Anaerobic Training Programs Overview

Adaptations to Anaerobic Training Programs

• Acute responses describe how body systems adapt to meet exercise demands.
• Chronic adaptations are positive changes in structure and function of systems following repeated exercise stress, leading to body changes in anatomy and physiology.
• Anaerobic training utilizes anaerobic energy systems (ATP-PC and Glycolytic).

Anaerobic Training

• This type of training does not depend on oxygen.
• Types include resistance training, plyometrics, sprint training, agility training, and high-intensity intervals.
• These activities stress the anaerobic energy systems and use high-intensity intermittent exercise bouts.

Performance Improvements from Anaerobic Exercise

• Muscular Strength: Increases in strength average around 40% in untrained individuals, decreasing to 2% in elite athletes, over various training periods (4 weeks to 2 years). Training shifts muscle fiber types (IIx to IIa), increasing fatigue resistance at similar force levels.
• Power: Optimal load for maximizing peak power output in jump squats is body weight (0% 1RM). Athletes with training have higher loads for optimal power in squat and power clean (30%-60% and 80% of 1RM respectively). The load for maximum upper body power (bench press) is between 46%-62% of 1RM.
• Local Muscular Endurance: Anaerobic athletes show enhanced endurance and oxidative / buffering capacity. Muscle adaptations show fiber type transition (IIx to IIb), increased mitochondria and capillaries, improved fatigue resistance, and enhanced metabolic enzyme activity.

Body Composition

• Resistance training increases fat-free mass and reduces body fat (up to 9%).
• Outcomes of resistance training include increases in lean tissue mass, metabolic rate, and energy expenditure during exercise.

Flexibility

• Anaerobic training can positively impact flexibility, with a combination of resistance training and stretching showing the best results for increasing flexibility with increasing muscle mass.

Aerobic Capacity

• In untrained people, heavy resistance training may increase VO2max from 5% to 8%, but in trained individuals, it does not significantly affect aerobic capacity.
• Circuits with short rest periods (30 seconds or less) are shown to improve VO2max.

Motor Performance

• Resistance training has been shown to improve running economy, vertical jump, speed, serve velocity (tennis), throwing speed, and kicking performance.

How Does Training Improve Performance?

• Application of stress on the body leads to adaptation.
• Adaptation is a change in structure or function resulting in an improved ability to respond to the stressor and maintain homeostasis.

Performance Adaptations from Resistance Training

• Variable:
• Muscular strength, muscular endurance, aerobic power, anaerobic power, rate of force production, vertical jump, sprint speed, fiber cross-sectional area, capillary density, mitochondrial density, myofibrillar density, myofibrillar volume, cytoplasmic density, and myosin heavy chain protein.
• Enzyme activity: Increases in creatine phosphokinase, myokinase, phosphofructokinase, lactate dehydrogenase, and sodium-potassium ATPase.
• Metabolic energy stores: Increases in stored ATP, creatine phosphate, glycogen, and triglycerides.
• Connective tissue: Possible increases in ligament strength, tendon strength, collagen content, and bone density.
• Body Composition: Decreases in body fat and increase in fat-free mass.

Measuring Neuromuscular Activity

• Electromyography (EMG) measures the electrical activity in skeletal muscles.
• Different types of EMG include surface EMG and intramuscular EMG.
• EMG can measure the amplitude of electrical activity and muscle activation (in percentage of maximum voluntary contraction).

Neuromuscular Responses

• Motor unit recruitment follows Henneman's size principle.
• Rate coding, excitation-contraction coupling, proprioception (GTO and muscle spindles), and the stretch-shortening cycle are involved.

Neural Adaptations to Anaerobic Training

• Chronic anaerobic training increases neural drive.
• There is increased recruitment of agonist motor units (71% higher for untrained individuals).
• Increased firing frequency allows summation of force production.
• There is increased synchronous recruitment, essential for force production timing (RFD = Rate of Force Development)
• Inhibitory mechanisms are reduced.

Motor Unit Recruitment

• There is better recruitment at very high threshold motor units.
• Once recruited, high threshold units require lower activation for the same force requirement.
• Post activation potentiation (PAP) is a key mechanism.

Neuromuscular Junction

• Increased end-plate surface area and acetylcholinergic receptors increase during training.
• Neuromuscular reflex potentiation is increased (19%-55%).
• Rate of force development (RFD) is improved, related to the neural adaptations.

Cross-Education Effect

• Improved neural adaptations benefit the non-exercised limb (contralateral).
• Neural adaptation results in on average an 8% increase in contralateral limb strength.
• Bilateral deficits in force are more pronounced in untrained individuals.
• Decreasing antagonist co-contraction potentially increases joint stability and reduces injury risk.

Muscular Adaptations (CSA)

• Increase in muscle size (hypertrophy)
• Net accretion of contractile and non-contractile proteins (e.g., titin).
• Larger number of myofibrils contribute to increased CSA.
• Increase in sarcoplasmic content.

Muscle Hypertrophy Mechanisms

• The growth of muscles due to resistance training stimulates new muscle protein synthesis.
• Mechanical tension facilitates anabolic pathways.
• Muscle experience tension through resistance training with rates elevated for up to 48 hours.
• Time for these effects are progressively shorter with advanced trainees.

Mechanisms of Muscle Hypertrophy

• Muscular fiber activation leads to endocrine responses, immune responses, and IGF-1 release.
• Growth hormone (GH), testosterone levels, and the immune response are released.
• These factors influence muscle protein synthesis and result in hypertrophy.
• Satellite cell differentiation and production contributes to increased myonuclei and myofiber CSA through microtrauma and myofibrillar and sarcoplasmic growth.
• The result, in part, is reduced muscle damage and inflammation.

Muscular Adaptations (EIMD and Hypertrophy)

• Training stress occurs via different mechanisms: muscle damage, hypertrophy-oriented, and repair-oriented.
• Muscle damage or repair-oriented responses impact protein synthesis.
• Hypertrophy-oriented responses involve muscle fiber size increase.

Muscular Adaptations (Fiber Type Transitions)

• Muscle fibers are categorized along an oxidative continuum (Ic to IIx).
• Training can shift fibers along this continuum, primarily due to changes in ATPase form.
• Early training stages cause transitioning to more oxidative fibers.
• It is less likely that type I to type II fibers will rapidly transform but possible.

Muscular Adaptations (Structural and Architectural Changes)

• Increased pennation angle increases force production capacity.
• Increased fascicle length improves contraction velocity.

Muscular Adaptations (Specific Adaptations)

• Increased sarcolemma and T-tubule densities affect calcium release / uptake.
• Reduced mitochondrial and capillary density may occur.
• Increased buffering capacity tolerates H+ accumulation.
• Increased substrate storage improves ATP, PC, and glycogen stores.

Connective Tissue Adaptations (Bone)

• Mechanical loading stimulates bone growth and osteoblast activity to secrete minerals to create a harder exterior surface, increasing bone density.
• Minimal strain results in minimal essential strain stimulus needed for new bone formation.
• Larger diameter distributes force to reduce stress related to bone and injury.

Connective Tissue Adaptations (Tendons, Ligaments, and Fascia)

• Collagen fibers form connective tissue and strength comes from cross-linking adjacent molecules; bundles arrange to connect bone to bone.
• Tendons connect muscles to bone, ligaments connect bone to bone, and fascia are connective tissue sheets.
• Tendons, ligaments, and fascia contain fewer active cells, resulting in lower blood supply and slower injury recovery compared to other tissues.
• These structures have small, elastic fibers which allows for slight stretch during movement.

Connective Tissue Adaptations (Cartilage)

• Dense connective tissue, including hyaline cartilage, provides substantial force-absorbing capacity.
• Hyaline cartilage lines joints, and fibrous cartilage is present in intervertebral discs and tendon junctions.
• Articular cartilage's main function include lubricating and absorbing joint forces related to lubrication and support.
• Cartilage lacks a good blood supply and relies on synovial fluid for nutrient delivery.

How Athletes Stimulate Connective Tissue Adaptations

• Long-term adaptation in tendons, ligaments, and fascia are facilitated by progressive high-intensity resistance training which uses external resistance.
• High intensity loads are necessary for significant changes.
• Full range of motion exercise is preferred, using multi-joint exercises as much as possible
• Moderate intensity training is adequate for increasing cartilage thickness while avoiding degenerative joint disease from too high or abruptly applied loads.
• Walking and proper range of motion through the joints improves synovial joint fluid.

Endocrine Responses

• Acute responses include elevated testosterone, GH, and cortisol post-resistance training.
• Magnitude is related to the amount of muscle activated, intensity, and rest periods.
• IGF-1 release is stimulated by mechanical loading.
• Catecholamines are released (e.g. norepinephrine and epinephrine) to regulate force and contraction rate, to increase energy availability, and/or influence other hormones in response to exercise demand.

Endocrine Adaptations (Chronic)

• Chronic changes in resting hormone levels are unlikely to be a significant factor following resistance training.
• Resting hormone levels are better indicators of current training stress and may reflect a recent change in training.
• Agonistic androgen receptor content is upregulated within 48 to 72 hours post-training.
• Chronic elevation of anabolic hormones can be counterproductive in the long term due to down-regulation.

Cardiorespiratory Responses

• Acute cardiovascular responses include increased heart rate, stroke volume, blood pressure, and oxygen uptake.
• Concurrent blood pressure elevation may not result in chronic high blood pressure.
• Blood flow to working muscles decreases during exercise contraction, but this lack of blood flow creates an anabolic stimulus, which is further enhanced by reactive hyperemia.

Cardiorespiratory Adaptations (Chronic)

• Resting heart rate may show no change or slight decrease (4–13%).
• Blood pressure may show a slight decrease (2–4%).
• Cholesterol is usually unchanged, with a possible slight improvement (LDL ↓/HDL↑).
• Left ventricular wall hypertrophy is possible.
• The cardiovascular response will be reduced at the same workload output after training.

Ventilatory Responses and Adaptations

• Ventilatory rate is generally not a factor in limiting anaerobic performance.
• Minimal improvements in ventilatory parameters are observed during maximal anaerobic exercise.
• Increased tidal volume and breathing frequency are noted with maximal exercise.

Concurrent Training

• Concurrent training (aerobic and anaerobic) may negatively affect anaerobic performance.
• Aerobic training may have a more negative effect on power and speed training, but not necessarily on strength training.
• The negative effects depend largely on volume, frequency, and intensity.
• The order (sequence), and duration (6 hours apart is recommended) or these training types can influence the effect on both anaerobic and aerobic performance and potentially contribute to the risk of overtraining.

Overtraining

• Overtraining is an accumulation of training stress that results in decrements in performance and maladaptations.
• Overreaching describes a short-term decrement in performance, as a result of excessive overload.
• Non-functional overreaching (NFOR) is a dysfunction in training, often with temporary symptoms after a period of training stress.
• Functional overreaching (FOR) is a consequence of training stress causing a functional decrement followed by recovery and then increased training load and functional adaptations.
• Overtraining syndromes (OTS) are the most prolonged form of overtraining, and can last for months or years, with chronic symptoms and maladaptations.
• Chronic overtraining has physiological symptoms, such as reduced hormonal balance (increase in estrogen and cortisol and decrease in testosterone), or emotional and sleeping problems.