Fechar
During exercise, many physiological processes are repeated in cycles which may be altered in frequency and/or magnitude. These are continually modified by the brain, and to some extent peripheral CO2/pH receptors, and some functions have anatomical reserves if necessary. Name three of these physiological processes.
Elite marathon runners run at what percentage of their VO2-max compared with average marathon runners? What enables them to do this?
True or false: lactate seems to be generated from glycogen in inactive muscle fibres?
Which organelles do well-trained endurance athletes possess greater concentrations of?
Before exercise even begins in a marathon, what are the five anticipatory processes that occur in the body?
As an anticipatory measure before a marathon begins, sympathetic autonomic nervous activity is increased, resulting in adrenaline being released. What physiological effects does this have?
Is the first mile of a marathon aerobic or anaerobic?
What are the two initial fuels for increased activity?
Respiratory and cardiovascular functions increase immediately upon the onset of exercise - but can they increase before?
What is the 'aim' of the respiratory feedforward mechanism before exercise begins? And the respiratory feedback mechanism once exercise has started?
Where in the brain are the cardiorespiratory centers?
Tidal volume and rate increase during exercise. Which predominately increases in low-moderate intensity exercise, and which predominately increases in high intensity exercise?
Which organs predominately control the body temperature at rest?
What is the leg muscle temperature at rest?
Around 10 minutes into a marathon (assuming the environment temperature has stayed the same), what are the temperature changes in the overall body temperature and the leg muscle temperature from rest?
What environmental factor might make it difficult to lose body heat during a marathon?
What are three ways in which the body tries to lose heat during a marathon?
What distance of a marathon is the 'long haul' or 'steady state'?
Why is there an increased in blood glucose in the first ~6 miles of a marathon?
Why does the blood glucose concentration tend to fall below the resting value in the last ~6 miles of a marathon?
What is the main fuel source during the latter half of a marathon?
Why is there a surge in epinephrine in the last ~4 miles of a marathon?
Mean arterial pressure increases during the marathon, both as a result of increased venomotor tone and compression of blood vessels by muscles. By how much does it increase from the resting value?
The baroreceptor reflex is not effective during exercise, as blood pressure is supposed to be increased in order maintain activity so seeing to lower it would be pointless. However, at what point during exercise might it become active again?
What role do metaboreceptors play in increasing blood pressure during high intensity exercise?
How does the orderly recruitment of respiratory muscles in order to maximise their efficiency and minimise overall work during exercise come about?
Despite gastrointestinal function being decreased during exercise (due to increased sympathetic activity as well as blood flow diverted to other organs) so that gastrointestinal motility is decreased, the physical activity of the body during exercise increases the movement of contents through the gastrointestinal tract. Why doesn't this result in diarrhoea?
Most marathons start in the morning, so by the latter stages of the race the ambient temperature has risen to around 30 degrees Celsius, for instance, reducing the ability to lose heat by convection. Assuming the humidity is low, heat loss via sweat is still effective. Why would this increased need to reduce body heat result in competition between organs for blood?
If blood distribution is considered to always be a competition between the skin, the muscles, the viscera, and the vital organs, where is the majority of the blood in the following conditions:
1) at rest in a neutral environment? 2) at rest in a warm environment? 3) during moderate exercise in a cool environment? 4) during moderate exercise in a hot environment?
During exercise, sweat production can reach up to what rate?
The fluid volume of the body is finite and fluid is lost during exercise, so conservation is critical to the maintenance of a healthy internal environment. What can the body do to conserve fluid during exercise?
Increased sympathetic activity and decreased glomerular filtration rate stimulate the release of what from the kidney juxtoglomerular cells? What effect does this have?
Is sweat hypo-osmotic or hyper-osmotic?
Why is the thirst response not sufficient for hydration in a marathon?
What is better for hydration during exercise: a sports drink or water?
What is 'hitting the wall'?
Fatigue is the 'early warning system' of the body that exertion is too high and energy reserves cannot support the activity much longer. Is the somatic or the autonomic nervous system in control in fatigue?
Which three broad factors does fatigue towards the end of the marathon result from?
List some of the intrinsic factors of fatigue within exercising muscle towards the end of a marathon.
How do H+ ions result in fatigue?
During normal exercise, muscle pH decreases quickly with increasing exercise intensity, and arterial pH decreases slowly until high intensity exercise. What is different in marathon/endurance exercise?
What is syncope? Why should you not stop exercising straight away after running a marathon?
What are the benefits to the body of fainting i.e. why does it resort to this drastic measure?
What is water intoxication? How does one avoid it?
What is post-exercise fever? Why isn't a raised temperature during exercise a fever?
What does DOMS stand for?
What is delayed onset muscle soreness?
