HNSC Unit 10

Physical Activity

Increased Benefits of Physical Activity

• more restful sleep

• nutritional health

• bone composition

• immunity

• circulation

• self image

• longer life and better quality

Decreased Benefits of Physical Activity

• cancer risk

• CVD risk

• type 2 diabetes

• gallbladder disease

• anxiety/depression

Canada’s Guidelines

• for adults 18-64

  • 150 min of moderate to vigorous activity per week

  • add up activities in periods of at least 10 min

  • 2 days per week of muscle and bone strengthening activities

Fuel Use

• at rest

  • ½ fatty acids, other ½ mostly glucose, some AAs

• during activity

  • early minutes: majority from muscle glycogen

  • as activity continues: glucose and FAs

Anaerobic Activity

• no oxygen

• maximal exercise of short duration

• energy from glucose

• produces lactic acid

  • muscles use some, but when exceeds, sent to liver

Aerobic Activity

• moderate activity

• requires oxygen, produces carbon dioxide

• energy from glucose and fat

• highly trained muscles use less glucose and more fat than untrained

Carbohydrates

• diet strategies to maintain CHO conc.

• take in some glucose during activity

• eat CHO-rich foods within 2 hours post activity (boosts muscle glycogen stores)

• CHO loading

CHO Loading

• regimen of moderate activity, followed by eating high CHO diet

• allows muscles to store more glycogen (to nearly double normal muscle storage levels)

• benefits athletes in long duration activities (>90 min)

Fats

• high fat diets impair performance

• too low <20%kcals: may not take in adequate energy or nutrients

• recommendations: 20-30% cals from fat

Protein

• eating protein with CHO within 2 hours post activity:

  • can enhance muscle protein synthesis

  • CHO rich diet spares protein from being used as fuel

• protein needs:

  • higher for both endurance and strength athletes

  • no benefit beyond 1.6g/kg/day

Vitamins and Minerals

• supplements:

  • do not enhance performance if well nourished

  • can help if athlete is deficient

• vitamin E

  • may protect against exercise induced, oxidative stress; no improvement in perfomance

• iron

  • female athletes at special risk for deficiency

  • anemia can impair performance

Sports Drinks

• water, glucose, minerals, electrolytes

• benefits from glucose if activity >60min

  • helps maintain blood glucose

  • ~7% sugar: if too high, delays stomach emptying

  • sugar may add unwanted calories

Ergogenic Aids

• products that supposedly enhance performance

  • energy giving

• many are regulated under Natural and Non-perscription Health products in canada

• many have side effects

• most have been proven not effective and unnecessary

Amino Acid Supplements

• consumed for building larger muscles

• extra AAs do not lead to building muscle

  • they are stored as energy after the removal of N, increasing N excretion

• AAs compete for absorption

  • such supplements can limit the availability of other AAs

• a well balanced diet provides sufficient essential AAs to build muscles

Caffeine

• endurance athletes may get the benefit of energy boost but provides no advantages during high intensity

  • mechanism of action is not understood

• side effects:

  • dehydration, upset stomach, irritability, constriction of arteries

• common sources: coffee, energy drinks

Carnitine

• non-essential nutrient needed by our cells to transport fat molecules across the mitochondrial memb.

  • this logic is used to advertise the claim that carnitine increases fat burning

  • no evidence

• oral is not prohibited in international sports

• body can produce all it needs

Creatine

• some specific evidence exists that creatine enhances performance during sport

  • many studies show no such effect

• creatine metabolism leads to production of the toxin formaldehyde

  • long term safety is unknown

• may cause kidney damage

• not illegal in international competitions

Hormone Preparations

• anabolic steroid hormones

• naturally produced by male testes and adrenal glands, and female adrenal

• synthetic forms accelerate muscle growth

• banned from the olympics and condemned by the Canadian centre for ethics and sports because they give an unfair advantage to the athletes using such products

• side effects: liver tumors, heart disease, depression

Human Growth Hormone

• naturally produced during rest, especially after activity

• synthetic forms lead to abnormal enlargement of organs or bones

• banned by olympics and CCES

• side effects: diabetes, heart diseases, thyroid issues, mensural issues