Strength and Conditioning Principles Study Notes

By the end of this lecture, students should be able to:
1. Appreciate the adaptations associated with strength training.
2. Measure and estimate maximum strength.
3. Prescribe appropriate exercise modes and dosages to elicit muscle growth.

Definition of Resistance Training: A method aimed at increasing strength, defined as the ability to produce more force.
Importance of Multi-system Adaptations: Resistance training leads to adaptations across various systems, which significantly impacts individual performance levels.
Performance Fluctuations: Recognizes intraday, interday, and microcycle fluctuations in performance based on introduced stressors.
Phases of Resistance Training Adaptation:
1. Alarm Phase: The initial phase when the stimulus of training is first recognized, often leading to a temporary decrease in performance due to fatigue.
2. Resistance Phase: The adaptation phase where the body returns to baseline performance or elevates beyond it.
3. Supercompensation Phase: Results in a new level of performance capacity as a response to the adaptations achieved in the resistance phase.
4. Overtraining Phase: When stressors exceed optimal levels leading to performance decline and potential overtraining syndrome.

ATP (Adenosine Triphosphate): The primary energy transfer molecule in the body.
- Breakdown of ATP releases energy necessary for muscle contractions.
Metabolic Systems: Both anaerobic and aerobic systems contribute to high-intensity exercises. For example, during a 3-second maximum cycling sprint, the distribution of energy sources is:
- 87% from phosphagen system
- 10% from glycolytic system
- 3% from oxidative metabolism.
References: Spencer et al. (2005), Haff & Triplett (2016).

Muscle Fiber Changes:
- Fiber cross-sectional area increases.
- Metabolic energy stores increase (e.g., ATP, creatine phosphate).
- Capillary density may not change.
- Mitochondrial density tends to decrease.
- Stored glycogen and triglycerides may increase.
- Myofibrillar volume increases, contributing to overall strength.
- Body Composition Changes: Increases in fat-free mass and decreases in % body fat.
Myofibrillar Density Changes: There are increases in myofibrillar density, while cytoplasmic density may change variably.

Hypertrophy Explanation: Increased muscle size occurs due to enhanced Ca²⁺ release and improved actin-myosin crossbridge formation.
Pennation Angles & Fascicle Length: Structural changes that positively influence muscle performance.

Shift in fiber type proportions based on genetic predisposition:
- Transition of fibers to different isoforms (e.g., Type IIx to Type IIa) through training.

Collagen Types:
- Type I collagen is found in bone, tendon, and ligaments, whereas Type II is found in cartilage.
Collagen Level and Enzyme Activity:
- Training increases enzyme activity which in turn improves collagen synthesis.
**Bone Adaptations: **
- Specific loading in bony regions enhances bone mineral density, e.g., running increases femur BMD, but not wrist.
- High-impact training like basketball or gymnastics effectively builds bone density.
- Progressive overload is important but should be monitored to prevent stress fractures.
Cartilage Adaptations:
- Movement initiates pressure changes that promote nutrient diffusion from synovial fluid, enhancing cartilage thickness through moderate intensity training.

Essential Parameters Before Exercise Prescription:
- Initial assessment of baseline strength based on:
- Training Status (Untrained to Well-Trained)
- Current Program and Training Age
- Weekly Training Frequency
- Training Stress Level
- Technique, Experience & Skill Levels.
Strength Categories:
- Untrained (≤ 2 Months): Low stress, minimal technique knowledge.
- Moderately Trained (2-6 Months): Medium training stress, basic technique knowledge.
- Well-Trained (≥ 1 Year): High training stress, high-level technique experience.

Definition: The maximum force exerted in one maximum contraction under proper technique.
Procedure for Estimating 1RM:
- Begin with warm-up 5 reps at 20% of estimated 1RM.
- Continue with progressively heavier reps:
- 3 reps @ 40% 1RM
- 3 reps @ 60% 1RM
- 1 rep @ 80% 1RM
- 1 reps @ 90% 1RM
- 1 rep @ 95% 1RM
- 1 rep @ 100% 1RM
- Allow for specific rest intervals between attempts.
- Note: Risk of estimation in untrained individuals; males tend to overestimate strength while females may underestimate, highlighting the need for careful consideration in certain populations.

Formula: $1RM = ext{kg} imes (1 - (x imes 0.02))$
- Example Calculation:
- Given a completed set of 10 repetitions at 100 kg:
  $1RM = 100 imes (1 - (10 imes 0.02)) = 125 ext{kg}$

Power Definition: Rate of energy transferred over time, measured in joules per second (J/s or W).
Assessment Methods:
- Lower limb power measured with broad jump (distance) and vertical jump (height).
- Upper limb power assessed with seated medicine ball chest pass (distance).

Methods to Assess Endurance:
- Isometric time to exhaustion using the plank.
- Repetitions to failure in exercises such as chin-ups or push-ups.

Strength and Power Goals:
- Strength: 1 reps at ≥ 85% 1RM.
- Hypertrophy: 6-12 reps at 75-85% 1RM.
- Muscle endurance: ≤ 67% 1RM for ≥ 12 reps.
Recommended Sets: 2-6 for strength and 3-5 for hypertrophy/endurance.

Key Components of Exercise:
- Segmentation and simplification of tasks to aid learning and performance.
- Proper feedback and appropriate dosage regarding frequency, session length, and task familiarity are critical.
- Tasks must be functional and align with overall movement patterns.