HK test 1
Immediate Phosphagen
-substrate: ATP, PCr, glucose -relative rate of ATP production-very fast -duration at max pace- 0-30 secs -limiting factors: PCr depletion -ex. weight lifting, short sprints, jumping, power lifting
TRAINING-INDUCED METABOLIC ADAPTATIONS
1. Muscle glycogen stores increase with endurance training 2. Muscle phosphocreatine (PCr) stores may be increased by power and short sprint training 3. An endurance-trained athlete begins to sweat earlier and sweats more during exercise than an untrained person
energy system usage in 10 second sprint
53% phosphagen system 44% anaerobic glycolysis 3% aerobic system
why is there a decrease in max HR as we age?
A decrease in neural signals/input from the brain to the heart which results in lower cardiac output.
two changes found in older adults brain function/structure after participating in extended aerobic training
An increase in the volume of the hippocampus which is a region of the brain that is involved in relaying short term memories to the cerebral cortex, and in addition those who participated longer showed more volume in the cerebral cortex which stores long term memories.
what is an effective aerobic training program for children?
At least 3 times per week having children exercise for around 40-60 minutes. Children should always be active but a specific program for aerobic training should last around 12 weeks for best results.
Overload
Athletes frequently experience a plateau in performance if training loads are not continually adjusted to accommodate recent adaptations and increased work capacity.
Periodisation
Athletes frequently train in weekly, monthly, or seasonal cycles, varying the intensity and volume of training to achieve their specific goals. Short cycles (1-2 wk) are called microcyles, and longer periods (2 wk-2 mo) are called macrocycles
carbohydrates used to synthesize ATP:
Carbohydrate (i.e., glucose) can be used to synthesize ATP either anaerobically or aerobically.
cardiovascular function VO2 max uptake
Cardiac output and oxygen consumption are linearly related. In other words, a high V. O2 max requires a large cardiac output. Cardiac output is a function of both HR and SV [cardiac output (L/min) = HR × SV]. Cardiac output increases linearly with increasing work rate and reaches a plateau at maxi- mum exercise capacity. During maximum exercise, cardiac output may reach values approximately four to eight times resting levels (figure 11.9c). Cardiac output represents the ability of blood to circulate and to deliver oxygen to the working muscles and is a major limiting factor for endurance-exercise capacity.
polyarticular muscles
Cross more than 2 joints, Also referred to as long restrictors, considered to maintain Type I, group dysfunctions
Monoarticular muscles
Cross only one joint
what are two reasons for a decrease in VO2 max during aging of a sedentary individual?
Decline of oxidative capacity for skeletal muscle, total body loss of muscle mass, as well as declines in heart rate and maximum cardiac output.
what suggests there are factors other than stroke volume and haemoglobin that limit aerobic fitness in women?
Differences in aerobic fitness persist even when haemoglobin levels have been reduced in men so that they are the same as women.
what time in life is there a difference in exercise capacity between boys and girls?
During puberty and towards the end of puberty. Men have a high percentage of type II fibers and women have a higher percentage of type I fibers, in addition, thoracic growth boys experience during puberty is greater than girls. Based on the graphs from the reading, mid to later puberty of girls and the beginning of puberty in boys in the range of when their running speeds differ the most because girls gain more fat, hormones and other changes, while boys gain more lean muscle mass and testosterone.
Anaerobic Glycolytic System
Fuel: Glucose or glycogen ATP production: fast ATP Cap.: 2-3 moles Intensity: High, minutes less than 3 limiting factors: lactic acid accumulation Ex. short sprints/track races
causes of fatigue during exercise: very prolonged
Glycogen depletion Dehydration Increased body temperature Low blood glucose levels Disturbance of blood amino acid levels
two considerations that should be followed when prescribing exercise to older adults?
Having low muscular strength and endurance, and the possibility of them having slower reaction times as well as impaired coordination.
muscle fiber type: Type I, or slow oxidative fibres (ST)
Highest oxygen supply, smallest in size and slowest in contraction speed
causes of fatigue during exercise: prolonged, moderate to high intensity
Moderate lactate accumulation Partial glycogen depletion Dehydration Disturbance of chemical gradients across cell membrane
isometric contraction
Muscle contracts but there is no movement, muscle stays the same length
how much can muscular strength increase after several months of training?
Muscular strength many increase by 20% to 100% over several months of resistance training.
what accounts for improvement in muscular strength in previously sedentary individuals after isometric and isokinetic strength training?
Neural adaptations from the training as well as muscle hypertrophy.
Training Variables
One can manipulate several variables when design- ing an exercise-training program: type of exercise (mode), duration, intensity, and frequency
causes of fatigue during exercise: longer, high intensity
PCr depletion High lactate levels Disturbance of chemical gradients across cell membrane
single indicator of adolescent fitness
Peak oxygen uptake (peak V. O2)
causes of fatigue during exercise: brief, high intensity
Phosphocreatine (PCr) depletion Moderate to high lactate levels Disturbance of chemical gradients across cell membrane
reasons to measure exercise capacity:
Precise measurement of aerobic and anaerobic power or anaerobic capacity allows evaluation of an individual's metabolic abilities and is an indication of their current state of fitness as well as the effectiveness of their training program. Such testing can also be used in talent-identification programs for some sports
pulmonary function VO2 max uptake
Pulmonary ventilation is the volume of air brought into the lungs per minute and is a function of both respiratory rate and the depth of each inspiration (i.e., the tidal volume). At maximal exercise, high rates of ventilation are usual and may be 20 to 25 times resting values. The large increase in pulmonary ventilation ensures that blood flowing through the lungs is almost fully saturated with oxygen, even at maximum exercise.
training specificity
Skeletal muscle responds specifically to the physiological and metabolic demands of exercise. Thus, training must reflect the specific energy demands of the activity.
Individualisation
Training adaptations are best achieved when the program is individualised to the specific needs of the individual athlete.
T/F: Even at birth boys tend to have a greater amount of muscle compared with girls.
True
do boys or girls have a higher cardiac muscle max and cardiac maximum output
boys
the volume of blood pumped through the body per minute is called?
cardiac output
sarcomere: z disc, a band, i band, h zone, myosin, actin, elastin, tropomyosin, troponin
contractile unit of a muscle fiber
do girls or boys have a higher resting heart rate?
girls
what is glucose stored in the muscles called?
glycogen
steady rate exercise
ie. jogging, swimming etc; submaximal exercise reaches a plataeu. VO2 causes vasodilation in muscles, reduces TPR to enhance blood flow to vasculature and the rhythmic contractions of the muscles also increases venous return. blood pressure rises and stays relatively constant.
Hyperplasia
increase in the number of muscle fibers due to exercise
eccentric contraction
muscle lengthens as it maintains tension
isotonic contraction
muscle shortens because muscle tension exceeds load
acute muscle soreness
soreness or pain felt during and immediately after an exercise bout, not the same as DOMS
4 training principles
specificity, progression, overload, and individualisation
muscle power is produced through what two things
strength and speed
Muscular strength
the maximum force that can be produced by a muscle or muscle group in a single movement
fast twitch muscle fibers
white muscle fibers that contract rapidly and forcefully but fatigue quickly; usually recruited for actions requiring strength, power, or speed
Anaerobic Power Tests
10 s and 30 s cycle ergometer tests in which the participant pedals as fast as possible on a special cycle ergometer equipped with a work monitor to measure power and work
energy system usage in a 30 second sprint
23% phosphagen system 49% anaerobic glycolysis 28% aerobic system
motor unit
A motor neuron and all of the muscle fibers it innervates
Endurance Exercise in Children
Children's aerobic and anaerobic performance is different from that of adults. The physiological responses to exercise alter as children progress into adolescence and on into adult life. This next section provides an overview of these changes and the child-adult differences.
pulmonary differences between boys and girls
During puberty, thoracic growth is greater in boys. When coupled with a greater muscle mass, boys have approximately 25% greater lung volumes than girls who are matched for height.
two reasons boys have higher cardiovascular function than girls
Girls have a higher resting heart rate which impedes their recovery and endurance in comparison to boys. Boys also have a higher cardiac muscle mass and a higher maximal cardiac output. This strengthens their contractions and pumps more blood to their muscles which carries oxygen which is a key component in ATP production and endurance.
Reversibility
Training adaptations last only as long as the physiological and metabolic demands of exercise continue (i.e., as long as training is maintained at a certain intensity and volume)
T/F: Even women who are elite track athletes have muscle fibres that are 70% to 80% of the size of those in male athletes
True
biarticular muscles
cross and act on two different joints
true/false: when doing a 10 second sprint the only energy system contributing to resynthesis is the immediate phosphagen system
false
true/false: in meeting the energy demands of exercise, carbohydrates, fats and proteins are transformed directly into ATP
false, they are broken down and energy is released from their chemicals bonds and is used to synthesize ATP
skeletal muscle superficial to deep
fascia, whole muscle, epimysium, muscle fasicle, perimysium, muscle fiber, endomysium, myofribril, sarcomere and myofilaments
Fats and proteins used to synthesize ATP:
fats in the form of fatty acids and proteins in the form of amino acids can be used to synthesize ATP only via oxidative respiration
oxidative (aerobic) energy system
fuel: glucose, fats, proteins ATP production: slow duration: more than 3 minutes limiting factors: glycogen depletion ex. soccer games, cross country, swimming
differences in younger and older people increasing training
in younger individuals, changes in V. O max are closely related 2to both the total amount of exercise and training intensity. Increases in V. O max in the range of 20% 2 to 40% may occur in the older adult after endurance training.
training principle in which you make sure each athletes personal needs are considered
individualisation
Excessive frequency, volume, or intensity of training, resulting in fatigue (which is also caused by a lack of proper rest and recovery) is called?
over training
maximal exercise
oxygen consumption continues to increase until a maximal value (VO2max) is achieved. During supramaximal exercise, additional ATP above that produced by oxidative metabolism is generated via anaerobic glycolysis.the highest intensity, greatest load, or longest duration exercise of which an individual is capable
the slight discomfort that all exercisers and athletes, but especially people who aren't fit, feel at the start of exercise is due to what?
oxygen deficit
components of VO2 max uptake
pulmonary function, cardiovascular function
aerobic power
rate of energy release by oxygen-dependent metabolic processes
anaerobic power
rate of energy release by oxygen-independent metabolic processes
slow twitch muscle fibers
red muscle fibers that are fatigue resistant but have a slow contraction speed and a lower capacity for tension; usually recruited for endurance activities
Anaerobic Power and capacity
refer to exercise capacities in activities requiring energy production by the phosphagen and anaerobic glycolytic systems, such as brief, very intense exercise. Anaerobic power is the maximum or peak power (expressed in watts), usually occurring in the first 2 to 5 s, that can be achieved in an all-out exercise test. Anaerobic capacity represents the total amount of work, expressed as watts or kilojoules, that can be accomplished in a specified time, usually 30 to 60 s.
VO2 max test
the participant starts to exercise at a comfortable pace. Exercise intensity then increases progressively until the participant can no longer continue to exercise at the given pace. This end point is called volitional exhaustion.
muscle fiber type: Type IIb, or fast glycolytic fibres (FTb)
large, fast forceful contraction, high in glycolytic capacity, moderate resistance to fatigue
differences in muscle fiber distribution between men and women
men have a lower proportion of Type I fibres Type II muscle fibres of young men are bigger than their Type I fibres, something that is not evident in young women
muscle contraction steps
1) Motor neuron releases acetylcholine into the neuromuscular junction and causes the depolarization of the sarcolemma. 2) Depolarization spreads down the sarcolemma to the T-tubules, triggering the release of Ca2+ ions. 3) Ca2+ binds to troponin, causing a shift in tropomyosin and exposure of the myosin-binding site on the actin filament. 4) Shortening of the sarcomere occurs as the myosin head binds to the exposed sites of actin, forming a cross-bridge and pulling the actin filament along the thick filament, resulting in contraction. 5) Muscle relaxes when acetylcholine is degraded by acetylcholine esterase and the allowing Ca2+ is brought back into the SR. ATP binds to myosin head, allowing it to relax from actin.
V O2 max
The highest rate of oxygen transport and utilization achieved at maximal physical exertion.
Periodisation of Training
The organized division of training into blocks, each with a goal and time-frame and helps athletes reach peak form in time for a major competition
muscle fiber type: Type IIa, or fast oxidative glycolytic fibres (FTa)
Tired easily, largest, fastest, produce lots of lactic acid
what is an effective resistance training program for children?
Two times per week with low-moderate weights but higher repetitions.
DOMS
delayed onset muscle soreness;muscle discomfort 24-36 hr after exercise due to oxygen deficit and lactic acid production
cocentric contraction
shortening of muscle
size principle of motor unit recruitment
units recruited start with smaller type I, then increase to type II, etc the largest and strongest FTb fibres are recruited for forceful contractions above 70% of maximum strength.
Reasons for decreases in exercise capacity in eld
}physically dependent (those who are debili- tated by disease), } physically frail (those with conditions affecting functional capacity in tasks of daily living), } physically independent (the majority of older adults who are free from disease but do not exercise regularly), } physically fit (those who are sufficiently physi- cally active to achieve health benefits), and } physically elite [a small group of people who train intensely, usually for competitive sport (e.g., masters athletes) or adventure recreation].
factors which promote hypertrophy
}the number of repetitions or times a weight is lifted; } sets or groups of repetitions; } training volume or total amount of work per- formed, which is the product of the number of repetitions and the number of sets; and } intensity or resistance.
