GUEST SERIES | Dr. Andy Galpin: How to Build Physical Endurance & Lose Fat
Dr. Andy Galpin, PhD, professor of kinesiology, details protocols for four types of physical endurance: muscular, anaerobic, maximum aerobic, and long-duration. He clarifies fat loss mechanisms, emphasizing carbon exchange and metabolic flexibility for optimal performance and health.
Deep Dive Analysis
16 Topic Outline
Defining Endurance and Its Broad Applications
Quick Endurance Boosters: Mechanics and Exercise Snacks
Categories of Endurance: From Daily Energy to Marathons
Fat Loss Mechanism: The Carbon Cycle and Respiration
Exercise Intensity, Fuel Utilization, and Fat Loss Misconceptions
Metabolic Flexibility: Optimizing Fuel Source Utilization
Assessing and Improving Metabolic Flexibility
Cellular Energy Production: Anaerobic vs. Aerobic Metabolism
Lactate: Not a Cause of Fatigue, but a Fuel and Buffer
Fuel Sources and Exercise Intensity: Phosphocreatine, Carbs, Fat, Protein
Muscular Endurance: Training for Localized Fatigue Management
Anaerobic Capacity: High-Intensity Work and Waste Clearance
Breathing Gear System for Exercise Intensity Assessment
Maximum Aerobic Output: Training for 5-15 Minute Peak Performance
Long Duration Endurance: Sustained Effort and Diaphragmatic Fatigue
Combining Endurance Training for Overall Fitness and Longevity
8 Key Concepts
Endurance
Endurance is fundamentally about fatigue management and fueling. It encompasses various abilities, from maintaining daily energy and posture to performing repeated small efforts (muscular endurance), maximal efforts for short durations (anaerobic capacity), sustained efforts for several minutes (maximum aerobic output), and very long durations (long duration endurance).
Fat Loss Mechanism
Fat loss primarily occurs through respiration, where stored carbon molecules from fat are broken down, combined with oxygen, and exhaled as carbon dioxide (CO2). This process is part of the body's carbon cycle, where ingested carbon (from food) is either stored or expelled, and a caloric deficit leads to the mobilization and exhalation of stored carbon.
Metabolic Flexibility
Metabolic flexibility refers to the body's ability to efficiently switch between different fuel sources (carbohydrates and fats) depending on availability and demand. It's not about maximizing fat burning, but rather optimizing the utilization of the most appropriate fuel source for a given activity or state, ensuring stable energy levels throughout the day.
EPOC (Excess Post-exercise Oxygen Consumption)
EPOC is the elevated oxygen consumption that occurs after exercise, particularly high-intensity exercise. It represents the body's effort to 'pay back' an oxygen debt incurred during intense activity, where waste products accumulated faster than they could be cleared, requiring continued ventilation even after the exercise stops.
Lactate
Lactate is a molecule produced during anaerobic glycolysis, often associated with muscle fatigue or 'the burn.' However, it's not the cause of fatigue but rather a buffer that helps manage acidity (free-floating hydrogen ions) and can be used as a potent fuel source by various tissues, including the heart and liver, or converted back into glucose.
Anaerobic Glycolysis
This is the initial, oxygen-independent phase of carbohydrate metabolism that occurs in the cytoplasm of muscle cells. It rapidly breaks down glucose (a six-carbon chain) into two three-carbon pyruvate molecules, producing a small amount of ATP quickly, but also generating waste products like hydrogen ions (acidity) that need to be buffered, often by forming lactate.
Aerobic Metabolism
This is the oxygen-dependent phase of energy production that occurs in the mitochondria. It fully metabolizes carbohydrates (after anaerobic glycolysis) and is the sole pathway for fat and protein metabolism. This process, including the Krebs cycle and electron transport chain, generates a large amount of ATP, water, and carbon dioxide (CO2) from fuel sources.
Capillarization
Capillarization is the increase in the density of capillaries (tiny blood vessels) surrounding muscle fibers. This adaptation improves the delivery of oxygen and nutrients to working muscles and enhances the removal of waste products like CO2 and acid, thereby improving muscular endurance and overall fatigue management.
12 Questions Answered
Endurance is the ability to manage fatigue and fuel effectively. It includes maintaining daily energy, muscular endurance (repeated small efforts), maximum anaerobic capacity (20-80 second maximal efforts), maximum aerobic capacity (5-15 minute maximal efforts), sustained position, and long-duration endurance (extended activities like hiking).
The quickest way to improve endurance is by enhancing mechanics, starting with proper breathing techniques (often nasal breathing) and posture, followed by refined movement technique, as efficiency trumps force for endurance.
The body loses fat by exhaling carbon. Fat molecules, which are chains of carbon, are broken down during metabolism, and the resulting carbon combines with inhaled oxygen to form carbon dioxide (CO2), which is then expelled through breathing.
Yes, technically, increasing exhalation rate directly expels more carbon, which is how fat leaves the body. However, simply hyperventilating is not a sustainable or healthy strategy; effective fat loss requires increasing the demand for energy through exercise, which naturally increases respiration and carbon output over time.
No, training fasted or at a lower intensity 'fat-burning zone' does not inherently enhance overall fat loss. While lower intensity exercise burns a higher *percentage* of fat during the activity, total caloric expenditure is low. Overall fat loss depends on total carbon (calorie) deficit over time, regardless of the fuel source used during exercise.
When high-intensity exercise burns a lot of muscle glycogen (carbohydrates), the body prioritizes replenishing those carbohydrate stores from ingested food. In a caloric deficit, this means that the body will then mobilize and utilize stored body fat for its general energetic needs, leading to fat loss.
No, muscle cannot turn into fat, and fat cannot turn into muscle. They are distinct tissue types with different structures and metabolic functions. While the body can convert carbohydrates into fat for storage, and in some cases, protein can be used to make glucose, these are not direct conversions between muscle and fat tissue.
Metabolic flexibility can be assessed by observing energy regulation throughout the day, blood glucose levels (ideally 85 mg/dL or lower), and practical performance tests. For example, if you can perform a standard fasted workout with little drop in performance, or if you don't 'bonk' or feel sleepy after a reasonable carbohydrate meal, these are signs of good metabolic flexibility.
For 0-15 seconds of maximal exertion, phosphocreatine is the primary fuel. For 15 seconds to a few minutes, anaerobic glycolysis (carbohydrates) predominates. For longer durations (5 minutes to ultramarathons), aerobic metabolism uses a mix of carbohydrates and fats, with carbohydrates often still being the primary fuel for high-intensity endurance, and fat becoming more significant in very long, lower-intensity efforts.
Lactate is produced when anaerobic glycolysis generates pyruvate faster than it can be processed by the mitochondria, leading to a buildup of hydrogen ions (acid). Lactate acts as a buffer, binding to these hydrogen ions to prevent excessive acidity, and can also be used as a valuable fuel source by other tissues or converted back to glucose.
Muscular endurance training, involving repeated efforts to near failure in local muscle groups (e.g., push-ups, planks), primarily improves the body's ability to buffer acid buildup and increases capillarization. This enhanced blood flow and waste removal allow muscles to sustain effort longer without excessive fatigue.
A 'gear system' can be used: Gear 1 (Zone 1) is nasal breathing at a set cadence (e.g., 2-3 sec inhale/exhale). Gear 2 (Zone 2) is nasal breathing at whatever rate needed, but mouth remains closed. Gear 3/4 (Zone 3-5) involves nose-to-mouth or pure mouth breathing, indicating higher intensity where nasal breathing alone is insufficient for oxygen intake/CO2 offload.
43 Actionable Insights
1. Manage Carbon Exchange for Fat Loss
Understand that fat loss fundamentally relies on ingesting less carbon (calories in) or expelling more carbon (calories out), as fat is primarily lost through respiration as CO2.
2. Prioritize Adherence for Fat Loss
For fat loss, choose any exercise strategy (high intensity, steady state, etc.) that you can consistently adhere to over time, as the specific mode of carbon expenditure is less critical than total output.
3. Train Across Full Spectrum
To maximize longevity, performance, and aesthetics, incorporate a full spectrum of training, including both steady-state long-duration and higher-intensity interval training, rather than choosing just one.
4. Implement “Exercise Snacks”
Perform short (e.g., 20-second) bouts of all-out exertion, like running stairs, multiple times a day (e.g., every four hours, three times a week) to improve cardiorespiratory fitness, VO2 max, cognitive benefits, and postprandial glucose control.
5. Frequent Short Exertions
Regularly engage in short, all-out bursts of activity (e.g., 10-30 seconds, multiple times a day) to quickly elevate heart rate, without needing a warm-up or causing significant sweating, for similar benefits to structured “exercise snacks.”
6. Improve Mechanics for Endurance
Focus on improving breathing techniques, posture, and movement technique as the quickest way to enhance endurance, as efficiency trumps force for repeated performance.
7. Use Nasal Breathing
Practice nasal breathing during exercise, as it often helps correct breathing mechanics by default and is a quick way to improve endurance.
8. Maintain Upright Posture
Ensure proper posture during all activities, including exercise, by being more upright to prevent loss of efficiency and potential injury over time.
9. Develop Strategic Breathing
Adopt a more strategic breathing pattern during exercise to avoid over-breathing early on, which can lead to problems and fatigue later.
10. Monitor Resting Heart Rate
Aim to lower your resting heart rate to sub-60 beats per minute as a positive adaptation to endurance training, indicating improved cardiovascular efficiency.
11. Combine Hypertrophy & Muscular Endurance for Fat Loss
For optimal fat loss, incorporate resistance training in the hypertrophy to muscular endurance range (6-30 repetitions) to deplete muscle glycogen, which indirectly promotes fat utilization.
12. Aim for Lower Fasting Blood Glucose
Strive for a fasting blood glucose level of 85 mg/dL or lower, as levels above 85 mg/dL are associated with an increased likelihood of developing type 2 diabetes.
13. Monitor ALT/AST Ratio
Check your ALT/AST ratio, aiming for a value lower than 0.8, as an elevated ratio can be a clue for blood glucose dysregulation, though not a definitive diagnostic.
14. Assess Fasted Exercise Performance
Regularly perform a standard workout fasted; if you experience little to no drop in performance, it suggests good fat utilization as a fuel source.
15. Test Carbohydrate Tolerance
Observe your energy response after consuming ~50 grams of carbohydrates; experiencing a significant energy crash 30 minutes later may indicate poor carbohydrate utilization.
16. Improve Carb Utilization with High-Intensity Training
To enhance carbohydrate utilization, engage in higher-intensity training sessions after consuming carbohydrates, which helps the body become more efficient at using them as fuel.
17. Improve Fat Utilization with Pre-Workout Fat or Fasted Training
To improve fat utilization, consume fat before a workout (though this may slightly reduce peak performance) or incorporate fasted training, as both strategies encourage the body to adapt to using fat as a primary fuel source.
18. Stabilize Protein and Fiber Intake
Ensure consistent and adequate protein intake, and combine carbohydrates with fiber and/or protein to stabilize blood glucose and improve overall energy regulation throughout the day.
19. Exercise Before Cognitive Tasks
Perform a 20-minute bout of exercise prior to mentally demanding tasks like exams to potentially increase cognitive performance and exam scores, likely due to factors like elevated lactate.
20. Lactate Is Fuel Not Waste
Understand that lactate acts as an acid buffer and a potent fuel source, not just a waste product, and can be recycled into glucose or used by other tissues like the heart.
21. Precision in Muscular Endurance Exercise
Select exercises that precisely target the muscle groups and movement patterns you wish to improve, as muscular endurance training is highly specific (e.g., do planks to improve plank hold time).
22. Train to Failure for Capillarization
To increase capillarization and enhance muscular endurance, train specific muscle groups close to failure frequently, as this increases local blood flow and stimulates capillary growth.
23. Use Light Load for Muscular Endurance
For muscular endurance, use a light load (e.g., 50-60% of 1RM) that allows for high repetitions (15+ reps) to train within the desired repetition range, as heavy loads shift focus away from endurance.
24. Frequent Muscular Endurance Training
Perform muscular endurance training (e.g., 2-3 sets to near failure) frequently, such as three to four times a week per muscle group, due to the light load and lower soreness compared to hypertrophy training.
25. Progressive Overload for Muscular Endurance
Progress muscular endurance by adding one or two repetitions or a small amount of time to your sets each week; if progress stalls, reduce intensity and accumulate more practice at 80-85% of your max.
26. Choose Safe Anaerobic Exercises
Select exercises for anaerobic capacity that are safe and familiar (e.g., assault bike, rower, uphill sprints) to minimize injury risk and allow maximal focus on exertion and form during high-intensity efforts.
27. Anaerobic Capacity Workouts
Perform anaerobic capacity training (e.g., 30 seconds on, 30 seconds off) for a minimum of four rounds, at least once or preferably twice a week, aiming to reach maximum heart rate during the work intervals.
28. Optimize Rest for Anaerobic Quality
For short, all-out bursts (e.g., 20 seconds), use a higher rest-to-work ratio (e.g., 2:1 or 40-60 seconds rest) to ensure extremely high quality and maximal effort during each work interval.
29. Target 5-6 Minutes All-Out Anaerobic Work
Aim for 5-6 minutes of total all-out anaerobic work per week, distributed across 2-3 workouts, using bouts of 20-60 seconds with sufficient rest between rounds to maintain high quality.
30. Use the “Sugar Cane” Protocol
Perform a 3-round interval protocol: 1) Max distance in 2 mins, 2) Rest 2 mins, 3) Cover Round 1 distance, noting time, 4) Rest 2 mins, 5) Work for Round 2’s time, aiming for more distance than Round 1. This challenges pacing and recovery.
31. Progressive Overload for Anaerobic Capacity
Progress anaerobic capacity by increasing total work (e.g., 5% more distance/reps) each week, or by adding rounds to your interval protocols over time.
32. Weekly Max Aerobic Output Test
Perform a maximal aerobic output test, such as a one-mile run as fast as possible (5-10 minutes for most), once a week to improve this capacity.
33. Include Moderate Intensity Support Work
Supplement maximal aerobic output training with moderate-intensity support work (e.g., 40% of total training time, heart rate below 85% max but above conversational pace) to improve oxygen transport and capillarization without over-fatigue.
34. Distribute Max Aerobic & Anaerobic Work
Integrate maximal aerobic output and anaerobic capacity training by dedicating one day to shorter, high-intensity intervals and another day to a 5-15 minute maximal effort, ensuring both high-intensity domains are covered weekly.
35. Use Circuits for Long Duration Endurance
Create circuits of various exercises (e.g., farmer’s carries, planks, bodyweight squats, jump rope) with minimal rest between movements to achieve long-duration endurance benefits without repetitive, mind-numbing activities like continuous running.
36. Minimum Weekly Steady-State Endurance
Incorporate at least 20-30 minutes of steady-state endurance exercise once a week, as it provides significant benefits for various training goals, including capillarization and fat utilization.
37. Train Breathing Musculature
To prevent fatigue of the intercostal muscles and diaphragm during long-duration exercise, incorporate breathing drills or use specialized lung exercise devices.
38. Monitor for Technical Breakdown
During endurance training, use technical breakdown (loss of good form or posture) as a key marker for when to stop or reduce intensity, as it indicates fatigue and loss of efficiency.
39. Weekly Long Duration Endurance Volume
Aim for 60-120 minutes of long-duration endurance work per week, which can be done in one longer session (e.g., a weight-vested hike) or split into two shorter sessions (e.g., 45 minutes each).
40. Use Long Cool-Down for Recovery
After high-intensity workouts, perform a 20-30 minute slow cool-down, including 3-5 minutes of slow nasal breathing (e.g., 4-5 second inhale/exhale), to aid down-regulation and recovery.
41. Structure Endurance Training (70/10/20 Rule)
For endurance goals (e.g., half marathon), allocate 60-70% of training to moderate intensity (tempo/practice), 10% to short (20-second) high-intensity bursts, and 20-30% to 5-15 minute maximal efforts (repeated intervals), to build comprehensive endurance.
42. Incorporate Tempo Training
Include tempo training (60-80% effort, faster than conversational pace but not maximal sprint) to practice race-specific skill, accumulate mileage, and build work capacity for endurance events.
43. Distribute Endurance Work Across Week
For a 4-day-a-week endurance program, dedicate two days to moderate-intensity tempo training, one day to short (20-30 second) high-intensity bursts, and one day to a maximal aerobic output effort (e.g., VO2 max training).
8 Key Quotes
Endurance really comes down to two independent factors. Factor number one is fatigue management. And then factor number two is fueling.
Dr. Andy Galpin
The quickest way to improve endurance is to improve mechanics. And the mechanical thing I would go after first is your breathing techniques, your pattern, your entire approach, as well as your posture.
Dr. Andy Galpin
The only reason you bring in O2 for the most part is to get rid of the CO2. Oxygen is not a fuel source. It is not a way.
Dr. Andy Galpin
People always say calories in, calories out. It's really carbon in, carbon out. That's what a calorie is, right?
Dr. Andy Galpin
Maximizing fat burning and maximizing fat for exercise and maximizing fat loss over time are not the same thing at all, right? That's the confusion.
Dr. Andy Galpin
Your carbohydrates are meant to be incredibly flexible. It is the primary fuel source for a reason. Your fat is not meant to be flexible. It is meant to be unlimited.
Dr. Andy Galpin
Lactate is a tremendously valuable fuel source, not only for exercise, but for cognition and a bunch of other things.
Dr. Andy Galpin
Protein is a fuel source for exercise or metabolism, it's just an incredibly poor choice. Your body does not want to do it. You're not good at it.
Dr. Andy Galpin
6 Protocols
Exercise Snacks for Endurance and Metabolic Health
Dr. Andy Galpin- Perform a 20-second bout of all-out exertion (e.g., running up stairs, burpees, jumping jacks).
- Repeat this bout approximately once every four hours throughout the day (e.g., upon arrival at work, at lunch, before leaving work).
- Aim for multiple times a week (e.g., 3 times a week for 6 weeks) to improve cardiorespiratory fitness (VO2 max) and cognitive benefits, and to improve postprandial glucose control after high glycemic index meals.
Muscular Endurance Training
Dr. Andy Galpin- Select specific exercises targeting the muscle groups you want to improve (e.g., push-ups, wall sits, planks, pull-ups).
- Use a load that allows for high repetitions (e.g., 50% of 1-rep max or bodyweight) to train in the 15-50+ rep range.
- Perform sets close to failure or until technical breakdown, focusing on increasing capillarization and acid buffering.
- Repeat these sessions frequently, such as 3-4 times per week per muscle group, as the low load allows for quicker recovery.
- Progress by adding 1-2 repetitions or a few seconds of duration per week, or by accumulating more practice at 80-85% of max effort.
Anaerobic Capacity Training (High-Intensity Intervals)
Dr. Andy Galpin- Choose safe, total-body exercises that minimize eccentric load and allow for maximal effort without technical breakdown (e.g., assault bike, rower, uphill sprints, swimming, sled pushes/drags).
- Perform all-out efforts in the 20-90 second range.
- Follow each effort with sufficient rest (e.g., 1-3 minutes for 60-second efforts, 40-60 seconds for 20-second efforts) to ensure high quality of subsequent rounds.
- Aim for 4-6 rounds per session, 1-2 times per week, to accumulate 5-6 minutes of total all-out work per week.
- Progress by increasing distance/work done in the same time, or by adding rounds over several weeks (e.g., 3 rounds in week 1, 4 in week 2, etc.).
Sugarcane Endurance Protocol (Anaerobic Capacity)
Kenny Kane (described by Dr. Andy Galpin)- Perform a maximal effort for 2 minutes on a measurable distance machine (e.g., air bike, rower, treadmill), covering as much distance as possible. Note this distance (e.g., 400 meters).
- Rest for 2 minutes.
- In the second round, cover the *exact same distance* (e.g., 400 meters) as round one, regardless of how long it takes (it will likely take longer due to fatigue).
- Rest for 2 minutes.
- In the third round, perform the exercise for the *exact same duration* as round two (e.g., 2 minutes and 5 seconds) and try to cover a greater distance than round one (e.g., 405 meters).
- This protocol ensures that slacking in any round makes subsequent rounds harder, promoting consistent maximal effort.
Maximum Aerobic Output Training
Dr. Andy Galpin- Select an exercise that allows for sustained maximum intensity for 5-15 minutes without technical breakdown (e.g., a one-mile run, sustained fast rowing/cycling).
- Perform this maximal effort 1-2 times per week.
- Progress by trying to cover more distance in the same time or reduce the time to cover the same distance.
- Supplement this with 40% of your total endurance training time dedicated to lower-intensity support work (e.g., 70-85% of max heart rate), focusing on capitalization and oxygen transport without full exertion.
Long Duration Endurance Training
Dr. Andy Galpin- Engage in activities that can be sustained for 20-120 minutes at a moderate intensity (e.g., brisk walking, hiking, cycling, swimming, circuit training with light loads/bodyweight).
- Focus on maintaining good posture and breathing mechanics throughout the session, as diaphragmatic fatigue can become a limiting factor.
- Aim for 60-120 minutes of this work per week, which can be done in one longer session or split into shorter ones (e.g., two 45-minute sessions).
- Consider incorporating varied movements (e.g., farmer's carries, planks, bodyweight squats in a circuit) to maintain engagement and functional fitness.
- Progress by gradually increasing duration or slightly increasing intensity while maintaining the ability to converse (Zone 2-3 equivalent).