Heat Acclimation

It’s no secret that Ironman Louisville is one of the toughest races on the planet. I went into some details as to why on this previous post. The weather plays a large factor in the difficulty of completing the race. Here’s what the weather has been like for the first four years of IMLOU:

2007 – 92° F and high humidity
2008 – 93° F and high humidity
2009 – 75° F and moderate humidity
2010 – 94° F and high humidity

So as you can see, with the exception of 2009, it’s been down-right nasty. What will it be like this year? The extended forecast (still 10 days out) is calling for “extreme heat” with a temp in the high 90’s!
I think everyone understands why this heat poses problems for endurance athletes. Studies have shown that heat in the 90’s can lower the body’s ability to perform by 7-10%. The average finish times for IMLOU in 2010 (94° F) and were over 45 minutes longer than in 2009 (75° F).
Exercising in heat also makes your heart rate higher than normal, increases your core temperature to dangerous levels, causes lactic acid to build more quickly (causing muscles to shut down), and can ultimately lead to heatstroke.
I’ve witnessed first-hand my wife carry and give birth to both of our children. I know that the human body is incredible! Believe it or not, your body can adapt for any condition, including extreme heat. Exposure to warmer conditions causes the body to become more efficient in keeping core body temperature low. Here’s how your body adapts:
  • Sweating will start at a lower body temp (cooling starts earlier)
  • Sweat rate increases to help keep the core cool
  • Blood plasma levels increase, allowing the heart to beat slower and the body to sweat more before performance decreases.
  • Your thirst mechanism improves, causing you to drink more
  • Salt loss through sweat decreases
There are several methods out there to acclimate your body to heat. Most methods claim that it takes about two weeks for the body to achieve the items listed above. The method that I had planned on using required 90 minutes of exercise outside in the afternoon heat 3-4 times a week for the two weeks leading up to the race. I had planned on doing all of my runs in the afternoon and even a few bike sessions. However, due to my IT Band issues, there’s no way that I’m going to run 90 minutes this week or next.
So the other option that I found involved something a lot more mind-numbing…sitting in a steam room. With the recent break in the temperatures here in Louisville, it’s only been in the low to mid 80’s in the heat of the day, so I’m not sure running outside would have done the job anyway.
The gym that I go to has both a dry sauna and a steam room. While the dry sauna actually get’s hotter, there’s no humidity involved. So I’ve opted for the steam room, which is plenty hot enough. Although I’m not exactly sure what the conditons are in the steam room, a little research online shows that they are typically around 110° -115° F with a humidity close to 100%.
So starting this week, I’ve been sitting in the steam room for 30 minutes at a time. If I’m the only one in there, I’ll do my hip strengthening exercises and some stretches for the first few minutes. For the remainder of the time, or if it’s crowded, I’ll just sit there…and suffer. I’m not going to lie – it sucks. I sweat more than I thought possible. I wear my clothes (unlike most people in there), and they are completely drenched within the first few minutes. I continually sip on my water bottle and watch the time move very slowly. By the time I get to the last 5 minutes or so, every minute seems like ten. I’ll try to get in 3-4 more steam-room sessions in the next 7 days. It’s brutal…but hopefully it will help me come race day.
Despite the fact that I live in the same city as the race will be held, I don’t feel like my training has prepared me for extreme conditions. I do just about all of my training in the morning, so with the exception of a few long rides, I haven’t spent much time at all training in the heat of the day. The heat acclimation that I’m doing wouldn’t be necessary for someone that lives in this area and has been training in the afternoon all summer.
Side note: I’ve seen some interesting things in the steam room. I just don’t understand why a guy thinks it’s ok to be in there totally nude with other men around….or put on lotion…or sit spread-eagle on the bench. It’s not cool, stop doing this stuff. Keep a towel on and just sit there and sweat! There’s also a guy that feels it necessary to cover up the humidity sensor and cause more steam to spray in the room every few minutes, making it hard to even breathe. You are not smarter than the guy that designed the room dude, just leave it alone!
Side note 2: If you are one of those guys in the club that sweats all the way through his “club shirt”, you might look into some heat acclimation. You aren’t going to pick up any chicks covered in sweat.


8/5/11 Aqua Jog – (7.0 miles in 1:00:00) 
8/5/11: Weights – Round and Round – 4 sets   
8/6/11: Bike – Endurance Ride (67.54 miles in 3:24:36) 
8/8/11: Bike – Power Ride (14.00 miles in 45:00) 
8/8/11 Aqua Jog – Intervals (7.0 miles in 1:00:00) 
8/9/11: Run – Easy Run (2.06 miles in 16:59)
8/9/11: Swim – Open Water Swim – Ohio River (1936yd in 36:01) 
8/10/11: Weights – Body Blaster – 4 sets 
8/10/11: Swim – Train Smart Group Swim (3200m in 1:14:19)
8/11/11: Run – Easy Run (4.22 miles in 34:24)
8/12/11: Bike – Power Ride (14.00 miles in 45:00) 
8/12/11: Weights – Round and Round – 4 sets   
8/13/11: Swim – Open Water Swim Race- Ohio River (2.4 miles in 1:25:16) 
8/13/11: Bike – Brick ride after swim (31.23 miles in 1:30:59)
8/15/11: Bike – Recovery Spin (19.00 miles in 1:00:00)
8/15/11: Weights – Body Weight Only I – 4 sets   
8/16/11: Run – Easy Run (1.12 miles in 10:03)
8/16/11: Swim – Open Water Swim – Ohio River (1936yd in 35:03) 
8/17/11: Swim – Train Smart Group Swim (2800m in 1:02:30)
8/18/11: Double Brick – Bike (5.5 miles in 18:00), Run (1.34 miles in 10:00), Bike (6.0 miles in 18:00), Run (1.12 miles in 10:00)

One Response to “Heat Acclimation”

  1. Matthew Smith August 18, 2011 at 7:08 PM #

    That heat looks intense! I hope for your sake that it’s raining! Your training looks awesome, and I know you’re going to do so well on this IM. Good call on the steam room to get used to the temps and humidity.

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