NHM ch 14

For example, a cross-country skier who skis continuously for two hours during a training exercise will need________________ of ATP. As a result, which of the following pathways would be best suited to this type of activity? a. Using creatine phosphate b. Glycolysis c. Oxidative phosphorylation

a sustained source c. Oxidative phosphorylation

To prepare for the cross-country meet, a skier decides to significantly increase the amount of carbohydrates in his diet (a technique also known as carbohydrate loading). Why might this be beneficial to the cross-country skier? Check all that apply. a. As long as oxygen is present, the glucose stored in the ingested carbohydrates can provide a steady stream of ATP, thus meeting the demands of prolonged periods of exercise. b. The liver can store copious amounts of ingested carbohydrates as glycogen, which can then be slowly broken down to release the glucose needed to fuel aerobic respiration. c. Carbohydrates are used to build actin filaments in the myofibrils, which increases muscle bulk and performance. d. Eating more carbohydrates leads to more glycogen stores in muscles, which then equates to larger energy stores for short, explosive bouts of energy use.

a. As long as oxygen is present, the glucose stored in the ingested carbohydrates can provide a steady stream of ATP, thus meeting the demands of prolonged periods of exercise. b. The liver can store copious amounts of ingested carbohydrates as glycogen, which can then be slowly broken down to release the glucose needed to fuel aerobic respiration.

Concerns about energy drinks include all of the following except: a. Consuming a 32-oz energy drink is not associated with more changes in the heart's electrical activity compared with other drinks containing the same amounts of caffeine. b. Vitamins, amino acids, and herbals are often in higher concentrations in energy drinks than naturally found in food or plants, and the effects when combined with caffeine, may be enhanced. c. Intakes greater than 100 mg of caffeine per day are associated with elevated blood pressure in adolescents. d. Interaction of caffeine with other ingredients in the energy drink may impact the function of your arteries by preventing them from dilating properly, especially during exercise. e. Service members who drank three or more energy drinks per day were more likely to only sleep 4 hours or less per night compared to those who drink two or fewer a day.

a. Consuming a 32-oz energy drink is not associated with more changes in the heart's electrical activity compared with other drinks containing the same amounts of caffeine.

1. Most energy drinks contain all of the following ingredients except: a. Guarana derived from a plant that contains caffeine. b. B vitamins. c. Fat. d. Taurine, an amino acid that can affect the levels of water and minerals in your blood. e. Large amounts of caffeine and sugar.

c. Fat.

2. Consuming energy drinks can be potentially dangerous for all of the following population groups except for: a. those under the age of 18. b. pregnant women. c. those who take Adderall for attention-deficit disorder. d. those who have a caffeine sensitivity. e. those who consume caffeine regularly and are substituting an energy drink for a cup of coffee.

e. those who consume caffeine regularly and are substituting an energy drink for a cup of coffee.

After the first 30 seconds or so of intense activity, muscle cells call upon the lactic acid system to produce more ATP. a. True b. False

false

Carnitine supplements both raise muscle carnitine concentrations and enhance exercise performance. a. True b. False

false

Energy drinks are an excellent choice for fluid replacement during athletic events. a. True b. False

false

Protein supplements are necessary to help build muscle. a. True b. False

false

Resistance training is critical for cardiorespiratory fitness. a. True b. False

false

The American College of Sports Medicine recommends that aerobic exercise be limited to no more than four days a week. a. True b. False

false

The increase in volume of the muscle fibers due to the enlargement of its components is referred to as ______________ .

hypertrophy

The subsections of a myofibril that perform muscle contraction are called _______________ .

sarcomeres

Identify the activities that would most likely improve an individual's cardiorespiratory fitness. Check all that apply. Swimming Running Front squatting Yoga

swimming and running

Even casual exercisers must attend to their fluid needs. a. True b. False

true

Flexibility allows the joints to move freely, reducing the risk of injury. a. True b. False

true

Immediately after the onset of a demand, before muscle ATP pools dwindle, a muscle enzyme begins to break down another high-energy compound that is stored in the muscle, creatine phosphate. a. True b. False

true

In hyperthermia, body heat builds up and triggers maximum sweating, but without sweat evaporation, little cooling takes place. a. True b. False

true

Only about 20 percent of adults in the United States meet physical activity guidelines. a. True b. False

true

Physically active young women, especially those who engage in endurance activities such as distance running, are prone to iron deficiency. a. True b. False

true

To meet the more prolonged demands of sustained activity, the muscles rely on the aerobic system to provide ATP for muscle contraction. a. True b. False

true

Walking at 3 to 4.5 miles an hour would be categorized as a moderate level of exercise. a. True b. False

true

When glycogen stores are depleted, a marathon runner will experience the phenomenon known as "hitting the wall." a. True b. False

true