Going Easy to Go Hard.

Over the years there has been a lot of controversy in endurance sports and athletics about training methodologies in regards to intensity. There is High-Volume Training (HVT) also know as Long Steady Distance (LSD), Low Intensity Steady Training (LIST), Threshold-training (THR), High Intensity Interval Training (HIIT), Polarized Training (POL) and other concepts. I mention LIST separate from LSD because LIST is actually done at a "moderate" intensity for up to an hour.

What has emerged from meta-data studies and science is that many elite endurance athletes spend 80% of their time at "low intensity" and 20% of their time at a mix of "moderate" and "high" intensity or Polarized Training. Many of these studies show that the shift to a more polarized approach in training intensities really began to happen in the 1980s when heart rate monitors became more commonplace. From the 1970s to 1990s there has been significant performance gains across endurance sports thanks to these advances in training intensity management. The concept of this 80%/20% guidance or go easy to go hard has lead to numerous coaches pushing the concept such as Matt Fitzgerald's book 80/20 Running, but not delivering the guidance to help athletes define "low."

The key here is that many of these studies took the training logs of olympic and world class athletes. Athletes that are fast and efficient enough that their “easy” heart rate intensity still allows a wide variety in training variables. This changed with a study in 2014 that looked at national level athletes and put them through one of four training protocols: HVT, THR, HIIT, and POL. This was one of the first studies to use athletes closer to your common age-groupers (these athletes were still high caliber with an average VO2Max of 62+) and to put them through a training methodology vs a post-mortem on their training logs. The study used forty-eight runners, cyclists, triathletes, and cross-country skiers and randomly assigned them to one of the four groups for a 9-week training cycle. Through physiological testing they showed that the Polarized Training group far exceeded the others in performance gains with the HVT group having little to no gains in performance. Unlike elites studies show that age group athletes primarily train at moderate intensity with little polarity to their efforts. This leaves the average athlete in a "moderate rut" resulting in missed opportunities.

If age groupers are to ditch the "moderate intensity rut" the key is to find what "low" and "high" truly are. Sports scientists determine the “low,” “moderate,” and “high” zones through lactate or ventilatory equivalents both of which require lab testing. The points used in many of their studies are the ventilatory equivalents for O2 and CO2 or VT1 and VT2 which correlate to about an average blood lactate value of less than 2 mmol·L−1 (LT1) for the “low” to “moderate” transition and 4 mmol·L−1 (LT2) for the “moderate” to “high” transition. Numerous studies show that VT2 is equivalent to LTHR/FTP for most athletes which they can find with field testing. On the other hand Maud and Foster note in Physiological Assessment of Human Fitness that numerous studies have failed to correlate a heart rate protocol to LT1/VT1 . Currently, the only known way to truly find this transition point is through lactate or VO2Max testing.

Subject matter experts and books on the subject such as Joe Friel's Training Bible, Allen Hunter’s Training and Racing with a Power Meter, and others like Gordon Bryn’s Going Long have become gold standards for defining training zones and intensity prescription, but across these experts there is no agreement on what "low" intensity truly is within their zones, The latest edition of the Training Bible uses Lactate Threshold Heart Rate (LTHR) minus 30 as an upper limit estimate for “low” intensity and a 3 on the Perceived Exhaustion Scale (RPE). This is of interest because an RPE of 3 and a HR Zone 1 are not the same.

On his blog Joe Friel describes “low” as what you would use for recovery or his heart rate Zone 1. HIs rule of LTHR - 30 does put most athletes within his heart rate Zone 1, but his colleague, Dr. Andrew Coggan, notes on the TrainingPeaks blog that power Zone 2 is the "forever" zone and that little to no training benefits are derived at Zone 1. This leaves the "low intensity "sweet spot" somewhere at the upper levels of heart rate Zone 1 which will overlap with Zone 2 by power/pace for most athletes.

This highlights why studies have been on world class athletes to determine time at "low" intensity over age group athlete. Doing a data scrub of training logs requires knowing the athlete's lab based VT1/LT1 which many non-elite athletes wouldn't have. This has changed recently for the masses though with the BSX Lactate Sensor (0ur readers get 15% off the BSX using coupon code: YN44EGW205617) and the prevalence of sub-maximal VO2Max testing taking place at gyms and studios.

In lieu of a BSX sensor or going to a lab for blood work the recommended current field tests are the “nose test” and LTHR - 30. For the nose test athletes should work just below the intensity where they can no longer breath strictly through their nose which is a body marker for VT1 and compare this HR and where the breathing transitions on an LSD sessions to find an indicator of the “low” to “moderate” transition point. The next step is to monitor the average percentage of FTP and FTPa to determine “low” training metrics.

This will likely mean living in the upper end of Zone 1 by heart rate the majority of the time and developing a feel for where this translates to power and pace. The good thing is that even in trained athletes this type of training still improves plasma volume and metabolic efficiencies and keeps the body fresh for the hard sessions. Experienced athletes should do the bulk of their other training at high intensity which has been shown to improve time to exhaustion, VO2Max, and running economy while addressing limiters with a mix of training as needed. Beginner and intermediate athletes will still show benefits with spending some of their hard days doing moderate training which is shown to improve endurance performance in untrained athletes.

The silver lining if undergoing lab testing is that, unlike Functional Threshold Power or Functional Threshold Pace, the heart rate associated with LT1/VT1 and LT2/VT2 are unlikely to change in trained athletes over time; defined by athletes with four or more consistent years in their sport. Thus, while it would require lab testing to determine the FTP equivalent for “low” every 6-8 weeks an athlete can continue to monitor their polarity in training based on heart rate and associate it to a given power over time. When in doubt, use heart rate and perceived effort on your "low" easy days as the best metric of keeping the overall stress on the body down so that you can reap the benefits of training hard on your "high" days.

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About the Author

Coach Dave is a USAT, USAC, and IRONMAN Certified Coach and has been coaching triathletes since 2016. Coach Dave believes an athlete centric coaching process backed by science and data. Coach Dave is the head coach of Triple Victor Racing and under his guidance these athletes worked throughout the season to reach a top team ranking with IRONMAN of 7th in the world. Coach Dave is a 9x time 70.3 and 6x IRONMAN finisher to include racing at the IRONMAN 70.3 World Championships in 2015 and 2016. Coach Dave is a 4x IRONMAN All-World Athlete, 2x USAT All-American and is ranked #1 in his state for Age Group 30-34. Coach Dave's athletes have raced around the world at every distance and he takes great pride in helping his athletes achieve in endurance athletics. You can learn more about Triple Victor Coaching here.

*The purpose of this article is not to be a general review that is applicable to the endurance athlete and is not meant to take the place of professional coaching or training.

#FTP #LTHR #HeartRate #Intensity