Heart rate variability (HRV) has been hyped.

Maybe due to Whoop or the influx of dedicated podcasts now talking about the subject.

But what is HRV and why does it matter?

If you’re like me you know its’s a signal of your health.

But is that it?

The Main Feature

Leg one: What is HRV?

Heart rate variability (HRV) refers to the variations in time between successive heartbeats. HRV has been studied for several decades, and the relationship between HRV and health has been well established. HRV is an important biomarker that can provide valuable insights into an individual's health and fitness status.

Heart rate variability is the measurement of the variation in time between successive heartbeats. It is an accurate indicator of the balance between the sympathetic and parasympathetic branches of the autonomic nervous system (ANS). The sympathetic branch of the ANS is responsible for the "fight or flight" response, while the parasympathetic branch of the ANS is responsible for the "rest and digest" response. HRV reflects the interplay between these two branches of the ANS and provides valuable insights into an individual's physiological state.

Why is it a key data point in understanding our health?

HRV has been extensively studied in the context of various health conditions, including cardiovascular disease, diabetes, and depression. In general, a high HRV score is associated with better health outcomes, while a low HRV score is associated with increased morbidity and mortality. The primary reason HRV is a key data point in understanding our health is that it provides a non-invasive way to assess the function of the ANS, which plays a critical role in maintaining homeostasis in the body. HRV can provide valuable information on an individual's cardiovascular health, stress levels, and overall well-being.

T-1: Mental Preparation

Leg 2: Relevancy

HRV has become increasingly relevant in the field of sports science, particularly in the context of endurance sports such as Ironman, triathlon, and marathons. These sports place a significant physiological demand on the body, and monitoring HRV can provide valuable insights into an athlete's readiness to train and compete. HRV can also help identify signs of overtraining and prevent injury.

Endurance athletes have been shown to have higher HRV scores than sedentary individuals. This is likely due to the increased demand on the cardiovascular system during endurance training, which leads to adaptations that improve cardiovascular function. Monitoring HRV can help endurance athletes optimize their training by identifying periods of high and low readiness to train. This can help prevent overtraining and optimize training load to achieve peak performance.

For my experience, over time you can start to feel when your HRV is on the way down, hinting to you to take a few recovery days.

T-2: Gear to change into

• Whoop 4.0 health tracker. Shop here.

• Oura Ring health tracker. Shop here.

• Garmin MARQ Athlete Gen 2 watch. Shop here.

• Fitbit Sense 2. Shop here.

Shop natural supplements formulated to enhance performance: 

🌱💊 542 Performance Nutrition Daily Green’s ultimate super greens capsules are a perfect blend of superfoods, vitamins, minerals and wholefood-sourced ingredients enhancing your immune system to help you perform in training.

🍄 542 Performance Nutrition Mushroom+ capsules are single-ingredient, high-strength mushroom supplements, helping you deliver energy to your body for training.

💪 542 Performance Nutrition Marine Collagen is the highest quality, and most bioavailable source of collagen available, helping to provide structural integrity to joints and bones.

💤 542 Performance Nutrition Ashwagandha+ (KSM66) is formulated with Cordyceps & Ginseng to help combat stress and adrenal fatigue, while also supporting the immune system, energy levels & mental performance. 

🏋️‍♂️ 542 Performance Nutrition Plant Protein delivers 17g of premium vegan protein per serving with just 1.5g of carbs, 88 calories & no artificial sweeteners.

🏋️‍♂️ 542 Performance Nutrition Whey Protein delivers 22g of premium whey protein per serving with just 1.2g of carbs, 108 calories & no artificial sweeteners.

Leg 3: Application to endurance sports

One way HRV can be used in endurance sports is through daily monitoring. Athletes can measure their HRV each morning using a heart rate monitor and a smartphone app. This can provide an objective measure of an athlete's physiological state and readiness to train. Athletes can use this information to adjust their training load and avoid overtraining.

HRV-guided training involves adjusting training load based on an athlete's HRV score. For example, if an athlete has a low HRV score, they may reduce their training load for that day or focus on recovery activities. Conversely, if an athlete has a high HRV score, they may increase their training load or focus on high-intensity training.

Research has shown that HRV-guided training can improve performance in endurance sports. In a study published in the Journal of Strength and Conditioning Research, researchers found that HRV-guided training improved running performance and reduced injuries in a group of collegiate cross-country runners. In another study published in the International Journal of Sports Physiology and Performance, researchers found that HRV-guided training improved performance in a group of elite triathletes.

HRV is a powerful tool that provides valuable insights into an individual's health and fitness status. It reflects the interplay between the sympathetic and parasympathetic branches of the ANS and provides information on an individual's cardiovascular health, stress levels, and overall well-being. HRV is particularly relevant in the field of sports science, especially in the context of endurance sports such as Ironman, triathlon, and marathons. Monitoring HRV can help athletes optimize their training and prevent injury by identifying periods of high and low readiness to train. HRV-guided training has been shown to improve performance in endurance sports and reduce the risk of injury.

Adding HRV to the data you analyse can help you navigate training & maximise your performance.

So wear that Whoop, invest in your tracking & elevate your understanding of how your body is feeling.

Aid station: Listen as you recover

• Whoop Podcast: World-renowned HRV researcher Daniel Plews discusses everything you need to know about performance and training. Listen here.

• Modern Wisdom: #264 - Joel Jamieson - An expert guide to HRV & how to improve it. Listen here.

• Huberman Lab: Fitness Toolkit: Protocol & tools to optimise physical health. Listen here.

• Rich Roll: Coach of the Norwegian train - Olav Aleksander Bu on the science of elite performance. Listen here.

Coaches Corner

WOTW: Workout of the week

This cycling workout is designed to improve your endurance and build your cardiovascular fitness. The workout consists of a warm-up, main set, and cool-down. You will need a stationary bike or an outdoor bike with a power meter and heart rate monitor to complete this workout.

Warm-up:

• Start with a five-minute easy spin at a low intensity with a cadence of 80-90 rpm and a power output of 50-70% of your functional threshold power (FTP) to warm up your muscles.

• After five minutes, increase your cadence to 90-100 rpm and maintain the same power output for two minutes to raise your heart rate.

Main set:

• Interval 1: Start with a 10-minute effort at a power output of 75-85% of your FTP, maintaining a steady cadence of 85-95 rpm. After 10 minutes, increase the power output to 90-100% of your FTP and hold this power output for two minutes, cycling at a high intensity. Recover for two minutes at a power output of 50-60% of your FTP with a cadence of 80-90 rpm, then repeat this interval four more times.

• Recovery: After completing the first interval, cycle at an easy pace for five minutes at a power output of 50-60% of your FTP with a cadence of 80-90 rpm to allow your heart rate to recover.

• Interval 2: Start with a five-minute effort at a power output of 75-85% of your FTP, maintaining a steady cadence of 85-95 rpm. After five minutes, increase the power output to 95-105% of your FTP and hold this power output for four minutes, cycling at a high intensity. Recover for two minutes at a power output of 50-60% of your FTP with a cadence of 80-90 rpm, then repeat this interval two more times.

• Recovery: After completing the second interval, cycle at an easy pace for five minutes at a power output of 50-60% of your FTP with a cadence of 80-90 rpm to allow your heart rate to recover.

Cool down:

• Finish with a five-minute easy spin at a low intensity with a cadence of 80-90 rpm and a power output of 50-60% of your FTP to cool down your muscles and bring your heart rate back to normal.

• After five minutes, stretch your quads, hamstrings, calves, and back to prevent soreness and improve flexibility.

This workout will challenge your cardiovascular system and help you build endurance for cycling. It is important to stay hydrated, listen to your body, and adjust the resistance, cadence, and power output to suit your fitness level and training goals.

Finishing line: Races next week

• Oldbury White Horse Sprint Triathlon. Explore here.

• The Canyons Endurance Runs by UTMB - 100k, Auburn, United States. Explore here.

• Greensand Way Ultra Marathon, Guildford, United Kingdom. Explore here.

• Run Through Gateshead Half Marathon. Explore here.

Tweet-athlon

MemeOTW

Thank you for reading this weeks newsletter.

You can keep up with us daily on Instagram here and follow my (Robert, triathlete - Ironman 70.3 athlete) Strava here.

Currently training for Ironman Staffordshire in June.

DM me on Instagram personally if you're London based - we're always out for group runners & rides. Connect here.

Have a great week.

Robert