Dr. Andy Galpin: How to Build Physical Endurance & Lose Fat

Types of Endurance and Fuel Systems

• Endurance comes down to two factors: 
  • Fatigue management
  • Fueling
• People exercise for three reasons: 
  • Feel better
  • Look a certain way
  • Perform a certain way for a long time

Quick Ways to Improve Endurance

• Improve mechanics and mechanical efficiency 
  • Breathing techniques and patterns
  • Proper posture and positions
  • Movement technique
• Nasal breathing can help improve breathing mechanics
• Train across the full spectrum of exercise, including steady-​​state and high-​​intensity interval training

Exercise Snacks

• Short, intense bouts of exercise can improve cardiorespiratory fitness and cognitive benefits
• Example: 20-​​second stair sprints repeated throughout the day
• Studies show significant improvements in VO2 max and work productivity after incorporating exercise snacks into daily routines

In summary, endurance is a combination of fatigue management and fueling. To improve endurance, focus on proper breathing, posture, and movement techniques. Additionally, incorporating a variety of exercise types, including steady-​​state and high-​​intensity interval training, can help maximize endurance adaptations. Finally, consider incorporating “exercise snacks” into your daily routine for quick improvements in cardiorespiratory fitness and cognitive benefits.
Energy and Endurance

• Energy throughout the day is a form of endurance 
  • Avoid lulls and fatigue, maintain focus and enjoyment in daily activities
• Muscular endurance: repeat small efforts in a muscle group without fatigue 
  • Example: walking up flights of stairs without quads burning
• Maximum anaerobic capacity: perform a large amount of work for 20–80 seconds 
  • Example: paddling hard for a minute while surfing or biking up a steep hill
• Maximum aerobic capacity: repeat high-​​effort activities for 5–15 minutes 
  • Example: running a mile or completing longer distance intervals
• Sustained position: maintain posture and position for extended periods 
  • Example: sitting with perfect posture at work, standing in line without collapsing

Improving Endurance

• Incorporate short bursts of maximal exertion throughout the day 
  • Example: running up stairs, jumping jacks, or burpees for 20 seconds every 4 hours
  • Adjust frequency and duration to fit personal schedule and abilities
• Use single-​​ingredient supplements to support hormone health, sleep optimization, and focus 
  • Momentous offers high-​​quality, single-​​ingredient supplements that ship internationally
• Monitor blood glucose levels with a continuous glucose monitor, like Levels 
  • Learn how different foods, exercise, and sleep impact blood glucose levels
  • Optimize schedule and habits based on personal data

• Maintain proper electrolyte balance with sodium, magnesium, and potassium

  • Element provides a science-​​backed ratio of electrolytes to optimize mental and physical performance
  • Important for hydration and cellular functioning, especially for those with clean diets and active lifestyles
    Improving Endurance and Fatigue Management

• Endurance factors:

  • Sustained high-​​intensity exercise
  • Repeated high-​​intensity exercise
  • Long-​​duration low-​​intensity exercise
  • Maximum distance
• Goal: Perform these activities and feel good afterwards
• Endurance reflects fatigue management and energy production 
  • Different functional capacities have different points of failure
  • Optimize performance by understanding how to make energy and handle fatigue

Energy Production and Fat Loss

• Body has different fuel sources: 
  • Glycogen (stored in muscle and liver)
  • Body fat (stored in white adipose tissue)
  • Protein
  • Phosphocreatine system
• Body fat stores are tapped into when other fuel sources are depleted or when energy systems signal that body fat is the optimal fuel source
• Fat loss occurs through respiration 
  • Breathing in oxygen (O2) and exhaling carbon dioxide (CO2)
  • Carbon molecule difference between O2 and CO2
  • Carbohydrates and fats are chains of carbon
  • Metabolism breaks carbon bonds to produce energy and create ATP
  • Carbon must be removed from the body through respiration

Carbon Cycle of Life

• Plants breathe in CO2 and exhale O2, while humans do the opposite
• Plants use photosynthesis to form bonds between carbon atoms, using energy from the sun
• Plants produce starches and fruits by storing carbon and converting it into different forms of carbohydrates (sucrose, glucose, fructose)

• The human body also stores and converts carbohydrates in a similar manner
  Understanding Glucose, Starch, and Glycogen

• Glucose: six carbon chain found in blood

• Starch: glucose packed away in potatoes and other tubers
• Glycogen: glucose packed away in muscles, such as the quadricep
• Fructose: found in fruits

Carbon Intake and Exhaling Carbon

• Humans need to ingest carbon to survive, as they cannot perform photosynthesis
• Carbon sources include starch, fruit, and animal products
• Carbon is stored in the body as carbohydrates (liver, blood, muscles), fat (adipose tissue, intramuscular triglycerides), and protein (used for structure)
• To lose weight, one must either ingest less carbon or expel more carbon

Breathing and Fat Loss

• Increasing the rate of exhalation can lead to fat loss
• Hyperventilation training increases adrenaline levels and can lead to fat loss, but is not sustainable due to side effects
• Steady-​​state exercise, weight lifting, and interval training all increase respiration rate and can lead to fat loss
• The type of exercise or diet does not matter as much as the total carbon intake and output

Lung Capacity and Fat Loss

• Increasing lung capacity may help with fat loss by offloading more CO2 carbons per exhale
• However, net carbon output over the course of the day must also be considered

• Increasing the demand for energy through exercise is necessary to achieve a negative carbon balance and promote fat loss
  Energy Production and Metabolism

• Cardiac output (Q) = heart rate x stroke volume

  • Adjusts to meet energy needs
  • Endurance training can lower resting heart rate and increase stroke volume, but cardiac output remains the same
• Resting heart rate as a metric of fitness 
  • Lower resting heart rate indicates better fitness
  • Sub-​​60 beats per minute is a good target for most people
• Maximum heart rate not a good proxy for fitness 
  • Does not increase with fitness
  • Stroke volume limited by filling capacity of the heart

Fasted Training and Fat Loss

• Training fasted does not necessarily enhance fat loss 
  • Misunderstanding of metabolism
• Respiratory exchange ratio (RER) or respiratory quotient (RQ)
  • Ratio of O2 to CO2
  • Increases with exercise intensity
  • At rest: 0.6–0.7
  • Walking: 0.8
  • VO2 max: 1.1
• Excess post-​​exercise oxygen consumption (EPOC)
  • Continued ventilation after exercise to pay back “oxygen debt”
  • Higher intensity exercise requires more ventilation to deal with waste accumulation in tissues

Energy Utilization and Exercise Modes

• Different modes of exercise trigger specific adaptations 
  • Walking: low intensity, matches energy needs with waste offload
  • Sprinting: high intensity, requires more ventilation to deal with waste
  • Moderate jog: intermediate intensity, different breathing pattern

• Understanding the relationship between energy production, utilization, and exercise modes can help optimize training and fitness goals
  Excess Post-​​Exercise Oxygen Debt and Fuel Sources

• Excess post-​​exercise oxygen debt: repaying oxygen debt after exercise

• RQ (Respiratory Quotient) increases with exercise intensity 
  • RQ of 1.0 indicates high intensity exercise
• Misconception: exercising in a “fat-​​burning zone” leads to more fat loss 
  • Lower intensity exercise burns a higher percentage of fat, but total fuel expenditure is low
  • Higher intensity exercise burns a higher percentage of carbohydrates, but total fuel expenditure is higher

Understanding Fat Loss vs. Fat Burning

• Burning fat does not equal losing fat from the body
• Burning body fat stores vs. burning dietary fat
• Reducing body carbohydrate stores (muscle glycogen, liver glycogen) occurs during high-​​intensity exercise

Optimizing Exercise for Fat Loss

• Speed, power, and skill development have minimal benefit for fat loss
• Strength training has some benefit, but total energy expenditure is low
• Hypertrophy and muscular endurance training (6–30 repetitions) can help deplete muscle glycogen
• High-​​intensity interval training can further deplete muscle glycogen and potentially liver glycogen

Energy Production and Regulation

• Energy production comes from local exercising muscle (phosphocreatine and carbohydrate stores)
• Body regulates blood pH, blood glucose, blood pressure, and electrolyte concentrations
• Liver glycogen is the last resort for energy production

Potential Fat Loss Protocol

1. One hour of hypertrophy or muscular endurance training (6–30 repetitions)
2. High-​​intensity interval training (30–60 seconds with ample recovery)
3. Steady-​​state cardiovascular exercise (optional)

Note: Total energy expenditure is the key factor for fat loss, not the specific fuel source (fat or carbohydrates).
Glucose as Primary Fuel Source for the Brain

• Glucose is the primary fuel source for the brain
• Blood glucose concentrations rise during exercise as an anticipatory state
• Liver kicks in to break down glycogen to maintain blood glucose levels

Glycogen Depletion and Fatigue

• Fatigue signals occur when muscle glycogen levels are lower than 75%
• Most people quit around 50% depletion
• Liver depletion leads to complete shutdown (e.g., marathon runners “bonking”)

Liver Depletion and Neural Signals

• Liver depletion likely sends a neural signal to the brain to stop activity
• Brain prioritizes self-​​preservation over pushing through fatigue
• Override switches can be activated to push past fatigue, but can lead to breaking down quickly

Converting Fat to Muscle and Muscle to Fat

• Fat cannot be turned into muscle, and muscle cannot be turned into fat
• These are separate structures with different functions

Losing Stored Fat and Glycogen Replenishment

• Burning muscle glycogen while in a hypocaloric state (below total caloric need) leads to fat loss
• Calories in and calories out are complex and interconnected
• Carbohydrates and fat are complementary systems, not “either/​​or” systems
• Carbohydrates provide flexibility and quick energy, while fat provides unlimited capacity

Metabolic Flexibility

• Metabolic flexibility refers to using optimal fuel sources and types, not just maximizing fat burning
• The goal is to maximize the ability to use both carbohydrates and fat as fuel sources

• In a hypocaloric state, ingested carbohydrates are biased towards glycogen storage, while fat is utilized for activity and general physiology
  Metabolic Flexibility and Fat Loss

• Metabolic flexibility: the ability to switch between using carbohydrates and fats for energy

• No specific standard for metabolic flexibility 
  • Depends on individual goals and activities
• Some markers to consider for metabolic flexibility: 
  • Blood glucose levels 
    • Ideally around 85 mg/​​dL or lower
    • Every point increase above 85 increases the likelihood of developing type 2 diabetes by 6%
  • AST and ALT levels 
    • AST to ALT ratio around 0.8 or lower
    • Associated with blood glucose regulation
  • Performance tests
    • Standard workout with objective measures (time, heart rate, perceived exertion)

Understanding Metabolic Flexibility

• Metabolic flexibility is not always optimal for specific activities or sports 
  • Glycolytically dominated sports may benefit from a bias towards carbohydrate utilization
  • Endurance sports may benefit from a bias towards fat utilization
• Most people want to feel great throughout the day and be able to do various activities 
  • Metabolic flexibility can help with this

Assessing Metabolic Flexibility

• No single test can definitively determine metabolic flexibility 
  • Look for patterns in biomarkers, symptomology, and performance
• Some tests to consider: 
  • Blood glucose levels
  • AST and ALT levels
  • Performance tests (standard workout with objective measures)
• These tests should be considered informative and useful, but not diagnostic

Increasing Metabolic Flexibility

• No specific standard for increasing metabolic flexibility 
  • Depends on individual goals and activities
• Some general recommendations: 
  • Maintain a balanced diet with appropriate macronutrient ratios
  • Engage in regular exercise, including both aerobic and anaerobic activities
  • Monitor biomarkers and adjust lifestyle factors accordingly

Fasted Training and Fuel Utilization

Enhancing Fat and Carbohydrate Utilization

• Enhancing fat utilization: 
  • Train in a pre-​​fat ingested state
  • Ingesting fat prior to training can signal the body to preferentially target fat as fuel
  • Be aware that relying on fat as fuel may hinder top-​​end performance
• Enhancing carbohydrate utilization: 
  • Train at a higher intensity
  • Ingest carbohydrates before exercise to bias towards carbohydrate utilization
  • Ensure protein and fiber intake is stable and combined with carbohydrate intake to help stabilize blood glucose levels

Identifying and Addressing Fuel Utilization Issues

• Identifying poor fat utilization: 
  • Difficulty performing fasted training
  • Slow heart rate recovery after exercise
• Identifying poor carbohydrate utilization: 
  • Crashing after consuming carbs
  • Slow to start during exercise
• Addressing fuel utilization issues: 
  • Conduct extensive analyses (blood panel, urine, saliva, stool) to identify underlying causes
  • Ensure proper food combinations (protein, fiber, and carbs)
  • Train at appropriate intensities and with specific fuel sources to improve utilization

Fasted Training and Nutrition Options

• Fasted training is not required for fat loss or fat adaptation, but it can be a useful tool

  • Offers flexibility in training and nutrition options
  • Can be combined with various nutrition strategies (high carb, low carb, etc.) to achieve performance and physique goals
    Understanding Macronutrient Metabolism and Energy Production

• Body uses ingested macronutrients as fuel sources

  • Fat, carbohydrates, and glycogen are used for energy
• Energy production and waste management are key factors in endurance

Cellular Physiology and Energy Production

• Nucleus: holds DNA
• Mitochondria: involved in aerobic metabolism
• Cytoplasm: space between organelles, where anaerobic metabolism occurs

Anaerobic Metabolism

• Fastest way to produce energy
• Limited by storage capacity in cells
• Phosphocreatine stored in cytoplasm, used for quick energy
• Muscle glycogen also stored in cytoplasm, used for fast energy production

Aerobic Metabolism

• Occurs in mitochondria
• Produces more ATP than anaerobic metabolism
• Involves the TCA cycle (Krebs cycle)

Carbohydrate Metabolism

• Glucose: a six-​​carbon chain (C6H12O6)
• Glycolysis: splitting glucose into two three-​​carbon chains (pyruvate)
• Pyruvate can be converted to lactate, which can be used as fuel or transported to non-​​exercising muscles
• Acetyl CoA: two-​​carbon chain formed after pyruvate loses a carbon
• Krebs cycle: acetyl CoA enters the mitochondria and goes through a series of reactions, producing ATP and releasing carbon

Fat Metabolism

• Similar to carbohydrate metabolism, but involves breaking down fatty acids
• Slower process, but produces more ATP

Waste Management and Fatigue Buffering

• Anaerobic glycolysis produces waste products, such as hydrogen ions and inorganic phosphates
• Lactate helps manage acidity by binding to hydrogen ions
• Endurance is influenced by the ability to handle waste products and maintain energy production

Oxygen Availability and Energy Production

• Oxygen is required for aerobic metabolism and waste management
• Heart is an important site for oxygen availability and lactate processing
  Energy Systems and Fuel Sources in Exercise

Phosphocreatine System (0–20 seconds)

• First source of energy for muscle contraction
• Stored in the cytoplasm of muscle fibers
• 1 molecule of phosphocreatine gives 1 molecule of ATP
• Fast energy output, but limited in duration

Anaerobic Glycolysis (20 seconds — 2 minutes)

• Carbohydrate metabolism
• Initially uses glycogen stored in exercising muscle
• Can pull from blood glucose and liver glycogen if needed
• Glucose (6 carbon chain) is split into two 3‑carbon chains (pyruvate)
• Net gain of 3–4 ATP molecules
• Fast energy production, but limited in duration
• Training adaptation: increased glycogen storage in muscles

Aerobic Metabolism (2 minutes — marathon)

• Occurs in the mitochondria
• Pyruvate must enter the mitochondria to continue energy production
• Aerobic metabolism of carbohydrates, fats, and proteins
• Fuel source ratios change depending on exercise duration and intensity
• Longer duration, lower intensity exercise relies more on fat stores
• Ingested carbohydrates, fats, and proteins can also contribute to energy production

Short Duration Exercise (Sprinting, 1 minute or less)

• Primarily uses phosphocreatine and anaerobic glycolysis
• Limited contribution from ingested carbohydrates, fats, or proteins

Medium Duration Exercise (3–5 minutes)

• Transition from anaerobic glycolysis to aerobic metabolism
• Increased reliance on ingested carbohydrates, fats, and proteins
• Stored glycogen and blood glucose still contribute to energy production

Long Duration Exercise (20 minutes — marathon)

• Predominantly aerobic metabolism
• Increased reliance on fat stores and ingested fats for energy
• Carbohydrate stores and ingested carbohydrates still contribute to energy production
• Protein contributes minimally to energy production, but can increase with prolonged exercise and depleted carbohydrate stores

Understanding Energy Production and Utilization of Carbons

• Breaking down glucose for energy production 
  • Starts with a six-​​carbon glucose molecule
  • Split into two three-​​carbon molecules called pyruvate
  • Anaerobic glycolysis produces a small amount of energy
• Dealing with excess carbon 
  • When pyruvate is converted to a two-​​carbon molecule called acetyl-​​CoA, a free-​​floating carbon is produced
  • Oxygen is needed to combine with the free-​​floating carbon to create CO2, which is exhaled
  • This process occurs in the mitochondria
• Limitations of anaerobic glycolysis 
  • High rate of waste production, leading to a buildup of lactate
  • Lactate is not the cause of fatigue, but rather an acid buffer
  • Can be used as a fuel source for exercise and cognition
• Aerobic glycolysis
  • Occurs when pyruvate is transported into the mitochondria
  • Can last from 90 seconds up to several hours, depending on the individual and activity
  • Competitive marathon runners rely heavily on carbohydrates for energy
• Ingesting carbohydrates during exercise 
  • Many endurance athletes consume carbohydrates at specific intervals
  • Be cautious of ingesting too many fast carbohydrates before exercise, as it can cause a blood sugar crash
  • Practice your nutrition strategy during training to avoid surprises during a race or event
• Recap of energy production process 
  • Glucose is split into pyruvate through anaerobic glycolysis
  • Pyruvate is transported into the mitochondria and converted to acetyl-CoA
  • Acetyl-​​CoA goes through the Krebs cycle, producing ATP, water, and CO2
  • The end product of carbohydrate metabolism is ATP, water, and CO2

The Importance of Exercise for Cognition

• Exercise has been shown to improve memory retention and exam scores 
  • 20 minutes of exercise prior to taking an exam can lead to better performance
  • Lactate produced during exercise may contribute to these cognitive benefits
• Wendy Suzuki, a previous guest on the Huberman Lab podcast, is a pioneer in the field of exercise and cognition 
  • Conducts research on the effects of daily morning exercise on learning and memory

General Exercise and Nutrition Tips

• Don’t try new supplements, nootropics, or drastically change your routine before an important exam or event
• Keep your routine consistent to ensure optimal performance

• Practice your nutrition and exercise strategies during training to avoid surprises during a race or event
  Bookending and Carbon Gain in Exercise

• Circle of life: carbon gain and metabolism in living beings

• Endurance and fatigue resistance: waste management and energy production
• Aerobic exercise: bringing oxygen into the system for carbon management
• Limiting factors in endurance events: muscle glycogen, liver glycogen, acid buffering systems

Energy Sources: Carbohydrates, Fat, and Protein

• Protein: contributes 5–10% of energy output, only aerobic, not a significant performance enhancer
• Fat: majority comes from systemic sources, intramuscular triglycerides provide a small amount
• Carbohydrates: faster energy source due to direct availability in muscles

Fat as a Fuel Source

• Fat metabolism: lipolysis, glycerol backbone, fatty acid chains, beta oxidation
• Final endpoint of fat metabolism: water, ATP, and CO2 (same as carbohydrate metabolism)
• Exercise for fat loss: personal preference, combination of challenging and enjoyable activities

Exercise and Hunger

• Relationship between exercise intensity and hunger stimulus: not well understood
• Individual experiences vary: some people feel hungry after exercise, others do not

• Factors to consider: personal preferences, appetite stimulating or inhibiting effects of exercise
  Caloric Expenditure and Exercise

• Total caloric expenditure not generally reduced with high intensity or steady state training

• Non-​​exercise activity thermogenesis (NEAT) increases with exercise
• Creating a caloric deficit through exercise helps with fat loss

Fuel Sources for Exercise

• Phosphocreatine: fast energy source, burns out quickly (like a match)
• Carbohydrate: moderate energy source, lasts longer than phosphocreatine (like burning newspaper)
• Fat: slow, long-​​lasting energy source (like burning wood)
• Protein: not an ideal energy source, body prefers not to use it (like trying to burn metal)

Low Carbohydrate Diets and Exercise

• Low carbohydrate diets can be effective for weight management and energy stabilization
• Not ideal for high-​​intensity or anaerobic exercise, as it downregulates enzymes responsible for using carbohydrates as a fuel source
• Works well for people who do limited exercise or low-​​intensity, long-​​duration activities

Nine Adaptations of Exercise

1. Skill and technique
2. Speed
3. Power (speed x force)
4. Strength
5. Hypertrophy
6. Muscular endurance
7. Anaerobic capacity
8. Maximal aerobic output
9. Long-​​duration exercise

Muscular Endurance

• Local muscle adaptation, not cardiovascular or systemic
• Involves activities with 5–50 repetitions (e.g., push-​​ups, sit-​​ups, pull-​​ups, planks, wall sits)

• Important for maintaining posture and performing repetitive tasks
  Metabolism and Muscular Endurance

• Limiting factors in performing 50 pushups in a row:

  • Not running out of fat or glycogen
  • Acid buildup and waste clearance in muscle tissue
• Large muscle groups (e.g., quads, glutes) produce more waste and pain than small muscle groups (e.g., triceps) 
  • Vomiting after intense exercise due to waste buildup in the system
• Muscular endurance requires managing acid buildup and waste clearance 
  • Plenty of fuel available
  • Capillarization (increase in capillaries) helps disperse waste products
  • Slight increase in mitochondria, but not the main focus due to short time frame

Strategies to Increase Acid Buffering Ability and Capillarization

• Train at the ability close to failure to increase blood flow and capillarization 
  • Specificity is key
• Repeatedly performing movements (e.g., wall sit, pushups, dips) provides stimulus for more capillaries to be built 
  • Increased capillaries help with oxygen delivery and waste removal
• Exact signal for capillary growth is not yet known 
  • Possibly a combination of acidity, carbon dioxide, and nitric oxide

Training Protocol for Muscular Endurance

• Exercise choice: high precision, targeting specific muscle groups and movement patterns 
  • To improve a specific exercise, perform that exercise regularly
• Order: perform exercises targeting different muscle groups to avoid excessive fatigue
• Volume: high repetitions, close to failure
• Frequency: depends on individual goals and recovery ability 
  • Can be multiple times per week for specific muscle groups
• Example training session: 
  • Pushups to failure
  • Wall sits to failure
  • Dips to failure
  • Rest and repeat for desired number of sets