ACSM Exercise Science 3 — Questions and Answers
Question 1: What is the primary limiting factor for VO2max in highly trained endurance athletes?
- Skeletal muscle oxidative capacity
- Pulmonary diffusion
- Maximal cardiac output (Correct answer)
- Mitochondrial density
Correct answer: Maximal cardiac output
In elite endurance athletes, maximal cardiac output (heart rate × stroke volume) is the primary central limiting factor for VO2max.
Question 2: During resistance training, which principle states that muscles must be progressively loaded beyond habitual levels to stimulate adaptation?
- Specificity principle
- Reversibility principle
- Overload principle (Correct answer)
- Individuality principle
Correct answer: Overload principle
The overload principle states that training stimuli must exceed the current capacity of the body to drive physiological adaptations.
Question 3: At what blood lactate concentration is the lactate threshold (LT1) typically defined?
- 4 mmol/L
- 2 mmol/L (Correct answer)
- 6 mmol/L
- 1 mmol/L
Correct answer: 2 mmol/L
The first lactate threshold (LT1) is commonly identified at approximately 2 mmol/L, representing the onset of blood lactate accumulation above baseline.
Question 4: Which neuromuscular mechanism explains the initial strength gains in untrained individuals during the first weeks of resistance training?
- Muscle hypertrophy
- Increased satellite cell activation
- Neural adaptations and motor unit recruitment (Correct answer)
- Connective tissue remodeling
Correct answer: Neural adaptations and motor unit recruitment
Early strength gains in novice trainees are primarily attributed to neural adaptations including improved motor unit recruitment, firing rate, and synchronization.
Question 5: What is the approximate MET value for moderate-intensity walking at 3.5 mph on a level surface?
- 2.0 METs
- 3.5 METs (Correct answer)
- 5.0 METs
- 7.0 METs
Correct answer: 3.5 METs
Walking at 3.5 mph on a level surface is approximately 3.5 METs, classified as moderate-intensity activity (3–5.9 METs).
Question 6: Which substrate provides the fastest rate of ATP resynthesis during maximal intensity exercise?
- Muscle glycogen via glycolysis
- Plasma glucose
- Phosphocreatine (PCr) (Correct answer)
- Free fatty acids
Correct answer: Phosphocreatine (PCr)
Phosphocreatine provides the fastest rate of ATP resynthesis via creatine kinase, fueling the first 5–10 seconds of maximal exercise.
Question 7: What effect does eccentric muscle action have on delayed onset muscle soreness (DOMS) compared to concentric actions?
- Eccentric actions produce less DOMS
- Both produce equal DOMS
- Eccentric actions produce greater DOMS (Correct answer)
- Concentric actions produce greater DOMS
Correct answer: Eccentric actions produce greater DOMS
Eccentric contractions generate greater mechanical stress and microtrauma to muscle fibers, resulting in significantly more DOMS than concentric contractions.
ACSM Exercise Science 3
What is the primary limiting factor for VO2max in highly trained endurance athletes?