KINES380 Final Exam

Warning Signs for Eating Disorders

Warning signs for anorexia nervosa (starvation): - rapid weight loss - mood swings - excessive exercise - avoiding food-related activities - wearing baggy clothes - preoccupation with food, calories, and weight Warning signs for bulimia (binging and purging): - noticeable weight loss - depressive moods - strict dieting followed by binge eating - excessive concern about weight - bathroom visits after meals - increasing criticism of one's body Female athletes might feel the pressure to reduce their weight in order for achieve a performance advantage or competitive edge.

FEV1/FVC

anything below 70% indicates the potential of a chronic obstructive pulmonary disease

Exercise Duration and Fuel Selection

- Prolonged, low intensity exercise - Shift from carb metabolism toward fat metabolism - Looks like cross over concept, except it is NOT

Female Athlete Triad

- cessation of menstrual cycle (amenorrhea - osteoporosis (bone mineral loss) - eating disorders (low available energy due to inadequate intake) The triad begins with a psychological/competitive stress, which then leads to eating disorders, which then can cause loss of bone density and amenorrhea. These problems are linked, and one problem can promote the other. For example, an eating disorder can cause a female to be deficient in calcium and vitamin D, which would directly affect her risk of bone mineral loss. Eating disorders are known to contribute to amenorrhea, which is associated with low estrogen levels. Both of these things can result in loss of bone mineral content.

Methods of Measuring Body Composition

- hydrostatic weighing: difficult for person, expensive - air displacement pleythsmography (BodPod): expensive, but accurate - dual energy x ray absorptiometry (DEXA) uses a three compartment model, most accurate but very expensive - bioelectrical impedance analysis because of its advantages (quick, cheap, portable) it might be something that people might believe is more accurate and appealing - skinfold: quick, cheap, portable, but not super accurate

Oxygen Supplementation

- meant to increase PO2 of the blood - has not been shown to significantly improve performance (did show evidence that it improves time to exhaustion) Prior to exercise - idea is to "store" O2 in blood, however you cannot really increase the amount of O2 that are bound to hemoglobin, you can only increase the amount of O2 dissolved in the plasma. - some evidence supports that breathing oxygen prior o exercise improves performance in short term events (within 2 minutes of event) - really not practical for athletes During Exercise - idea is to prevent muscle hypoxia by delivering additional O2 - no real increase in O2 delivery to muscle - CAN be beneficial to athletes who experience desaturation during exercise. After Exercise - idea is to speed up recovery time - early research showed that it was effective, however athletes knew they were breathing oxygen - later research shows no benefit

Retraining and VO2 Max

- muscle mitochondria react quickly to training (doubles within 5 weeks of training) - mitochondrial adaptations lost quickly with detraining (loss of 50% training gain within one week of detraining) - majority of adaptation is lost within 2 weeks - requires 3-4 weeks of retraining to regain mitochondrial adaptations -You will lose the effects of training faster than you can regain them

Creatine Supplementation

- supplementation increases muscle creatine levels - used for short term, explosive exercises - used to maintain force and power output - proves to be an effective aid in performance

Lactate Threshold

- the point during exercise that the rate of lactate production exceeds the rate of lactate clearance The point at which blood lactic acid rise systematically during incremental exercise o Appears at 50-60% of VO2 max o High work rates 65-80% in trained subjects Important variable with respect to predicting aerobic exercise performance Associated with o Anaerobic threshold o Onset of blood lactate accumulation (OBLA) Blood lactate levels real 4 mmol/L Importance for Runners: o Knowing the fastest pace you can keep during competition that will allow you to remain as fast as possible while remaining under the lactate threshold Importance for anaerobic o You want to be able to clear lactate quickly o If we can't clear it quickly, they need to be trained to work at higher intensities and perform well with high levels of lactate accumulation Mechanisms to explain lactate threshold: - low muscle glycogen, accelerated glycolysis, recruitment of fast twitch fibers, reduced rate of lactate removal

Describe acclimation and what specifically happens to the body during exercise in hot and cold environments.

Acclimation: rapid adaptation (days to weeks) to environmental change Heat acclimation requires exercise in a hot environment and it's the elevated core temperature that causes the adaptations Acclimation can be lost within days of inactivity - 10-12% increase in plasma volume (maintains blood volume, stroke volume, and sweating capacity) - earlier onset of sweating and a higher sweat rate (less heat storage, maintain lower body temperature) - reduced sodium chloride loss in sweat (reduced risk of electrolyte disturbance) - reduced skin blood flow You may start seeing lower heart rate and increase in plasma volume just after 3 days of heat exercise. After about 8 days you may start seeing increased sweat rate. RPE may change after about 5 days. After acclimation, core body temperature decreases as well as heart rate . Hot/Humid Environment: For first 30 minutes there is no significant difference in core temperature Sweat rate goes up rapidly within the first 15 minutes in a hot environment. After about 30 minutes, sweat is more concentrated because we are dehydrated, so we have to sweat more to compensate. Evaporative heat loss is not as effective in this case so our core body temperature increases. Physiological Response to Heat Load: - Data sends a message to the anterior hypothalamus, which then sends a message and triggers subcutaneous vasodilation and sweating Exercising in the cold can promote heat acclimation but not to the magnitude that heat exercise can. Cold Acclimation: - results in lower skin temperature which results in shivering (increased non-shivering thermogenesis) - maintain higher hand and foot temperature (improved peripheral blood flow) - improved ability to sleep in the cold (due to reduced shivering) - these adaptations begin within one week When exercising in the heat, you lose the ability to lose heat quickly. Core body temperature rises, increases the risk for hyperthermia and heat injury, higher sweat rate (as high as 4-5 L/hour), increases risk of dehydration. Exercise in a cold environment - Enhanced heat loss (reduces chance of heat injury) - May result in hypothermia (loss of judgement and risk of further cold injury) - Subcutaneous fat improves cold tolerance - Reduced dexterity in extremities (due to reduced blood flow and slower nerve transmission) - Risk of frostbite Physiological Response to Cold Stress - happens in the posterior hypothalamus - cold triggers response in P. hypothalamus which then causes a number of responses in an attempt to warm the body up (shivering, vasoconstriction, catecholamine and thyroxin release

Oxygen-Hemoglobin Dissociation Curve

At rest in the lungs(Arteries), the PO2 saturation is 100 At rest in the veins, the PO2 saturation is 40% If the PO2 of the blood is lower, say during exercise, there will looser oxyhemoglobin bonds which allows the oxygen to be unloaded to the tissues. At PO2 levels of 40 mm Hg or below, small increases in PO2 make for large changes in hemoglobin saturation. At PO2 levels of about 90 or greater, there are only small changes in hemoglobin concentration. Bohr Shift • Increase in temp • pH goes down (more acidity) • happens during moderate to high intensity exercise - oxygen is more loosely bound to hemoglobin, which means its more readily unloaded to the tissues

Describe DOMS and what it results from.

Delayed-Onset-Muscle-Soreness - appears 24-48 hours after activity - Not caused from lactic acid build up - It is caused from microscopic tears in muscle fibers or connective tissue which results in cellular degradation and an inflammatory response - eccentric exercice more damaging than concentric exercise

Describe the impact of detraining.

Detraining simply refers to the "use it or lose it" principle. Muscular strength adaptations made during resistance training exercise can be lost if exercise program stops. The rate of muscle atrophy and loss of strength with resistance training is slower compared to endurance training. Retraining following detraining is possible and quite often the body is able to train farther than they were before detraining.

Explain the effect of endurance training on VO2 Max.

Endurance training programs involving large muscle groups (i.e. running, cycling, swimming) for 20-60 minutes per session 3+ x per week, at an intensity between 50-85% VO2max typically increase VO2max. VO2 max can increase up to 15-20% given the person is your average individual and relatively sedentary. For those who already have high VO2 max values may only see about a 2-3% increase, and for those individuals who have low initial value may see up to 50% increase. Genetic predispositions come into play with VO2 max. Most of the elite male and female endurance athletes have a genetic predisposition to large cardiovascular capacity and a high percentage of slow twitch muscle fibers. These individuals are referred to as "high responders" to endurance training adaptations. Genetic predispositions account for about 50% of someone's VO2 max value.

Discuss how performance is affected when in a hot/cold environment.

Exercise performance is impaired when in a hot environment - Heat-related muscle fatigue (prolonged and intermittent exercise) - Accelerated glycogen metabolism (increase lactate accumulation) - Increased free radical production (damage to muscle contractile proteins) - Reduced muscle blood flow (during high intensity exercise) - High brain temperature reduces neuromuscular drive (reduction in motor unit recruitment)

Advantages vs. Disadvantages in training equipment

Free-weights: offers full range of motion, low costs, can be made specific to sport movement, but might put you at more risk for injury Machines: less risk of injury, generally safe, but does not offer full range of motion, high cost, not sport movement specific Isometric: minimal cost, less time required, but is not directly applicable to most sport activities, may be boring, progress more difficult to monitor

How would the base principals of training (overload, specificity, reversibility) be integrated into endurance training programs to see improvements in VO2 max?

In order to make any performance or physiological adaptations over time,for example increasing VO2 max, progressive overload of a system or tissues must occur through changes in intensity, duration, or frequency.

What is blood doping?

Infusion of RBCs to increase the hemoglobin concentration and therefore increase oxygen carrying capacity of the blood (can be autologous or homologous) - Shows massive improvement of aerobic performance that lasts 10-12 weeks Erythropoietin is the hormone that stimulates the production of RBCS, can lead to dangerous (even deadly) amounts of RBCs Little progress in testing for EPO or RBC infusion

Exercise Intensity(VO2Max) and Fuel Selection

Low intensity exercise (<30% VO2max) o Fats are primary fuel High intensity exercise (>60% VO2 max) o Carbohydrates are primary fuel "Crossover concept" : shift from fat to carb metabolism RER: .7-1 (Respiratory Exchange Ratio) o .7 relying more on fats o 1 more on carbs o .85 right in the middle using both

What are the research difficulties in this line of research and what can researchers do to combat this?

Most of the research in this area is short-term. It is difficult to find research that examines the long-term effects of certain ergogenic aids. The effect of an ergogenic aid depends on a number of variables including amount, subject, task, and use. This gives rise to a numerous potential of different outcomes for researchers and makes this like of research more difficult. Researchers must be very careful in designing experiments in order to not be "fooled" by the result. Researchers may choose to use a placebo as a treatment, and also have the study be double-blind, which means both the participant and the treatment administer are unaware of the treatment.

Does lactic acid cause muscle soreness?

NO • Lactate production in commonly believe to cause muscle soreness o Delayed onset muscle soreness (DOMS) o 24-48 after exercise • Physiological evidence does not support this calim o Lactate removal is rapid (within 60 min) following exercise o Power athletes should experience DOMS after every work out • Microscopic injury to muscle fibers leads to inflammation

What are the mechanisms which potentially impair strength development?

Neural factor: impaired motor unit recruitment (proposed that concurrent strength and endurance training impairs strength development because of neural factors) Low muscle glycogen content: due to successive bouts of endurance exercise (reduced intensity of subsequent resistance training) Overtraining: no direct evidence that concludes this affects strength development Depressed protein synthesis: endurance training adaptations concurrent with resistance training can interfere with protein synthesis following training

Detraining and change in VO2 max and other cardiovascular variables

Over the first two weeks of detraining there are fairly rapid decreases in cardiac output and SV max as well as VO2 max.

Describe the changes which occur in strength, fiber size, and fiber type with traditional resistance training.

Progressive strength training causes muscle hypertrophy and strength gains. Hyperplasia: increase in muscle fiber number within a specific muscle (controversial, more gains in muscle size probably due to hypertrophy) Hypertrophy: primary means of increasing muscle size during long term strength training - Enlargement of both type 1 and type 2 fibers(more so these type) - increase in myofibrillar proteins - increased number of cross bridges - increased ability to generate force High-load resistance training results primarily in gains in muscular strength Low-load resistance training results primarily in gains in muscular endurance, with less increase in strength. Similar to endurance training, resistance training for prolonged periods has been shown to have the similar effect of fast-to-slow. Although no increase in % of type 1 fibers, just a shift from type 2x to type 2a fibers.

Physical Activity Recommendations for Pregnant Women

Same recommendations as any other person - 150 minutes of moderate physical activity per week - If previously vigorously active, you may continue your normal activity levels so long as you pay attention to warning signs - About half of pregnant women do not engage in any moderate physical activity during pregnancy - Physical activity decreases significantly as pregnancy progresses and may be specific to trimester. Only about 15-20% of pregnant women are currently meeting the PA recommendations Gestational Diabetes Mellitus (GDM) 3-10% - in acute bout studies physical activity produced a short term "insulin-like" effect - in repeated bout studies PA improves blood glucose management and becomes somewhat of a training adaptation - studies show reduced risk of GRM pre-pregnancy, early pregnancy, and with walking Preeclampsia 3-7% - no cure for it, except to have the baby - PA prior to and during pregnancy related to reduced risk of developing it - however there may be a threshold for increasing risk of preeclampsia Common misconceptions - increased risk of miscarriage - increased chances of pre-term - increased chance of pre-natal complications with mother and baby

What are the physiological factors that cause an increase in VO2 max

Training induced increases in VO2 max can be due to 50% increased cardiac output (stroke volume), and 50% increased a-v O2 difference, or an increase in both. In shorter duration of training, increases in VO2 max are mostly attributed by an increase in cardiac output and a smaller contribution made by a-v O2 difference. During longer duration of training (28 months), increases in VO2 max can be mostly attributed to a-v O2 difference, and a smaller contribution made by cardiac output.

Are there age and gender related differences in thermoregulation during exercise?

YES to both; there is a caveat Gender: No, as long as gender is matched Age: as we age, we lose the ability to thermoregulate (more so because of physical decline) and lose the ability to acclimate due to factors related to aging

FEV1

forced expiratory volume is the volume of gas expired in one second during a forced (max effort) expiration from a full inspiration

Changes in Cardiovascular Variables During Exercise

o Group of 5 graphs on relationship between intensity and heartrate, stroke volume, CO, etc. o Stroke volume increases linearly until 40-50% of VO2 max then plateaus for the majority of population o Cardiac output is a combo of between heart rate and stroke volume

FVC or VC

the maximum amount of gas that can be expired after a maximal expiration

Redistribution of Blood Flow During Exercise

• As exercise intensity increases, the distribution of blood to skeletal muscles increases • Arterioles are responsible for the vasoconsctriction and vasodilation that controls this Cardiac Output increases 5 fold during heavy exercise Skeletal muscles increase about 20 fold in blood flow diverted to skeletal muscles **Study this table**

MVV (Maximal Voluntary Ventilation)

• MVV is an estimate of the total amount of air that can theoretically be moved in one minute L/min • MVV/VEMax • Test is 12 or 15 seconds and the values are extrapolated to 60 secs • In a healthy individuals MVV exceeds VEMAx by ~35% • This ratio helps us see whether lungs are limiting exercise performance

Lung Volumes and Capacities

• Vital capacity is the largest amount of air that can be measured by a spirometer • Residual volume is the dead space left in the lung after a maximal expiration • FEV1/ FVC • MVV/VEMax