Sports & Exercise Physiology Flashcards

Which energy system is primarily used during a 100-meter sprint?

Answer: ATP-PC system

The ATP-PC (Adenosine Triphosphate-Phosphocreatine) system is the primary energy system used during very short, high-intensity activities like a 100-meter sprint. This system provides immediate energy without oxygen, but its stores are limited, lasting only about 6-10 seconds.

What is VO2 max a measure of?

Answer: Maximum oxygen uptake

VO2 max, or maximal oxygen uptake, is a measure of the maximum amount of oxygen an individual can utilize during intense or maximal exercise. It is a widely accepted indicator of cardiorespiratory fitness and aerobic endurance capacity, reflecting the body's ability to deliver and use oxygen for energy production.

Which muscle fiber type is most resistant to fatigue?

Answer: Type I

Type I muscle fibers, also known as slow-twitch fibers, are highly resistant to fatigue. They are rich in mitochondria and myoglobin, making them efficient at using oxygen for sustained, low-intensity activities like long-distance running. In contrast, Type II (fast-twitch) fibers are powerful but fatigue quickly.

What does the term 'hypertrophy' refer to in exercise science?

Answer: Increase in muscle size

Hypertrophy refers to the increase in the size of muscle cells, leading to an overall increase in muscle mass. This physiological adaptation occurs in response to resistance training, where muscle fibers are stimulated to grow larger and stronger. It's a key goal for individuals aiming to build strength and improve body composition.

Which organ plays a major role in regulating body temperature during exercise?

Answer: Skin

The skin plays a critical role in regulating body temperature during exercise, primarily through the process of sweating. As the body heats up, sweat glands release moisture onto the skin's surface, which then evaporates and cools the body. Additionally, blood vessels in the skin dilate to allow more blood flow to the surface, facilitating heat dissipation.

What is the typical response of the heart rate to increasing exercise intensity?

Answer: Increases

As exercise intensity increases, the body's demand for oxygen and nutrients by working muscles also rises significantly. The heart responds by increasing its rate of contractions (heart rate) and the volume of blood pumped with each beat (stroke volume). This ensures that oxygenated blood is delivered more rapidly and efficiently to meet the elevated metabolic needs of the body.

Which hormone is released in response to physical stress and increases glucose availability?

Answer: Cortisol

Cortisol is a hormone released by the adrenal glands in response to physical and psychological stress, including intense exercise. Its primary function in this context is to increase the availability of glucose in the bloodstream. It achieves this by promoting gluconeogenesis (glucose production from non-carbohydrate sources) and glycogenolysis (breakdown of glycogen), providing essential fuel for the body's energy demands.

What role do mitochondria play in muscle cells during aerobic exercise?

Answer: Produce ATP

Mitochondria are often referred to as the 'powerhouses' of the cell because they are the primary sites for producing adenosine triphosphate (ATP), the main energy currency of the cell. During aerobic exercise, muscle cells rely heavily on mitochondria to efficiently generate large amounts of ATP by using oxygen to break down carbohydrates and fats, fueling sustained muscle contractions.

Which of the following is a chronic adaptation to regular aerobic exercise?

Answer: Increased capillary density

Increased capillary density is a significant chronic adaptation to regular aerobic exercise. This means the body develops more tiny blood vessels surrounding muscle fibers, which improves the delivery of oxygen and nutrients to the working muscles. Enhanced capillary networks also facilitate the more efficient removal of metabolic waste products, thereby improving endurance capacity and overall cardiovascular fitness.