In recent months, we have received many questions about what Heart Rate Max value to use when setting up a Phlex account. Phlex currently bases training zones and monitors your progression based on your HRmax value, so it is important to set this value correctly. Using your individualized HRmax to set up your training zones will help you to train more effectively and efficiently, and to improve your performance over time. How to do it, we will discuss in this blog.

In our continuous journey to enhance swim training through Phlex, a prevalent inquiry has surfaced regarding the precise Heart Rate Max (HRmax) value to utilize when configuring a Phlex account. The essence of this question permeates the core of training efficacy and progression monitoring, given that Phlex rigorously bases training zones and tracks your evolution on this pivotal HRmax value.

Deciphering Max Heart Rate

The initial setup of your Phlex account employs a traditionally predictive calculation for HRmax: 207−(0.7×age). For a 16-year-old, this posits an estimated HRmax of 196. However, the intrinsic issue with such a predictive approach is the broad brush it paints for all individuals of the same age, overlooking the granularity and diversity of HRmax values amidst them.

The equation can't account for the nuance of an individual swimmer, so Phlex recommends calibrating your HRmax. As shown in the table below, four swimmers of the same age can have very different HRmax values. Additionally, HRmax is sport-specific, so the value you achieve in running or cycling may not be the same as the value you achieve in swimming. Swimming tends to elicit lower HRmax values compared to running due to factors such as the body being in a horizontal position, changes in hemodynamics, and the lack of a stable medium to push against.

How to find your Individualized HRmax

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1) RECOMMENDED: The Phlex Step Test Set

The most nuanced and scientifically backed strategy involves a step test, commencing with a pace marginally below your anaerobic threshold and methodically subtracting 2 seconds per 100 meters until peak velocity is reached. This highest HR during the test serves as an estimated HRmax.

• 15-seconds rest interval
• Swimmers encouraged to use primary competitive stroke

Detailed guide on how to run the Phlex Step Test below.

2) Time Trial All-Out Effort (3-Minute Test)

A 3-minute, all-out effort should theoretically nudge you towards your max heart rate value. Synchronizing this workout and noting the max HR from this exertion provides another methodology. These tests are typically done with a sports scientists on deck for properly assessing different data points that are all automatically measured by Phlex now.

Note: this method is very difficult and only recommended for the highest level swimmers, not practical for all skill levels.

3) Highest Recorded HR from Training History

Scouring through your training history and filtering by max HR within the Phlex platform will unveil the peak HR achieved across all workouts, offering a glimpse into your potential HRmax.

4) Real World Race Data

Racing with a Phlex tracker under your cap in a race exceeding 100 meters can yield valuable data, allowing you to gauge and record your HRmax during competitive scenarios.

Alternatively, your maximal score from racing an event, typically necessitating a distance greater than 100 meters, can be utilized. You can typically measure a great HRmax as you stretch the athletes output during the race.

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Here is an example of an athletes heart rate during a 500 freestyle competition.

The Phlex Step Test

Introduction

• Purpose: To provide swimmers with a methodical approach to accurately identify their Heart Rate Max (HRmax) through the Phlex Step Test Set.
• Significance: Establishing an authentic HRmax is pivotal in configuring precise training zones and enhancing swim training efficacy on the Phlex platform.

Objective of the Phlex Step Test Set

• Primary Goal: To achieve a reliable HRmax reading.
• Secondary Goal: To facilitate training at optimal zones by adding valuable training zone data to your profile to help avoid overestimations or underestimations of HRmax and correlated paces.

Prerequisites

• Phlex Tracker: Ensure it's fully charged and properly fitted to the swimmer as the heart rate data is critical.
• Phlex Account: Ensure the swimmers profile is established and they are syncing workouts correcty..
• Training Zone Chart: Familiarize yourself with the current recommended training zones. Note: If you see dramatic discrepencies in your training zone, we recommend using your discretion for the starting pace.
• Environment: Choose a controlled swimming environment to minimize variables during the test set.

Phlex Test Step by Step

Establishing a Starting Point

• Identify the swimmer’s anaerobic threshold pace using the Phlex training zone chart.
• E.g., For a youth breaststroker, starting at 1:30/29 per 100 m.

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Designing the Step Test

• Execute a series of 6x100 swims. If you can go faster after 6, swimmer likely didn't achieve HRmax
• Enforce a rough 15-second interval between each 100 m. The key is to not let the swimmers dip below aerobic or anaerobic capacity during the set.

Executing the Set

• Begin swimming at the identified anaerobic threshold pace.
• Descend 2 seconds per 100 m from the initial pace.
• 15-seconds rest interval
• Continue until the swimmer can no longer maintain the decremented pace or fails to complete the 100 m within the prescribed time.

Recording and Analyzing

• Utilize the Phlex device to record HR, stroke and lap data throughout the set.
• Identify the peak HR achieved during the set - this serves as the estimated HRmax.

Real World Swimmer Example

• Swimmer Profile: A 15-year-old youth breaststroker.
• Execution:
• Initial Pace: 1:30/29 per 100 m.
• Deducted 2 seconds per 100 m until failure.
• Outcome: Maximal HR registered was 191 bpm.
• Comparison: Predictive equation suggested 197 bpm, illustrating the nuanced accuracy of the Phlex Step Test.

Using your individualized HRmax to set up your training zones will help you to train more effectively and efficiently, and to improve your performance over time. By training in the right zones, you can target specific physiological adaptations, such as increasing your aerobic capacity or improving your lactate threshold.

Benefits of using Individualized HRmax

The Phlex Step Test Set, while being a meticulous and methodical approach to discerning an athlete's Heart Rate Max (HRmax), transcends mere numerical discernment and extends its utility into several facets of swim training optimization.

1. Achieving Training Precision

• Tailoring to Individual Needs: The derived HRmax provides a fine-tuned metric, bespoke to the athlete’s current physiological status, thereby guiding training zones that are inherently individualized.
• Mitigating Generalization: This eliminates the risk of employing generalized predictive equations, which may inadvertently misalign training efforts due to overestimations or underestimations of true HRmax.‍
• Strategic Zone Training: Harnessing an accurate HRmax enables athletes to train within zones that precisely target and stimulate desired physiological adaptations, whether it be enhancing aerobic or anaerobic capacity or improving lactate threshold.‍
• Data-Driven Adjustments: The meticulous data derived allows for a strategic pivot in training approaches, ensuring that every swim session is optimally aligned with the athlete’s physiological capabilities and goals.

2. Enhancing Performance Monitoring

• Monitoring Progression: Employing a genuine HRmax within the Phlex platform enables a more authentic tracking of progression, as training zones and subsequent efforts are rooted in actual physiological metrics.
• Identifying Plateaus or Advancements: With precise training zones, athletes and coaches can promptly identify areas of stagnation or progression, thereby allowing for timely modifications in training strategies.‍
• Temporal Analysis: By conducting the Phlex Step Test periodically, swimmers and coaches can perform a robust comparative analysis of HRmax over time, enabling insights into the athlete’s evolving fitness and capabilities.
• 7-Day vs. 30-Day Insights: Notably, comparing the data from a swimmer’s 7-day and 30-day HRmax post-test can unveil interesting narratives about their training:
• Short-Term Analysis: A 7-day analysis post-test provides immediate feedback on the immediate impact of the set and could indicate the acute responses and recovery of the athlete.
• Adaptation Insights: Conversely, evaluating the 30-day data sheds light on the longer-term adaptations and potential fitness shifts, offering a wider lens through which to evaluate and strategize training.

Conclusion

The pursuit of your genuine HRmax stands as a cornerstone in establishing your training zones and propelling towards your swimming objectives. Though we have presented multiple methodologies, we recommend using the Phlex Step Test for proper calibration.

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