kin week 6

18th century- started with breathing, physiology of animals’ oxygen consumption and carbon dioxide production 

Start of exercise research: 1900-1950

• Microcirculation

• Energy metabolism

• Oxygen consumption 

• Lactate production

• Oxygen debt 

• Ergogenic acids

• Physical fitness 

1950-2000: significant discoveries

• Link between physical activity and chronic disease 

1990: governments acknowledged these findings:

1. Physical inactivity is a major risk factor for cardiovascular disease

2. Moderate levels of regular physical activity confer significant health benefits 

3. Regular physical activity can not only reduce risk of heart disease, but also diabetes, hypertension, colon cancer, and weight 

200-today: recent events 

• Deeper exploration into effects of types of exercise 

• Physical activity mitigates degenerative diseases and shown to prolong life 

• Genetic influences on the bodies ability  to create muscle and cardiovascular development, and metabolism

• Technological advancements help us stay active 

Exercise research:

Laboratory work- helps eliminate extraneous factors like temp and humidity that can affect our responses to exercise 

• Cardiovascular fitness and Vo2 max

• Ergometers

• Biopsies

• Body consumption analysis 

• Animal models 

Cardiovascular fitness- can be assessed by direct measurement or est oxygen consumption 

 Vo2 Max- most widley accepted method to measure cardiovascular fitness. Begins with someone exercising while the intensity of the exercise gradually increases until they can no longer perform at that intensity 

Ergometers- used to measure the external work performed by the muscle in an exercise 

Ex: treadmill, leg or arm cycle, swimming flume 

Biopsies- draw blood for lactic acid ans glucose levels or take muscle biopsies to examine change in muscle structure and damage after exercise 

Ergometers and biopsies work together usually 

Body composition analysis- another way to measure a persons composition of lean muscle to fat 

• Underwater weighing 

• Bod pod

• Calipers

• BIA

Animal models- mammals (rats) that match humans as closely as possible for things not easily observable like brain liver or heart 

Field work- (outside lab) via BMI, physical education fitness test, PACER test, and technology trackers helpful for real life variables and applications  

• BMI- good screening tool for risk of obesity related diseases but not at a body composition. Over 30 is obese. Body mass in kilo/square of height in meters 

• PE fitness test- mile time, crunches, pushup, flexibility 

• PACER test- requires little space and can accommodate many people 

• Technology tracker- heart rate, motion sensor, pedometers, accelerometers, and can all then be used to calculate caloric expenditure and movement tests 

Physiological systems-respond and adapt to physical activity. All systems work independently

Muscle types:

Smooth- muscles found in the digestive tract, uterus, and blood vessels and contract in waves to move thing along, involuntary muscles w no conscious control over it 

Cardiac- muscles of the heart, involuntary with no conscious control over it 

Skeletal- voluntary muscle where you have control over movement and what you have attached to bones for skeletal movement 

Fast twitch- fast glycolytic and fast oxidative glycolytic 

Fast glycolytic- use anaerobic energy (no oxygen)

Fast oxidative glycolytic- use anaerobic and aerobic energy (oxygen)

Slow twitch- use aerobic energy systems 

Muscular strength- maximum force exerted by a muscle or group of muscles, usually cant hold that long, like weightlifting 

Strength training (anaerobic)- muscles are performing at a low frequency, high force output activity that induces hypertrophy 

Tradeoff- mitochondria density decreases causes decrease in muscular endurance capacity 

Muscular endurance- muscles ability to exert force repeatedly over long period. Like a marathon 

Endurance training (aerobic)- muscles are performing at a high frequency low force output activity that createes more oxidative metabolism 

Tradeoff- does not significantly increase cross-sectional muscle fiber through hypertrophy 

Resistance training:

Isometric- tension without changing in muscle length

Isotonic- changing in muscle length without changing external gravitational resistanceisokinetic- changes in muscle length with joint movement at a constant angular velocity 

Two general strength training principles:

1. Progressive overload

2. Specificity 

Cardiovascular system reaction to physical activity- increase the volume of blood pumped and the distribution of blood to active muscles 

Blood flow distribution:

At rest- 

During heavy exercise- 

Respitory: regulates the exchange of gases between the external environment and the internal environment 

Ventilation threshold- during physical activity, your breathing rate increases rapidly until it reaches a plateau at around 1 minute called the ventilation threshold. 

Temperature effects on exercise: during exercise your body produces heat

To lose heat:

1. Bring warm blood to the surface of the skin cools 

2. Evaporation of sweat from your skin cools 

If its hot or humid- our first cooling mechanism of bringing warm blood to the surface of our skin doesnt work as well. You will sweat a lot to try and compensate

If its cold or dry- provide an ideal environment for exercise 

If your cold and wet- heat loss is dramatically increased bc water is a great heat conductor. Ur body must burn use energy to keep your core temp warm through shivering, but that causes fatigue 

Nutrition:

Carbohydrates intake is necessary for optimal performance and health 

Glycogen is stored in skeletal muscles and liver as energy 

Carbo-loading- only effective for activities that last more than 2 hrs bc we have 1.5 hrs stored in our body 

Active people carb recommendations 

1. Eat between 55-60 percent of their calories as carbs 

2. Eat carb dense meals after exercise to restore glycogen levels 

Protein is necessary for repairing and replacing damaged proteins, aiding adaptations, and maintaining functioning of metabolic pathways. 

Protein diet for:

Average person- 0.8 kg/day

Elite endurance athlete- 1.2-1.4g/kg/day

High intensity strength training- 1.2-1.7g/kg/day

Meat eating americans- average 2.5g/kg/day (150g)

Fluid intake is necessary for optimal performance and health 

Iron intake is necessary for optimal performance and health. It helps transport oxygen in blood thru hemoglobin 

Those who suffer from low iron most are women and girls because:

1. Menses (period)

2. Dietary issues via calorie restriction and eating non-heme iron sources 

General events of the sweat solution and reason wy the study of dehydration and the development of gatorade began 

The study of dehydration and the development of Gatorade began in the 1960s at the University of Florida. The primary motivation was to address dehydration and electrolyte imbalances in athletes, particularly football players who were losing significant amounts of fluids and electrolytes during intense physical activity in hot conditions.

Dr. Cade and his research team found that simply replenishing lost water wasn't enough for recovery, as athletes were also losing vital electrolytes like sodium and potassium through sweat. This led to the creation of a rehydration solution with water, sugar, and electrolytes that could help restore the body’s balance more effectively.

The result was Gatorade, named after the University of Florida Gators, which quickly became popular among athletes due to its effectiveness in preventing dehydration and improving performance.

Physical activity, health, and fitness 

1. Recommended amount of physical activity for adults: 150-300 minutes of moderate

2. intensity or 17-150 minutes of vigorous intensity