Real-World Heat Training: Coach Tim Crowley

Many coaches of amateur athletes have discovered the benefits of CORE, and we’re spotlighting how some of them use the device with themselves and their athletes. We recently spoke with Tim Crowley of TC2 Coaching.

How long have you been using a CORE sensor?

I have been using the CORE sensor for 8 months. Since I live in central Florida where it is hot and humid 8 months of the year, the sensor has been invaluable for heat acclimating, training, and racing. CORE also allows me to train and race safer. After several medical tent visits after races (one that almost killed me included 11 liters of IV), I take heat training seriously.

This past summer has been the most enjoyable in the 11 years I have lived in Florida, due to using the CORE sensor, even though it's been the hottest summer on record. I am able to train better and recover daily.

As a coach and triathlete for more than 35 years, I have found monitoring core body temperature to be one of the biggest breakthroughs in training science. As I get older, I need to learn how to train and race smarter if I want to stay competitive.

Are heat sessions done as part of a bike or run workout? Or both?

Both cycling and running workouts are used for heat training. During the summer months, long interval sessions on the bike always put me into the heat zone. While pretty much any run over 30 minutes will get me in the zone as well. During the warm months, I may use indoor sessions to keep temps lower for higher quality sessions.

Can you give details on some of the workouts that include heat sessions?

  1. Run/bike. During a 40–60 minute run speed workout, I will generally get into the heat zone after about 30 minutes. After the run, I'll take a 30-minute break to refuel and change clothes, but my core temperature will stay in my zone. I'll then do a 60 to 90-minute easy-to-moderate ride that will keep my core temperature in my training zone the entire time giving me close to 2 hours in my heat training zone.
  2. Indoor bike workouts. I will overdress and not use a fan, and I will take about 25 to 30 minutes to enter my heat training zone. At that point I will take off the extra clothing and turn on a fan. This will allow me to stay in my zone for the remainder of the workout. Riding inside allows me to control my body temperature a lot easier.
  3. Treadmill sessions. Similar to the bike workouts, I will do a 20-minute warm-up outside which will bring me into my heat training zone for running. Then I will do an interval session on the treadmill and control the temperature with the use of a fan, long-sleeved jerseys and winter hats.

What is your Heat Strain Index during these workouts?

The Heat Strain Index on typical summer runs is 3–4, and 2–3 on the bike. During very hot and humid weather I’ve had a run that went to 6.7 (that was tough) and 2-hour bike intervals session that was at 5.15.

How is core temp increased?

During the summer months in Florida, it is not difficult to raise core temperature. It is often difficult to keep it from rising outside the heat zone. Having spent most of my life in a colder climate before moving to Florida, I have now found a good use for all of my winter gear as I can use this to overdress on cooler days and for indoor sessions to raise body temperature.

I also use my garage/training center which is insulated to keep it around 72 to 78° year-round. This makes it easy to raise body temperature by adding a little bit of extra clothing.

Is a sauna/hot bath used to extend the heat session?

I have a hot tub and have found it to be one of the most valuable pieces of training equipment that I own. I use it every evening as part of recovery and to allow for quality sleep. I also use it 2 to 3 times per week after hard or long run sessions where my core temperature is at the high end of the training zone or slightly above. 10 – 15 minutes in a 105° F (40.5° C) water boosts my core temperature a little higher. I do not wear the sensor in the hot tab but put it on immediately after getting out to monitor my temperature. I can stay in the heat training zone for an additional 30 to 50 minutes after the hot tub session, giving me about 90 minutes total.

Anything else you want to add?

I have found heat training to also help with swimming in a warm pool or open water. I find I do not overheat during long or hard swims. Also,drinking 30 oz electrolyte drink before hot runs and 20oz of slushy drink in am insulted bottle during runs helps keep the core temp from rising too fast.