. That was the only thing that got me to the finish. I actually finished second in the 100 - I think because most people were smart enough to bail. I saw the route was similar this year and decided to skip it. If I’m riding in 100F weather I find I need to stop more often if only for ice. Hot water doesn’t help much - I need ice to lower body temperature. Instead I mapped a 100 mile ride in the city so I could stop often. Even with that I shortened it to 92 miles as the heat started to get to me midday.
As others have mentioned the body seems to regulate power output as the body temperature rises and my power output really dropped in the last hour even though my legs felt pretty good.

2 Likes

They need to rethink the aid stations as the second 50 only had 1 aid station at mile 85. My awesome wife was running SAG/Support and we had a plan, had I not bailed early, to meet me at mile 75 for water/aid. Even then, I think 75 would have been too far out for myself. The winner of the 100 had a write up on Strava and he mentioned running dangerously low on water while trying to push the finish.

Ron

I did Gravel Locos this year and went through an aid station that ran out of water. And I was mid-pack. I was incredibly thankful I had on a camelback. I would have quit without it.

Same here. Had ice only. And it was so remote the closest water and ice took forever to get out there. I ran out of water with 15 miles to the next aid station. Fortunately I had family waiting at the aid station and they brought me water to get me there. Many were walking by pushing bikes also out of water. I wish we had brought a cooler full to hand out. I was running out again before finding a guy in truck at mile 86 handing out water. I had decided that day not to wear a pack or mount a third bottle cage which was a mistake. It was obviously warmer than expected that day but events in hot weather need aid stations every 20 miles or so and/or route through towns with stores.

1 Like

Yep. I’m not sure I’ll do that one again unless they specifically advertise something like “we will not run out of water”. I’m not sure I’d trust them though after they changed the beginners route the night before and refused to mark the course where it changed. Just not sure it’s worth it to sign up again for an event where the promoter isn’t going out of their way to ensure safety.

Yeah, the course marking thing isn’t great, but I personally never count on course markings. I know of 2 different events in TX where locals (who don’t care for cyclists) changed with course markings to mess up the event. Some gravel promotors don’t even mark the courses, “spirit of gravel” and all that…

Running out of water on a day like that is inexcusable and potentially life threatening. Some people probably quit because of that and some probably pushed on without enough water. When I finished, there was a line of people getting IV’s and 2 ambulances. I don’t know if anyone had serious issues, but things can go sideways in a hurry when you are out in the middle of nowhere.

1 Like

Just in case it wasn’t clear, they changed the course the night before at 7pm and only posted the change on Facebook. They only changed the short course, but these are the people with the least experience. Not much notice and I’m sure lots never heard. It would have been a simple thing to park a truck at the intersection and point people the right way after making a last minute change like that.

Sadly one can not avoid training in the heat where I live.
You pass 0900 and you’re cooked.
Evenings get below 30° now only after 2100.
The fact that it’s also very humid just makes it even worse.

So…what are my insights:

  1. Heat acclimation - let the body get used to perform in hotter temperatures, as the summer starts.
  2. Either train very early or very late.
    Training when it’s too hot is not productive when it’s done as a regular workout on a regular basis.
  3. Follow the certain data/ metrics during the session to check for your heat stress:
    a. Heart rate - is your pulse higher at the same effort and going up.
    Best indicator and even better than RPE.
    b. RPE - does it feel too hot.
    Very subjective and inaccurate but can be indicative.
    Support it with heart rate data.
    c. Sweat - do you sweat significantly more?
    If your body is too hot consider either changing the workout or cutting it short.
    If you start getting the chills…dump water over your head and rest.
    You over done it.
  4. Two cool bottles - one to drink from and one to pour water on yourself, on a regular basis.
  5. Hydration - liquids before, during and after.
  6. Osmolarity - electrolytes, try before.
    During the session can have too many undesirable outcomes (when it comes to an hour long session).
  7. Cool yourself after.
    Nothing like draining a cool bottle of water and a chilled shower after.

The good news…waiting for mid September for things to become normal.
Sadly it is what it is.

2 Likes

Sounds like you live where I live. Oddly, I NEVER take cold showers. I spend 30 minutes cooling down after the workout, only to jump in a steaming hot shower and then start sweating as soon as I step out. Not smart, I know.