Why running at a threshold heart rate is beneficial for Ironman run training & factoring in heat

RUNNING AT THRESHOLD HEART RATES - YOUR GUIDE TO IRONMAN MAN RUN IN THE BUILD PHASE

Embarking on the journey of training for an Ironman triathlon is confusing at best with the amount of information available out there. Among the myriad aspects of training, understanding and utilising heart rate zones is crucial for optimising your performance. In this blog, I will delve into the benefits of running at 89% of your threshold heart rate and explore why it's acceptable to allow a slight increase in heart rate during hot and humid weather.

The Significance of Heart Rate Training

Heart rate training is a valuable tool for endurance athletes, providing insights into the intensity of their workouts. Athletes often train within specific heart rate zones to target different physiological adaptations. One such zone is around 89% of your threshold heart rate, which corresponds to a challenging yet sustainable effort. Incorporating this intensity into your running regimen can yield numerous benefits, especially when preparing for the running segment of an Ironman triathlon.

Benefits of Running at 89% of Threshold Heart Rate

  1. Improved Aerobic Capacity: Training at 89% of your threshold heart rate challenges your cardiovascular system, enhancing your body's ability to transport and utilise oxygen. This leads to improved aerobic capacity, crucial for the sustained effort required in the running portion of an Ironman.

  2. Increased Lactate Threshold: Running near your threshold heart rate helps raise your lactate threshold, the point at which lactic acid begins to accumulate in your muscles. By pushing this threshold higher, you can sustain a faster pace for a more extended period before fatigue sets in.

  3. Enhanced Fat Burning: Exercising at this intensity encourages your body to rely more on fat as a fuel source. This is particularly beneficial for Ironman training, where endurance is key, and efficient fat metabolism becomes crucial during the long-distance run.

  4. Specificity for Ironman Running: Training at 89% of your threshold heart rate mimics the demands of Ironman running, helping your body adapt to the specific intensity you'll encounter on race day.

Adapting to Hot and Humid Weather

Training conditions are not always ideal, and weather fluctuations, especially heat and humidity, can impact your heart rate and performance. Here's why it's acceptable to allow a slight increase in heart rate during such conditions:

  1. Increased Cardiovascular Strain: Hot and humid weather can elevate your heart rate as your body works harder to dissipate heat. This increase is a natural response to maintain a safe body temperature, and pushing too hard to stay within a specific heart rate zone may lead to overheating.

  2. Focus on Effort Perception: In extreme weather conditions, it's essential to prioritise your perceived effort over strict adherence to heart rate zones. Listening to your body and adjusting your pace accordingly ensures that you stay safe while still benefiting from the training session.

  3. Adaptation to Environmental Stress: Exposing yourself to variations in weather conditions during training helps your body adapt to the stressors it may encounter on race day. This adaptability is crucial for success in an Ironman event.

Conclusion

Running at 89% of your threshold heart rate is a valuable component of Ironman training, providing specific physiological adaptations that are beneficial for long-distance running. However, it's crucial to recognise that training is a dynamic process, and adapting to environmental factors is equally important. By understanding the interplay between heart rate, effort perception, and external conditions, you can tailor your training to optimise your performance and enhance your chances of success in an Ironman triathlon.