Physical Activity and Nutrition Notes

Fitness

• Fitness is defined as the ability to perform routine physical activity without undue fatigue.

Health Benefits of Physical Activity

• Sleep

• Mood

• Exercise improves flexibility and balance

• Exercise increases the sensitivity of tissues to insulin and decreases the risk of developing type 2 diabetes.

• Exercise reduces the risk of cardiovascular disease because it strengthens the heart muscle, lowers blood pressure, and increases HDL (good) cholesterol levels in the blood.

• Regular exercise reduces the risk of colon cancer and breast cancer

• Exercise increases muscle mass, strength, and endurance.

• Weight-bearing exercise stimulates bones to become denser and stronger and therefore reduces the risk of osteoporosis.

• The strength and flexibility promoted by exercise can help improve joint function.

Physical Activity Guidelines for Americans

• Every day - Choose an active lifestyle and engage in flexibility activities.

  • Integrate activity into your day: walk a dog, take the stairs, stand up whenever possible.

  • Stretching exercises lend flexibility for activities such as dance, but minutes spent stretching do not count toward aerobic or strength activity recommendations.

• 5 or more days/week-Engage in moderate or vigorous aerobic activities.

  • Perform a minimum of 150 min of moderate-intensity aerobic activity each week by doing activities like brisk walking or ballroom dancing; or, 75 min per week of vigorous aerobic activity, such as bicycling (>10 mph) or jumping rope; or a mix of the two (1 min vigorous activity = 2 min moderate).

• 2 or more days/week - Engage in strength activities.

  • Perform muscle-strengthening activities that are moderate to high intensity and involve all major muscle groups.

• Do seldom - Limit sedentary activities.

  • Limit TV or movie watching, leisure computer time.

  • For most men and women, aged 18 to 64 years.

Intensity of Physical Activity

• Table 10-1: Intensity of Physical Activity

  • Light:

    • Breathing and/or Heart Rate: Little to no increase

    • Perceived Exertion (on a Scale of 0 to 10): <5

    • Talk Test: Able to sing

    • Energy Expenditure: <3.5 cal/min

    • Walking Pace: <3 mph

  • Moderate:

    • Breathing and/or Heart Rate: Some increase

    • Perceived Exertion (on a Scale of 0 to 10): 5 or 6

    • Talk Test: Able to have a conversation

    • Energy Expenditure: 3.5 to 7 cal/min

    • Walking Pace: 3 to 4.5 mph (100 steps per minute or 15 to 20 minutes to walk 1 mile)

  • Vigorous:

    • Breathing and/or Heart Rate: Large increase

    • Perceived Exertion (on a Scale of 0 to 10): 7 or 8

    • Talk Test: Conversation is difficult or "broken"

    • Energy Expenditure: >7 cal/min

    • Walking Pace: >4.5 mph

How do muscles adapt to exercise?

• Overload principle = the body will adapt to the stresses placed on it.

• Stress or overload during exercise causes muscles to adapt by increasing in size and strength = hypertrophy.

• When muscles are not used, they atrophy = become smaller and weaker.

• Exercise builds and maintains muscles. People who are fit have a greater proportion of lean body tissue than those who are not fit.

• Building muscle - hypertrophy

• Losing muscle -> Atrophy

How does aerobic exercise help your heart?

• Cardiorespiratory Endurance is characterized by:

  • Increased heart strength and stroke volume

  • Slowed resting pulse

  • Increased breathing efficiency

  • Improved circulation and oxygen delivery

  • Reduced blood pressure

  • Increased blood HDL cholesterol

What is a good diet for an athlete?

• Sugar (carbs)

• Protein

• Healthy fats

• Water/electrolytes

Fluid Needs During Physical Activity

• During exercise, water is needed to:

  • Eliminate heat

  • Transport oxygen and nutrients to the muscles

  • Remove waste products such as lactic acid from the muscles.

  • The ability to do this depends on hydration levels.

• If heat cannot be lost from the body:

  • Body temperature rises

  • Exercise performance as well as health can be impaired

Suggested Hydration Schedule for Physical Activity

• Table 10-8: Suggested Hydration Schedule for Physical Activity

• The amount of fluid required for physical activity varies by the person's weight, genetics, previous hydration level, degree of training, environmental conditions, and other factors.

  • 24 hours before activity:

    • Recommendation: 5 to 7 ml/kg body weight

    • Common Measure: 1 oz/10 lbs

    • Example: 70-kg Athlete: 1/2 to 2 c

    • Example: 55-kg Athlete: ≈1 to 1/2 c

  • 2 hours before activity:

    • If heavy sweating is expected, additional 3 to 5 ml/kg

    • ≈0.6 oz/10 lbs

    • ≈1c (9 ounces)

    • ≈1 c (7 ounces)

  • During activity:

    • Limit dehydration to <2% body weight

  • After activity:

    • Drink ≥2 c for each pound of body weight lost

• A personal hydration plan, based on prior measures of fluid loss (weight) during the activity, is recommended.

• Thirst lags behind fluid loss and should be quenched immediately.

Water Loss

• Weigh yourself before and then after exercise.

• For every pound of weight lost drink 2 X 8 fl. oz. of water

Who needs a sports drink?

• They both need to replace fluids

Selecting Sports Drinks

• Fluid

• Glucose

• Percentage glucose

• Sodium and other electrolytes

• Psychological edge

Other Beverages

• Carbonated beverages

• Caffeine

  • Moderate doses

  • Excess sugar

• 100% fruit juice

  • Excess sugar

• Alcoholic beverages

  • Diuretic ->400 my before working out

Carbohydrates, Fats and Proteins in an Athlete’s Diet

• Glucose

• Glycogen

  • Can increase glycogen stores by doing Carb overload to max carb stores .

  • glucose ↳ Glycogen

Glucose: A Major Fuel for Physical Activity

• Liver glycogen is for the brain/nerves & RBC

• Muscle glycogen

  • Retains glycogen for own use

• Glycogen stores are limited.

• #1 Priority Last priority *Braim ↓ Energy

Glycogen-Before and After Physical Activity

• These electron micrographs magnify part of a muscle cell by 20,000 times, revealing the orderly rows of contractile structures within. The dark granulated substance is glycogen. In the photo on the left, the cell's glycogen stores are full; on the right, they have been depleted by exercise.

• The orderly horizontal rows that appear to be striped at intervals are protein structures that contract the muscles.

• The black oblong rows between the contractile structures contain much of the muscle's glycogen. More glycogen granules (black dots) are also scattered within the contractile parts (visible at left but depleted at right).

The Effect of Exercise Intensity on Fuel Use

• Percentage of ATP from different nutrients

  • Rest: Fatty acids

  • Moderate-intensity activity: Glucose and Fatty acids

  • High-intensity activity: Glucose

Carbo-Loading

• High-fat diet: Maximum endurance time: 57 min

• Normal mixed diet: Maximum endurance time: 114 min

• High-carbohydrate diet: Maximum endurance time: 167 min

Carbohydrate Recommendations for Athletes

• Postpone fatigue and maximize performance

• Need for abundant carbohydrate

• Glucose before activity

• Glucose during activity

• Glucose after activity (1-2 hours)

Examples of High-Carbohydrate Pregame Meals

• (at 1 hour before exercise) 200-calorie meal:

  • 30 g carbohydrate

  • 1 small peeled apple

  • 4 saltine crackers

  • 1 tbs reduced-fat peanut butter

• (1-2 hours before exercise) 500-calorie meal:

  • 90 g carbohydrate

  • 1 medium bagel

  • 2 tbs jelly

  • 1 c low-fat milk

• (2-3 hours before exercise) 800-calorie meal:

  • 135 g carbohydrate

  • 1 large restaurant-style burrito, with

    • 12-inch soft flour tortilla

    • Rice

    • Chicken

    • Black beansb

    • Pico de gallo (fresh tomato sauce)

  • 14 ounces lemonade

Nutritious High-Carbohydrate Meals for Athletes

• 2,600 Calories

  • 62% cal from carbohydrate (403 g)

  • 23% cal from fat

  • 15% cal from protein (96 g)

  • Breakfast:

    • 1 c shredded wheat

    • 1 c 1% low-fat milk

    • 1 small banana

    • 1 c orange juice

  • Lunch:

    • 1 turkey sandwich on whole-wheat bread

    • 1 c 1% low-fat milk

    • Large bunch of grapes

  • Snack:

    • 2 c plain popcorn

    • A smoothie made from:

      • 11/2 c apple juice

      • 11/2 frozen banana

  • Dinner:

    • Salad:

      • 1 c spinach, carrots, and mushrooms

      • 1/2 c garbanzo beans

      • 1 tbs sunflower seeds

      • 1 tbs ranch dressing

    • 1 c spaghetti with meat sauce

    • 1 c green beans

    • 1 slice Italian bread

    • 2 tsp soft margarine

    • 11/4 c strawberries

    • 1 c 1% low-fat milk

• 3,300 Calories

  • 63% cal from carbohydrate (520 g)

  • 22% cal from fat

  • 15% cal from protein (125 g)

  • The regular breakfast plus:

    • 2 pieces whole-wheat toast

    • 1/2 c orange juice

    • 4 tsp jelly

  • The regular lunch plus:

    • 1 turkey sandwich

    • 1/2 c 1% low-fat milk

  • The regular snack plus:

    • 1 c popcorn

  • The regular dinner plus:

    • 1 corn on the cob

    • 1 slice Italian bread

    • 2 tsp soft margarine

    • 1 piece angel food cake

    • 1 tbs whipping cream

Protein to build muscle

• How?

• Need high quality protein in diet

• Repeated muscle contractions (Animal protein) ->digestable :Absorbable

Recommended Protein Intakes for Athletes depends on the sport

• Table 10-6: Recommended Protein Intakes for Athletes

• RECOMMENDATIONS (g/kg/day)

  • DRI recommended intake: 0.8

  • Recommended intake for power (strength or speed) athletes: 1.2-1.7

  • Recommended intake for endurance athletes: 1.2-1.4

  • U.S. average intake

• PROTEIN INTAKES (g/day)

  • Male (70 kg)

    • DRI recommended intake: 56

    • Recommended intake for power (strength or speed) athletes: 84-119

    • Recommended intake for endurance athletes: 84-98

    • U.S. average intake: 102

  • Female (55 kg)

    • DRI recommended intake: 44

    • Recommended intake for power (strength or speed) athletes: 66-94

    • Recommended intake for endurance athletes: 66-77

    • U.S. average intake: 70

• Daily protein intakes are based on a 70-kilogram (154-pound) reference man and a 55-kilogram (121-pound) reference woman. Other individuals must calculate their recommended intakes using the numbers of column 1. (For kg divide lb by 2.2.)

Timing of Protein intake

• Building new muscles highest in 2 hours after

• Last 24-48 hours after activity

• 20 grams I small ahy breast 1202 yogurt

Iron – A Mineral of Concern

• Iron

• Deficiency impairs performance

• Sports anemia

• Groups at risk for deficiency

• Vitamin C Most↓ Importan

Sports Anemia

• Normal vs Sports anemia

Foodborne Illness

• Symptoms

  • Nausea

  • Vomiting

  • Diarrhea

  • Fever

  • others

• Statistics

  • CDC estimates, each year:

    • 76 million people get sick

    • 300,000 are hospitalized

    • 5,000 Americans die

• Most susceptible…

  • Infants/children

  • Elderly

  • Immuno- compromised

What is foodborne illness?

• An infection or illness often caused by bacteria or a virus which is transmitted by food.

• Cause

  • Microbes

  • Toxins

Four essentials for microbial growth

• Nutrients

• Water

• Temperature

• Time

Prevention

• FIGHT

  • CLEAN- Wash hands and surfaces often.

  • SEPARATE- Don't cross-contaminate.

  • COOK- Cook to proper temperatures.

  • CHILL- Refrigerate promptly.