We’ve been having some heat up here in the corner of the States (Maine). While I KNOW exactly what I am supposed to do to combat bonking….sometimes I fall short.
Let’s talk about what happens to our bodies when we ride during high heat and humidity.
Our bodies are made up of about 60% water. If we dip below even just 1-1.5% of that during physical activity, breakdown starts to occur. High heat and humidity increases the core temperature which in turn quickens the rate of dehydration. When this happens on a hot humid day you will experience any one or more of the following.
- Decreased muscle endurance (“why is this low grade climb so harrrrrrd!?”)
- Aerobic power worsens leading to loss of VO2 MAX to where you can’t utilize O2 properly and find yourself breathing harder than usual (“I can’t catch my breath!”)
- Energy stores are broken down quicker leading to lack of strength (“my legs are so tired!”)
- Decreased blood flow to the heart (“my heart feels like it’s pumping out of my chest!”)
- Lack of focus leading to poor performance (“I never miss this drop!”)
Yesterday after work I jetted over to a trail where I wanted to get some hill work in and finish with a sweet downhill flow. It was hot and humid and I had been drinking (what I thought) was enough water at work. CLEARLY not. I pushed hard, real hard on the climbs. All in all I was riding surprisingly well! Right about at the 50 minute mark it set in….I had to talk myself out of seriously vomiting. I gathered myself as best I could, decided to cut the ride short and hit a small climb to the flow trail. As I started the normally easy-ish climb, I was done….officially bonked and had to bail. So disappointed that I was going to miss out on that sweet flow back down but I knew I had to call it for safety reasons. I was riding alone and didn’t need another crash like the one above.
So let’s talk about what to do in order to mitigate dehydration during high heat and humidity. It’s not just about drinking some water….
Be diligent about hydrating constantly. The Institute of Medicine recommends a baseline of 91 oz of water for women and 125 oz for men. YET, during activity this needs to be adjusted. Think before, during, and after. American College of Medicine recommends 17 oz two hours before and 7-10 oz every 20-30 minutes during high activity. EVEN YET, aim higher during high heat and humidity. Then, at about the 50-60 minute mark (if you are riding on) it’s time to add quick digesting carbs, 15-30 grams (up to 30 grams/hr if you have a long ride lasting 2+ hours). Gels or gummies are my go to. After your ride, continue to hydrate aiming to keep urine clear right up until bedtime. First thing upon waking the next day chug 8 oz of water before breakfast or coffee. And lastly, train in the heat and humidity. Workout, do box jumps, KB swings, squats jumps and climb intervals all within reason. This will help you acclimate to longer bouts of heat and humidity.
So to recap.
1- Think before, during and after (up until bedtime).
2- Add more fluids during high heat and humidity days.
3- Acclimate at the trail head by doing a warm up before the ride.
4- Dynamic training outside for added acclimation.
5- Don’t forget the carbs and proper nutrition during rides lasting 2+ hours..
Alright! I’m always here for you if you have any questions on strength, conditioning, recovery, nutrition and more to enhance your MTB lifestyle.
Ride stronger, longer, and happier.
Your coach, Tennyson.