Demystifying Heart Rate Training: The S3 Multisport Approach

Heart Rate training is one of the most studied and misinterpreted performance metrics that we have at our disposal as endurance athletes. The area of misinterpretation is largely seen when athletes and coaches base the HR zones on max heart rate. This is especially true when using the formula of 220 minus Age = max heart rate. The foundation of the S3 Multisport training philosophy is to ascertain an individual’s Lactate Threshold Heart Rate (LTHR) and this max HR formula’s charts/algorithms are simply not accurate. At S3 Multisport, for cyclists and triathletes, we have chosen to use a “bike field test” to determine cycling LTHR and extrapolate your run LTHR as a baseline. For runners, the best data is obtained from an open road race or a “5k run test” to obtain starting data. Further data points from training, racing and additional field tests will refine your LTHR and/or provide more confidence that they are accurate.

Let’s delve into a brief explanation of lactate, lactate threshold and lactate threshold heart rate. For the purpose of our discussion, lactic acid and lactate will be used interchangeably although they are chemically different. Lactic acid is by product of muscular fuel usage (respiration) and anaerobic (without oxygen) metabolism. The accumulation of lactate in the bloodstream is a performance limiter in endurance athletes. The key here is “accumulation” and so as we train, our bodies become more efficient at clearing lactate from the bloodstream. The point in which we are producing the same amount of lactate as we are clearing is called our “lactate threshold”. Therefore, the corresponding heart rate at that threshold would be our “lactate threshold heart rate”. In all transparency, the only definitive way to determine a true, extremely accurate LTHR would be to put each person on a bike trainer and/or treadmill and take numerous blood samples over the course of a long, progressive workout. And some people do that! However, there are some scientifically validated algorithms using field tests that approximate a person’s LTHR with good confidence. We decided to use these algorithms in place of the “pin cushion method”. You’re welcome.

We decided to use heart rate training as our main training metrics for several reasons. Heart rate during exercise is more than an “interesting data point” when used as part of a comprehensive training program. Heart rate is a physiological metric that, while not perfect, is the most available and obtainable information of the non-invasive values.

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Here is a list of what heart rate training provides as information:

• During exercise:

  • How hard your body is working during any given pace/power effort

    • ↑ HR with higher the effort

  • Hydration or dehydration level

    • ↑ HR with less optimal hydration

  • Impact of heat stress

    • ↑ HR with heat stress and cardiac drift

  • Recovery from previous training sessions

    • ↑ HR when not fully recovered

  • Non-training stress level

    • ↑ HR with life stress due to hormonal (cortisol, etc.) imbalances

• During rest:

  • Recovery status

    • ↑ resting HR when rest/recovery is suffering

  • Overreaching or overtraining syndrome

    • ↑ resting HR when rest/recovery is suffering for longer periods

  • Sleep efficiency

    • ↑ resting HR when sleep is deficient

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As swimmers, cyclists and runners we have been conditioned that to perform for longer periods or faster, we must train at efforts above what we are planning on racing for the majority of our sessions. This is partially true, but there is much more to the story. Additionally, many theories and plans exist for the “time-crunched athlete” or the “if you cannot train long, train harder”. Again, a partial truth in our opinion. Something that we want to make clear about S3Multisport philosophies and methodologies, we believe there are no shortcuts to optimal, long-term performance gains and health. The longevity and performance gains come from consistency and training that mitigates risk of injury and burnout. Look at it this way, 100% of the athletes that do not start a race, do not finish that race!

Our viewpoint can be simply stated as you will spend the majority (70-80%) of your multisport training periodization at our Endurance sector, or S1, to develop that system as the foundation of each discipline. During the base phase, you will spend close to all your training in S1. Throughout the build and race prep phase, S1 is still the bulk of the training stress for all 3 disciplines. As the build volume increases, the percentage of S1 decreases slightly and is replaced with S2 (Tempo) and S3 (Threshold) time. The proper development of this low intensity, aerobic system is the building block of multisport periodization and decreases the risk of injury by preparing the muscles, ligaments, tendons, and joints for the rigors of the phases to come. Additionally, S1 is where cellular and mitochondrial adaptations of the body’s energy systems are further developed. We will spend many hours a week in this sector, and you will become faster and mitigate risk of injury as you progress through the S1 training.

This S1 sector, during the first 2-4 weeks, may seem like a crawl. Most athletes just ignore staying in the sector and blow right through it because it feels too slow. In all honesty, that is the point, to slow down. The endurance sector takes time to develop as it literally changing you at the cellular level. The process of mitochondrial respiration (the powerhouse of the cell) is beyond the scope of this document, but it is the building block of endurance and aerobic respiration. We are aiming to maximize our body’s ability to efficiently utilize this energy system for long periods of time. We can concurrently develop both the aerobic and anaerobic processes, but it all starts and ends at the cellular level adaptations.

As we learn more about how your specific adaptations are progressing and correlating, we will start to add more intensity and speed sessions. Again, the foundation is laid, and the body is ready to both perform and absorb the training stress at these increased levels. Furthermore, we will also prescribe sessions with specific pace and or power goals (depending on your technology) to not only have you hit objective performance/speed metrics but also to gain additional insight into what you can expect to execute on race day.

The key here to be patient and understand there is a definite method to our madness…or slowness at S1 paces and speed . Do your best to keep your heart rate in S1 (& S2) when prescribed. Over time, you will get faster and more fit spending most of your time in the S1 sector and will reap the benefits of decreasing risk of injury, heat stress and burnout. We promise!

Let us know if you have questions and happy training!