How much Zone 2 exercise should I do per week?

Peter Attia recommends a target of at least three hours of Zone 2 training per week. For individuals new to exercise or significantly deconditioned, starting with 30 minutes, three times a week may be appropriate.

What are the main benefits of Zone 2 training?

Zone 2 training is crucial for enhancing mitochondrial function, which is key to healthy aging and metabolic health. It improves the efficiency of glucose disposal, increases insulin sensitivity, and may help combat processes involved in inflammation.

Can I do Zone 2 exercise after strength training?

While possible, doing Zone 2 immediately after intense strength training might be counterproductive for hypertrophy or strength gains. It's generally recommended to separate these sessions by several hours or perform Zone 2 first if time is limited.

How do I accurately measure my Zone 2 intensity if I don't have a lactate meter?

Without a lactate meter, you can triangulate using heart rate and perceived exertion. Aim for approximately 80% of your actual maximum heart rate. You should be able to mostly nasal breathe and hold a conversation, though it may feel slightly uncomfortable.

Does my Zone 2 threshold change as I get fitter?

Yes, your Zone 2 threshold should increase as you improve your fitness. This is an aspiration; as your aerobic capacity grows, you'll be able to produce more power (watts per kilo) before lactate levels rise above 2 millimoles.

Is Zone 2 training better than HIIT?

Zone 2 and HIIT serve different physiological purposes. Zone 2 optimizes mitochondrial health and metabolic efficiency, while HIIT targets other systems. They are not directly comparable and can both be beneficial parts of a training regimen.

Can I do Zone 2 exercise on a treadmill?

Yes, you can perform Zone 2 on a treadmill by using incline rather than just speed. A brisk walk at a significant incline (e.g., 6% with a brisk pace) can help reach the appropriate intensity, aiming for at least 15 minutes of steady state before assessment.

Key Moments

Q&A on Zone 2 Exercise with Peter Attia, M.D.

Peter Attia MD

People & Blogs4 min read56 min video

Apr 21, 2021|577,061 views|9,729|500

Save to Pod

Key Moments

TL;DR

Peter Attia defines and explains Zone 2 exercise, emphasizing its importance for mitochondrial health and metabolic function.

Key Insights

Zone 2 exercise is defined physiologically as the highest energy output while keeping blood lactate below 2 millimolar, crucial for mitochondrial optimization.

Regular Zone 2 training enhances mitochondrial function, which is a key factor in combating aging and improving metabolic health.

The optimal duration and frequency of Zone 2 training vary based on fitness levels, with a target of at least 3 hours per week, ideally in 45-minute sessions.

Zone 2 training should be performed with precise control over intensity, often indoors on a bike or treadmill, to avoid slipping into higher intensity zones.

While not a direct replacement for High-Intensity Interval Training (HIIT), Zone 2 training complements it by targeting different physiological pathways and promoting insulin sensitivity.

Monitoring Zone 2 can involve using a lactate meter for precision, but heart rate and perceived exertion are viable alternatives.

DEFINING ZONE 2 EXERCISE

Peter Attia clarifies that Zone 2 exercise is not defined by arbitrary heart rate percentages or power outputs, but rather by a specific physiological and cellular metric: the highest level of energy output achievable while maintaining blood lactate levels below 2 millimolar. This threshold indicates that the body's mitochondria are operating efficiently, efficiently converting fuel into ATP without generating excessive lactate as a byproduct. Exceeding this level signifies that the body is relying on less efficient energy production pathways outside the mitochondria.

THE PHYSIOLOGICAL IMPORTANCE OF ZONE 2

The primary benefit of Zone 2 exercise lies in its profound impact on mitochondrial health. Attia posits that enhancing mitochondrial function and delaying their deterioration, a hallmark of aging, is paramount. By training within Zone 2, individuals optimize their mitochondria's ability to efficiently process glucose and fatty acids, leading to improved insulin sensitivity and overall metabolic health. This is contrasted with individuals with poor metabolic health who have a much lower Zone 2 threshold compared to elite athletes.

OPTIMAL FREQUENCY AND DURATION

The recommended frequency for Zone 2 training is typically three to four hours per week, though this can be adjusted based on individual fitness. Beginners might start with 30 minutes, three times a week, gradually increasing to 45-minute sessions. Elite athletes dedicate significantly more time, potentially 20-24 hours per week during training seasons. Attia emphasizes that longer, sustained sessions are generally more effective than multiple short bursts, as it takes time to achieve a steady state within Zone 2.

EXECUTION AND MONITORING

Precise control over intensity is crucial for Zone 2 training, making indoor exercise on a bike or treadmill often preferable. This allows for consistent wattage or speed maintenance, preventing accidental excursions into higher heart rate zones (Zone 3-5) which produce more lactate. While a lactate meter provides the most accurate measurement, Attia suggests that a combination of heart rate monitoring (around 80% of maximum heart rate, not predicted) and perceived exertion (ability to talk but not sing) can be effective proxies.

ZONE 2 IN RELATION TO OTHER TRAINING MODALITIES

Attia distinguishes Zone 2 training from High-Intensity Interval Training (HIIT), stating they serve different physiological purposes and are not mutually exclusive. While HIIT is easier to study due to its concise protocols, Zone 2 targets foundational metabolic health and mitochondrial efficiency. He advises against viewing it as an either/or decision, encouraging individuals to consider incorporating both types of training based on their specific goals, rather than making a false equivalency.

ADJUSTING ZONE 2 WITH FITNESS AND EXTERNAL FACTORS

An individual's Zone 2 threshold, often measured in watts per kilogram, measurably increases with improved fitness. Attia notes his personal Zone 2 wattage has increased over time. Factors like sleep, stress, and even recent meals can influence lactate levels and perceived exertion during Zone 2 exercise, highlighting the importance of listening to one's body. For individuals on Metformin, Attia observes it can lower Zone 2 thresholds, and he is funding research to investigate the true physiological impact on mitochondrial function.

ACTIVITY SPECIFICITY AND OTHER CONSIDERATIONS

Zone 2 can be specific to the activity performed; efficiency on a bike may not translate directly to a rowing machine. Attia suggests that swimming can be an effective modality for Zone 2 training due to the control over pace in a pool. He also touches on the role of Zone 1 (active recovery) and how Zone 2 training can improve deep sleep, though its direct impact on Heart Rate Variability (HRV) is less clear anecdotally. Fasted cardio is generally endorsed for Zone 2 if preferred, as it maximizes fatty acid availability.

Mentioned in This Episode

●Products

●Software & Apps

●Companies

●Studies Cited

●Concepts

●People Referenced

Zone 2 Exercise Cheat Sheet

Practical takeaways from this episode

Do This

Aim for a specific physiologic definition: highest energy output with lactate below 2 millimole.

Train 3-4 hours per week (3 hours target for patients).

Each session should ideally be 45 minutes long.

Use a method with precise power control (e.g., indoor bike trainer, treadmill with incline).

Focus on maintaining Zone 2 intensity to maximize mitochondrial benefits.

Consider separating Zone 2 and strength training by several hours on the same day if necessary.

If using heart rate, aim for 80% of actual maximum heart rate (not predicted).

Prioritize consistency, especially as you age, to maintain metabolic health.

Check lactate immediately post-workout if monitoring.

Warm-up on a treadmill with incline for at least 15 minutes before assessing Zone 2.

Wash hands with soap and water before testing lactate.

Track your Zone 2 power in watts per kilo as a key performance metric.

Consider Zone 1 for active recovery if truly fatigued.

Swim training can be effective for Zone 2 if pace is controlled.

Do Zone 2 in the morning, often fasted, for optimal glucose disposal.

Avoid This

Don't confuse Zone 2 with general heart rate zones (e.g., Garmin's 60-70%).

Avoid significantly exceeding 2 millimole of lactate during Zone 2 sessions.

Do not jump immediately into Zone 2 after intense strength training if hypertrophy or strength is the primary goal.

Avoid slipping frequently into Zone 3, 4, or 5 during a Zone 2 workout.

Don't rely solely on predicted maximum heart rate; determine your actual maximum.

Don't perform Zone 2 on activities where precise intensity control is difficult.

Do not assume Zone 2 is the same as Lactate Threshold or Functional Threshold.

Avoid waiting too long after finishing Zone 2 to check lactate levels.

Don't assume Zone 2 is easy; it requires consistent effort to stay within the defined parameters.

Do not ignore the activity-specific nature of Zone 2; progress may be slower if switching modalities frequently.

Do not aim for 3 millimoles of lactate, as this is generally considered unsustainable.

Don't expect Zone 2 to be a primary neuromuscular training stimulus.

Common Questions

Zone 2 exercise is defined physiologically as the highest level of energy output you can sustain while keeping blood lactate below 2 millimoles per liter. This indicates your body is efficiently producing ATP using mitochondria without exceeding their clearing capacity.

Topics

Endurance Training Exercise Physiology Metabolic Health Health & Longevity Neuroscience & the Brain Mitochondrial Health Aging Well Lactate Threshold Fitness & Exercise Aerobic Capacity

Mentioned in this video

Products

Wahoo KICKR

An indoor bike trainer that provides precise wattage information for Zone 2 training.

Novo Biomedical Lactate Plus

A lactate meter that Peter Attia uses but considers expensive and a 'ripoff'.

Oura Ring

A tracking device used by patients who have anecdotally reported increased deep sleep with Zone 2 training.

Continuous Glucose Monitor

Devices like those from Dexcom that are useful for tracking glucose, with potential application in optimizing Zone 2 for glucose disposal.

Garmin

A heart rate monitor brand whose Zone 2 settings are noted to differ from the physiologic Zone 2 definition discussed.

Dexcom

A company interested in providing access to Continuous Glucose Monitors (CGMs) for a wider audience.

Drugs & Medications

Metformin

A medication that Peter Attia states categorically lowers Zone 2 thresholds in patients, potentially by inhibiting mitochondrial complex 1.

Rapamycin

Peter Attia expresses positive feelings about this drug, stating he is 'loving every second of it'.

Ozempic

A GLP-1 agonist mentioned for its effectiveness in insulin sensitivity and weight loss, though it can cause initial low energy.

Studies & Research

Bruce Protocol

A 21-minute cardiac stress test protocol recommended for finding maximum heart rate, often used on treadmills.

People

Andrew Coggan

Developed a system of seven training zones based on Functional Threshold Power (FTP) used in cycling.

Iñigo San Millán

Mentioned as an expert on Zone 2 training, whose podcast recommendations are followed regarding session length.

Peter Attia

Host of the Q&A session discussing Zone 2 exercise.

Phil Maffetone

Mentioned for his 'MAFF' formula (180 minus age) as a starting point for heart rate zone calculations.

Concepts

Mitochondrial function

Key to aging and metabolic health; Zone 2 exercise is considered the most important training modality for improving mitochondrial function.

Functional Threshold Power

The maximum power a cyclist can sustain for one hour, used as a basis for training zones in cycling.

GLP-1 Agonist

A class of drugs, including Ozempic, that can cause low energy levels initially but tend to equilibrate over time.

DEXA Scan

A tool used to measure body composition, specifically focusing on lean mass, which is important for maintaining health with age.

Type 2 Diabetes

Mentioned as a condition that represents a failure of glucose disposal, contrasting with general age-related decline in glucose handling.

Ketogenic Diet

Mentioned as a contrast to fasting, highlighting how different dietary approaches yield different physiological states.

Insulin sensitivity

A key marker of metabolic health that is improved by Zone 2 exercise, making mitochondria more efficient at glucose uptake.

Supplements

reactive oxygen species

Damage caused by these species can be combated by improved mitochondrial function, a benefit of Zone 2 training.

Found this useful? Build your knowledge library

Get AI-powered summaries of any YouTube video, podcast, or article in seconds. Save them to your personal pods and access them anytime.

Try Summify free