Energy Utilization

Physical activity

• body movement that expends energy (kcals)

Physical fitness

• good health or physical condition as a result of exercise and nutrition

Exercise

• structured or planned physical activity

Five Components of Physical Fitness

• cardiorespiratory endurance

  • ability to sustain cardiorespiratory exercise for an extended length of time

• muscular strength

  • ability to produce force for a brief period of time

• muscular endurance

  • ability to exert force over a longer period of time without fatigue

• flexibility

  • range of motion around a joint, improved with stretching

• body composition

  • the proportion of muscle, fat, water, and other tissue in the body

Benefits of Exercise

• impact on body composition

• reduced risk of chronic NCDs (non-communicable diseases)

• associated with reduced risk of some cancers

• bone health and bone mineral density

• improved immune system functioning

• improved sleep quality

• improved mental well being

Kind of exercise that is the best:

• based on all components of fitness

  • cardiorespiratory endurance

  • muscular strength and endurance

  • flexibility

• tailored and individualized according to needs

• consistent

• enjoyable

Cardiorespiratory Exerises

• continuous activities that use of large muscle groups

• typically aerobic exercise

• cardiorespiratory fitness measured by VO2 max

• the maximum amount of oxygen muscles can consume during exercise

• measured as volume of oxygen used per kg

• improves cardiorespiratory endurance

FITT acronym

• frequency, intensity (low, moderate, vigorous), time and type

  • intensity: rate of perceived exertion, a subjective assessment

Progressive Overload Principle

• body gradually adapts to activities during conditioning

  • doesn’t have to work as hard

  • fitness level plateaus

• gradually increase exercise demands by modifying F/I/T/T component

Anaerobic Energy

• fuels quick, intense bursts

• examples: strength(lifting weights), speed/sprinting, jumping

• anaerobic capacity: 10 seconds of maximal effort

  • amount of atp in muscle cells is limited

  • requires creatine phosphate in muscles

  • depleted in 10 seconds, regenerates with rest

Aerobic ATP production:

• requires oxygen → heavier breathing increases intake

• slower pace

• no longer maximal effort

Carbohydrates are a primary energy source

• CHO are the primary energy source during high intensity

  • mostly utilizing muscle glycogen rather than blood glucose

• use of glucose and glycogen affected by

  • intensity of exercise

  • duration of exercise

  • conditioning

• depletion of glycogen “hitting the wall”

  • carbohydrate loading

Carbohydrate Type(s) for exercise

• eat simple CHO and immeditaley following activity

• absorbed quickly and enter bloodstream

  • sports drinks

  • gels

  • bananas

  • bagels, bread(not whole grain or high fiber)

• eat whole grain and complex CHO several hours beforehand

  • absorbed more slowly

  • sustained source of fuel

  • too much fiber pre workout can cause GI symptoms/discofort

Fat Emerges as energy source over time

• fat as a fuel source depends on duration and intensity of exercise

• fat emerges as energy source for low to moderate intensity activity

• requires availability of oxygen

Protein needed primarily for

• muscle repair

• small quantities of protein used for energy

• exercise increases cortisol. stimulating protein turnover

• insufficient kcal and CHO intake, body will utilize protein

Pre activity intake

• allow sufficient time for food to digest before exercise

  • large meals :3-4 hours

  • smaller meals: 2-3 hours

  • liquids or snacks : 30 min-1hr

During exercise intake

• not needed if exercise <1hour

• exercise greater than an hour requires food intake to maintain BG levels

  • consume CHO every 15-20 mins

  • aim for 30-60g CHO per hour

Post Activity Intake

• recovery

• consume CHO to replenish glycogen stores (30-45 min after)

• consume protein + CHO to increase muscle protein synthesis

Fluid Needs and Exercise

• adequate intake prevents dehydration and electrolyte imbalances

• exercise induces greater losses of water and electrolytes

• greater losses occur in hot humid weather

• water sufficient if activity <60 min

  • longer duration: sports drinks that contain ions