Topic 3 - Exercise Physiology and Bioenergetics

ATP(3), ADP(2), AMP(1)

  • Think of each of these systems like a factory

  • All three energy systems produce ATP

  • ATP is not energy, ATP is the storage form of energy. Energy is heat. This heat is measured through calories.

Metabolism

  • Metabolism: Total of all catabolic and anabolic reactions

    • Anabolism:

      • Constructs molecules - legos brought together

      • Requires energy

      • Known also as an endergonic process

      • Energy used/stored

    • Catabolism:

      • Breaks down molecules - Break legos apart

      • Units are oxidized to release energy or used in other anabolic reactions

Energy Systems

  • All systems work at the same time continously, but what is the primary one being used at certain times?

  • Highest to lowest concerning intensity:

    1. Phosphogen first

    2. Glycolytic second

    3. Oxidative third

  • The replenishment of ATP in human skeletal muscle is accomplished by three basic energy systems:

Phosphagen/ATP PCR system

  • Primary source of ATP for short-term, high-intensity activities (max force and output) but is active at the start of all types of exercise regardless of intensity.

    • EX: weightlifting, jumping, and the begining of sprinting

  • Creatine phosphate (CP) is stored in muscles (greater contractions in type II fibers) and is broken down to replenish ATP. And has larger motor units.

    • Creatine kinase increases rate of synthesis of ATP from ADP and CP

  • Energy yiels = 1 ATP per 1 CP

    • Lowest volume created but you get it quick (now)

    • Provides ATP the fastest

Glycolytic system

  • When decrease intensity to something that can be held for two minutes, the glycolitic system is teh primary system

  • Primary source of ATP for high-intesnity activity up to about 2min and takes over for the phosphagen system as duration of activity continues

  • Any intenisty where you can maintain it up to 2min and can not maintain that intensity longer then 2min

    • EX: racquetball or running 600-800meters

  • Glycolysis = breakdown of carbohydrates from blood glucose or muscle glycogen to rplensig ATP and yield pyruvate and H^+

    • Pyruvate enters either…

      • Fast glycolysis: if high inetnisty activity is converted to lactate

      • Slow glycolysis: if moderate intenisty activity it enters the mitochondria (is actually acrobic metabolism)

    • At the moment at which pyuvate apears is oxygen also present?

      • If oxyegn is present, that indicates a lower intensity.

      • If oxygen is not present it converts to lactate and it is fast glycolysis and higher intensity

    • Stimulated by ADP, AMP, P, ammonia, and a slight decrease in pH

    • Inhibited by: Markedly lower pH or increased levels of ATP, CP, citrate, and free fatty acids.

      • Free fatty acids cointains a lot of energy so you don’t need to use Glycolysis

    • Energy yield = 2ATP per glucose, 3ATP per glycogen

    • Blood Lactate

      • Hydrogen accumulation = low pH = more acidic. Lactic acid is converted rapidly into lactate = burning sensation. the burning sensation is just a warning to teh body to let it know it is running out of ATP

      • Lactate istaken to the liver where it is converted to glucose, and that glucose is either released into the bloodstream or repackaged into glycogen. Then we have more energy to use again

      • Gluconeogenesis: the creation of new sugar

        • Gluco = sugar

        • Neo = new

        • Genesis = the creation of

      • Lactate threshold (LT): the point at which the body can no longer use lactate from the bloodstream as quick as it builds up. It’s also known as the anaerobic threshold or aerobic to anaerobic transition point

        • Onset of blood lactate accumulation (OBLA): second point of inflection on the curve and is the point at which lactate builds up in the blood at a faster rate

      • Lactate Threshold

        • Untrained = 50-60% of VO2 max

        • Trained = 70-80% of VO2 max

        • Why is lactate threshold used instead of VO2 max? It is not about how much lactate is produced, it is about how much is accumulated (This person’s energy system is trained this way or not - not if someone is fit)

        • If we can push more lactate to teh right (greater threshold) then we can do more intensity before we hit lactate threshold

Oxidative System

  • Oxidative System is the recovery system

  • Primary source of ATP at rest, low-intensity long duration and aerobic activities

    • EX: walking on a treadmill, water aerobics, yoga class, etc.

  • Oxidation = uses primarily carbohydrates and/or fats as substrates

    • At rest, 70% of the ATP produced is derived from fats and 30% from carbohydrates

    • AT onset of activity, and as intensity increases, tehre is a shift from fats to carbohydrates

    • During high-intensity aerobic exercise, aklmost 100% of teh energy is derived from carbohydrates

    • Protein can be used during long-term starvation and ong steady-state bouts (>90min) of exercise

  • Carbohydrate oxidation = glucose/glycogen oxidation where pyruvate is transported into mitochondria and is converted to cetyl-CoA

  • Fat oxidation = triglycerides stored in fat cells are broken down and released as free fatty acids (FFAs) into the blood stream to reach miuscles and mitochondria

    • Beta oxidatiobn = FFAs broken down to form acetyl-CoA and H+.

      • H+ carried by NAD and FADH to the electron transport chain

  • Protien oxidation = protein, primarily branched-chain aminok acids, can be converted to various substrates to replenish ATP

    • Nitrogen, a waste of amino acids breakdown, eliminated through urea or ammonia

  • When pyvate neters teh mitochondria it is converted to Acetyl-CoA

    • Acetyl Co-A eneters Krebs cycle for further ATP production

  • When NADH or FADH2 eneters the mitochondria it then enetrs teh electron transport chain (ETC)

  • Electron Transport Chain (ETC)

    • Oxidative phosphorylation priduces ATP from ADP, NADH and FADH2 molecules

      • Concentration gradient or protons provides energy for ATP production

      • Oxygen final acceptor created water

      • 1 NADH = 3 ATP

      • 1 FADH2 - 2 ATP

  • Oxidative Energy Yield

    • Slow Glycolysis is anarobic and the ATP yield is 10 and when it goes through REB cycle it goes to 40 fatty acids which are really high in ATP

All three Eneregy Systems

  • All three energy systems are active at a given time… the extent to which each is used depends primarily on the intensity of the activity and secondarily on its duration

Effect of Event Duration on Primary Eneregy System Used

Duration of event

Intensity of event

Primary energy system (s)

0 to 6 s

Very intense

Phosphagen

6 to 30 s

Intense

Phosphagen and fast glycolysis

30 s to 2 min

Heavy

Fast glycolysis (This one is the best to train lactate threshold)

2 to 3 min

Moderate

Fast glycolysis and oxidative system

>3 min

Light

Oxidative system (This one is teh best to train VO2 max)

Using Interval Training to Train Specific Eneregy Systems

% of maximum power

Primary System stressed

Typical exercise time

Range of work-to-rest period ratios

90-100

Phosphagen

5-10 s

1:12 to 1:20 (for every second on, 12-20sec off)

75-90

Fast glycolysis

15-30 s

1:3 to 1:5

30-75

Fast glycolysis and oxidative

1-3min

1:3 to 1:4

20-30

Oxidative

>3min

1:1 to 1:3

  • Training the Phosphagen System

    • Deplete because of high-intensity exercise

      • Creatine phosphate decreases about 50-70% during first 5-30 seconds

      • ATP decreases no more than about 60%

    • Resynthesis

      • Complete resynthesis of ATP within 3-5 min

      • Complete resynthesis of creatine phosphate within 8 min

        • Can supplement to increase repletion

  • Training the Glycolytic System

    • Limited stores of glycogen: about 500g

      • Muscle = more important source for moderate- and high-intensity exercise

        vs.

      • Liver = more important during low-intensity exercise

    • Depletion is a limited factor to exercise and is directly related to fatigue. Carbohydrates are preferred fuel at intensities about 60% to 75% of VO2max

    • Resythesis is related to postexercise carbohydrate ingestion…

      • Most rapid in the first 5-6 hours but may take up to 24 hours for complete resynthesis

  • Training the Oxydative System

    • Oxygen Consumption: Measure of a person’s ability to take in and use oxygen

      • At the start of all exercise, we have an oxygen deficit when some energy supplied by anaerobic mechanism

        • Oxygen deficit: a temorary shortage of oxygen that occurs when the body needs nmore oxygen than it can breathe in

      • After exercise we have an oxygen debt or excess post oxygen consumption (EPOC) as the body is being restored to pre-exercise levels and uptake remains above resting levels

        • EPOC: the increase oxygen uptake your body needs after intesne exercise to restore itself to a resting state

    • Oxygen Uptake

      • Oxygen deficit is determined by amount of anarobic energy system involved (phosphogen and glycolgic system)

      • Steady state: you can hold an intenisty continuosly for multiple minutes or greater without significant heart rate variability

      • EPOC is determined by the amount of oxygen deficit

        • For a steady state actiovity, the anaerobic demand is minimal, tehrfore teh EPPC is minimal

          vs.

        • There is a high anaerobic demand, therefore the EPOC is large

      • VO2max: the highest intenisty where your oxydative system is primary

Exercise Physiology

  • Exercise Physiology: studes how the body repsonds to phyisical activity and adapts to exercise over time

Terminology

  • Response

    • Acute stress changes

      • Something has a rapid onset and a relatively short duration

      • Deal with a single bout of physical activity and/or exercises

        • Can occur during or immediatley after

  • Adaptation

    • Chronic stress chnages

      • Something that has slower onset and a relatively long duration

      • Deal with repeated training/a program and persists over time

Responses and Adaptations to Resistance Training

Factors Influencing Responses/adaptations

  1. Age

    • Over time our body loses its ability to produce force and generate movement rapidly

      • This can be reversed or manipulated by high-intensity resistance training

    • Age-related muscle and bone mass loss

    • Osteoporosis

      • Adipokines: are protiens secreated by fat cells.

        • There are two types:

          1. Antiflamatory

          2. Proinflamatory

        • Obese individuals have an adipokines imbalance. Specifically ther are too many axcess proinflamatory adipokines and not enought antiflamatory asipokines. This leads to a constant state of low grade inflamation. When this is the case, the bones start to break down

      • Females are at greater risk because there during menopause there is a decrease in estrogen production. And etrogenis a producer of testosterone, which is anabolic, a builder. When there is a drop in a builder, that can result in low bone mineral density.

      vs.

    • Sarcopenia

      • Myokines

        • When we exercise and muscle train, we release myokines and prevent muscle loss

        • Myokines are released by muscle tissue after a muscle contraction

        • When a person is seditary, their body is not producing as many myokines

        • Myokines contribute to maintaining muscle protein

      • Sarcopenia is age related muscle atrophy. The myokines, when released by muscle contracction, walk around and keep the muscle in place, it prevents muscle loss.

  2. Sex

    • Differences in strength gains, muscle mass, and acute hormone levels

      • Relative strength = similar

        • Accounts for body weight

      • Absolute strength = greater in males

        • Most prevalent in upper body

    • Fat mass and fat free mass percentages

      • Essential fat for males: 2-5

      • Essential fat for females: 10-13

    • Pre puberty

      • Boys - lower percentage of body fat than girls of similar age, ht, wt

    • During puberty

      • Boys - percent Fat mass decreases as fat free mass increases

      • Boys - Fat mass becomes more central (central adiposity)

      • Guirls - fat mass increases

    • Post puberty

      • Absolute Fat mass increases for both

  3. Genetics

    • Body “fatness” or even certain behaviors has been largely attributed to genetics

    • Individual genetic potential when gaining muscle mass, increasing strength, or losing fat is largely dictated by light differences in genetic code, or gene variants

  4. Specifity

    • The ability of the body to make adaptations that uniquely enhance performance in activity that are most like the exercise stressor

      • EX: distance running has little to no positive effect on bench press performance

    • Important notes:

      • Training mode, velocity of movement, and even typoes of contractions (muscle actions) are also highly specific.

Acute Responses to Resistance Training

  1. Neurological

    • Small muscles typically depend more meavily on firing rate (speed of motor unit recruitment) to control force output, while large muscles tend to depend more meavily on recruitment (increase in the total number or volume of motor units reqruiting)

    • Causes of fatigue

      • Motor unit recruitment increases to compensate for the loss in force production capability of the previously activated motor units

        • Each time we activate a motor unit, it becomes tired

      • Motor units that are firing a low rates at the satrt of teh set may have to fire at higher rates (rate coding).

        • If we fire it more times per minute it becomes more fatiggue

    • Motor unit recruitment based on the Size Principle

      • Lower-threshold motor units are typically activated during tasks that do not demand a high amount of force output

        • EX: maintenance of posture or walking

      • As demand for force output increases, low-threshold and high-trheshold motor units are simultaneously recruited to meet this demand

  2. Muscular

    • Accumulation of metabolites

      • EX: lactate, H+, Pi, ammonia

        • Hydrogen ions interfere with crossbridge formation. The more free Hydrogen ions, we have less force we are able to produce

    • Depletion of fuel substrates

      • EX: creatine phosphate and glycogen

    • What is the difference between lactate and lactic acid?

      • Lactate: colroless, odorless organic acid that is a byproduct of cellular metabolism

      • Lactic Acid: an organic acid produced in teh body during muscle metabolism

  3. Endocrine

    • Initial phases of training (3-4 weeks) show relatively equal synthesis and breakdown rates of msucle protein

    • Later phases of training show increased net protein balance = elevation of muscle protein synthesis rates

    • Increased blood concentrations of hormones

      • Hormones response is dependent on charcateristics of training sessions

        • Greater repsonse with higher volume and shorter rest as well as large muscle mass exercises

        • Maximum growth - maximum hypertrophy response - force the body to produce more - lots of sets with minimal rest

Acute Responses to One Bout of Resistance Exercise

Need to be able to explain why each of these Acute repsonses make sense

NEUROLOGICAL RESPONSE

Variable

Acute Response

EMG amplitude

Increase

Number of motor units recruited

Increase

MUSCULAR CHANGES

Variable

Acute Response

Hydrogen ion concentration

Increase

Inorganic phosphate concentration

Increase

Ammonia levels

Increase

ATP concentration

No change or slight decrease

CP concentration

Decrease

Glycogen concentration

Decrease

ENDOCRINE CHANGES

Variable

Acute Response

Epinephrine concentration

Increase

Cortisol concentration

Increase

Testosterone concentration

Increase

Growth hormone cocnentration

Increase

Chronic Adaptations to Resistance Training

  1. Neurological

    • In the first 1-2 months of a program, there is…

      • Improved form and technique

      • Increased:

        • Motor unit recruitment

        • Motor unit firing rate

        • Motor unit synchronication

      • Decreased:

        • Cocontraction/coactivation of muscles

      • Changes in motor neuron excitability

    • Advanced Training revers to days that are pure strength training, power training, or advance hypertrophy training

  2. Muscular

    • Increased Hypertrophy

      • Greater in Type II fibers compared to Type I

      • Increase in number of myofibrils (actin and mysosin) within a muscle fiber as well as cytoskeletal and structural proteins

    • Fiber subtype shift

      • Type IIx to Type IIa

  3. Endocrine/Metabolic

    • Minimal evidence of changes in resting hormone concentrations

    • Increase magnitude of acute response

    • Increase sensiticity of tissues to hormone release

    • Decrrease mitochondrial density yet no change to number of mitochondria (not a chnage in number of mitochindria, it menas density)

  4. Muscoskeletal

    • Bone mineral density affected by strain magnitude an strain rate

    • Potential decreased risk for osteoporosis

    • Tendons adapt to loads applied during training

      • Tendon gets stronger

      • Possible increased cross-sectional areas and changes in mechanical properties

    • Little data on ligamentous changes

      • Not enough evidence on ligaments - not enough blood flow

    • Training is effective treatment of osteoarthritis, but effects on cartilage are inconclusive

  5. Cardiorespiratory

    • Aerobic fitness adaptations are likelt dependent on age and pre-existing fitness levels

    • No negative effects on development of maximal oxygen consumption

    • Can arguent aerobic endurance eprformance by increasing strength and power

  6. Body Composition

    • Increased fat free mass and may decrease fat mass over time

Progressive Overload

  • Overtraining: condition in which an individual trains excessively, causing generalized fatigue and is marked by decreased performance

    • Types:

      • Overuse injury or muscle (joint and muscle specific)

      • Overtraining of the body (whole body is fatigued)

    • Results from increasing teh volume of teh program at too rapid a pace or maintaining too manyd ays of high intensity without varying load or taking a rest

    • Symptoms of overtraining from resistance exercise:

      • Plateau following by decrease of strength gains

      • Sleep disturbances

      • Decrease in lean bodyh mass (when not dieting)

      • Deacrease appetite

      • A cold taht just will not go away

      • Persistent flue-like symptoms

      • Loss of infterest in the training program

      • Mood changes

      • Excessive muscle sorness

  • Detraining: physioplogica; and performace adaptations tat occur when anindivdual ceases an ecxercise training program

    • Atrophy = loss of muscle mass

      • Sarcopenia: age related atrophy and can result in a loss of muscle fibers

      • Non-age related atrophy: due to a decrease in cross sectional area (the diameter) without the loss of muscle fibers

    • Changes to neurological function

      • Decreased recruitment, rate coding

      • Increase contraction

        • Why do we have a increase in co-contraction with detraining? Because the body is trying to provide for stability. The agonist decreases the amount of force it can produce and as a result we have an increase in co-contraction to make up for the loss of agonist force. The co-contraction provides an increase in stability.

Responses and Adaptations to Cardiovascular Fitness

  • The effects of aerobic exercise are regulated by the intenisty duration, and frequency of the activity

  • Intensity - primary determinant

  • To determine which energy system is primary, secondary, and tertiary - it depends on the intensity of the exercise - all three energy systems will eb present at some point, it is justg a factor of which one is more prominent and used?

Cardiovascular Fitness

  • Cardiovascular exercises: activities taht involve large muscles and challenge heart and lungs to work hearder

  • Aerobic Training

    • The measure for max aerobic capacity is VO2max

Factors Influencing Reposnses/Adaptations

  • Influence of Age on Changes

    • VO2max increases as children mature with highest values reached between

      • 12-15 years of age for females

      • 17-21 years of age for males

    • Values plateau and then decrease with aging

      • Decline can be negated with training

      • As we age, if we decrease our muscle mass, that results in a decrease in mitochondria

        • Why does this drop in mitochondria decrease breathing efficiency? Because when we take in a breath of air, the amount we can use as oxygenation depends on the amount of mitochondria we have. We use mitochondria to convert glucose and sugar to ATP with oxygen. And teh amount of O2 we can take is is dependant on the amount of mitochndria we have So if we have less mitochondria than that oxygen taht we breathe in to use to convert things to ATP. So O2 is wasted.

  • Influence on Biological Sex on Changes

    • Physiological changes similar for males and females

    • Absolute values differ due to body differences:

      • Females have less muscle mass, smaller heart and lungs, and smaller blood volume than males

  • Influence of Genetics on Changes

    • Individuals are born with a theoretical ceiling of human performance, a range that is dependent on training stimulus and motivation

      • Genetic factors account for about 20-30% of VO2max differences and abou 50% differences in max HR.

  • Influence of Specifity on Changes

    • The ability of the body to make adaptations that uniquely enhance performance in activities that are most likely teh exercise stressor.

      • EX: adaptations are specific to the type of exercise - running, swimming, cycling etc.

Cardiovascular: Acute Responses

NEED TO BE ABLE TO EXPLAIN EACH OF THESE:

  • Cardiac output (Q) increase

    • Heart rate (HR) increases

    • Stroke volume (SV) increases

  • Blood pressure (BP)

    • Systolic increases

    • Diastolic - no change or slight decrease

    • Mean arterial pressure increases

  • Excitation of the heart

    • Sympathetic increases

    • Parasympathetic decreases

  • Total peripheral resitance decreases: The rersistance in the circulatory system that is used to create blood pressure

  • Blood plasma volume decrease

    • Hematocrit increases - Hematocrit us the percent of red blood cells in the blood

Respiratory Acute Responses

  • Pulmonary minute ventilation increases

    • MV = tidal volume (ml) x breathing rate (bpm)

  • Respiratory exchange ratio (RER) increases

    • RER teh ratio of carbon dioxide (CO2) produced to oxygen (O2) consumed

    • Measures the proportion of fat, carbohydrate, and protien used during aerobic processes

    • Higher RER - mostly carbs

      • When you have an increase in the number of carbs that are burned, this increases teh amount of CO2 that is expelled, and that is the reason why the numbers change

    • Low RER - mostly fats

Metabolic/Endocrine: Acute Responses

  • Metabolism increases = increase CO2, increase lactate, decrease blood pH

  • Endocrine

    • Glucagen secretion increases

      • Glucagon stimulates glucose release

    • Insulin secretion decreases

    • Cortisol

      • Cortisol is repsonsable for uptake of repair components which results in synthesis of tissue post stress

      • Low-intensity exercise - Cortisol decreases

      • Moderate- to high-intensity exercise - Cortisol increases

        • Flight or fight responses is the Phosphagen system - quick energy

    • Growth hormone increases

    • Catecholamines increases

      • Epinephrine and norepinephrine

Chronic Responses to Cardiovascular Fitness

  • Cardiovascular Chronic Adaptations

    Cardio = oxidative system

    • VO2max increases - increase of number and size of mitochondria

    • At rest/submaximal intenisty

      • HR (within 2-20 weeks) decreases - there is a increae in perasympathetic tone which is in the body getting better and activating its calming response

      • Stroke Volume increases

      • < 10 mmHg changes in Blood Pressure

    • Long-term aerobic exercise

      • Cardiac hypertrophy increases

        • Left ventricle and myocardial wall thickness

      • Red blood cell volume increases

      • Capillary density increases

  • Respiartory Chronic Adaptations

    • Improved efficiency

      • Decreased energy cost per breath = more oxygen to muscles

        • With increase in mitochondria tehy don’t need to grasp for breath

        • When an oxidative energy system is untrained it is because tehy don’t have enough mitochondria in their muscles so they have to suck in a bunch of air

      • Less fatigue of diaphram/breathing muscles - they are more trained

    • Exercise Types:

      NEED TO KNOW THE DIFFERENCE BETWEEN SUBMAXIMAL AND MAX INTENSITY

      Why is it that submaximal intensity tidal volume frequency decreases but at maximal intensity it increases? Because less air is needed to do the same amount of work. In shape vs. out of shape - because of the number of mitochondria - not trained

      • Submaximal intensity: minute ventilation decrease - we have a drop because less air is needed to do the same aount of work

        • Tidal volume increases

          • Tidal Volume: the amount of air that moves in and out of the lungs per breath

        • Frequency decreases

      • Maximal intensity: MV increases

        • Tidal volume increases

        • Frequency increases

  • Metabolic/Endocrine: Chronic Adaptations

    • Increased energy efficiency: leads to greater capacity to perform at higher exercise intensities for prolonged periods

      • Increased:

        • Reliance on fat as energy

        • Lactate threshold

        • VO2max of 10-30%

      • Why is it that a increase in VO2 max will also lead to a increase in lactate threshold? Beacuse we are now able to run faster and longer relying more on the oxydative system instead of other systems which help us increase our lacate threshold

    • Endocrine

      • Enhanced insulin sensitivity

  • Musculoskeletal: Chronic Adaptations

    Why is it that chronic cardiorespiratory training results in an increase in muscle glycogen?

    • Relation to performance…

      • Capillary desnity increases

      • Mitochondrial density/size increases

      • Activity of oxidative enzymes increases

      • Intramuscular glycogen stores increases

        • If we imporve our oxidative capacity we are able to store more glycogen because we are not using as much

      • Myoglobin stores increases

    • Tendon/ligamants/capilage appears to remodel with mechanical stress

      • Most consistant evidence of hypertrophy is tendons.

      • Tissues will remodel according to mecanical stress.

    • Moderate to high bone-loading forces (jogging, jumping, etc.)

      • Maximize bone mass in early years

        • Hypothesis of Pech bone mass

      • Maintain bone mineral content through middle age

      • Combat bone mineral loss in older age

  • Other Chronic Adaptations

    • Body composition adaptations

      • Weight loss more likely to occur with moderate-intesnity cativity activity of >150 min per week

        • Minimal effect on fat free mass

Overtraining in Cardiovascular Fitness

  • Overreaching can occur with short-term training…

    • Recovery can occur within a few days or up to two weeks with appropriate intervention

    • Decrement in performance occurs followed by enhanced performance as compared to baseline

  • Overtraining occurs when adaptation capacity is exceeded without sufficient recovery…

    • More serious and results from untreated overreaching

    • Long-term impaiments in perfromance as well as other conditions

  • Signs of Cardiovascular Overtraining:

    • Unusual Muscle Soreness

    • Performance Plateaus

    • Chronic Fatige

    • Increased Resting Heart rate or Blood Pressure

    • Overuse Injuries

    • reproductive Issues

    • Unintentional Weight loss

    • Recurrent Illnesses

    • Decline in Motivation or Joy

    • Difficulty Sleeping

  • Overtraining Subtypes

    • Parasympathetic Dominant: Trouble firing up

      • caused by excessive volume and is found when aerobic endurance overtarining occurs

    • Sympathetic Dominant: Trouble calming down

      • Primarily teh result of high-intesnity overload and found with anerobic or resistance overtraining

Detraining of Cardiovascular Fitness

WHY DO EACH OF THESE THINGS HAPPEN?

  • Two weeks after training is stopped…

    • Muscular endurance decreases

    • VO2max and cardiac output decreases

    • Aerobic enxyme levels decreases

  • Four weeks after training is stopped…

    • Muscle’s respiratory ability decreases

    • Glycogen levels decreases

      • Because the body is not as efficent to the porycycle and tehrfore less able to store muscle glycogen

    • Lactate production increases

      • If you stop training the oxidative system that increases lactate threshold which means lactate will spike at a lower intensity