Unit 7: Physical Activity

The Average Canadian?

North American Statistics

• 24% Americans inactive (self reported, 2005)• American Center for Disease Control

recommends 30 minutes of moderate-intensity physical activity per day, most days– 49% of Americans meet this

• Canada: 49% of us (aged 20+) are moderately active (2005)

Key definitions• Exercise: is a planned, structured and repetitive

activity aimed at improving physical fitness– Ex. Aerobics, spinning class, running 3 times/week

• Physical Activity: any active movement you do that spends calories– Ex. Running, aerobics, walking, stretching, sit-up,

racking leaves, gardening, cleaning

http://www.merthyr.gov.uk/NeedsAssessment/Health+and+Well-being/Physical+Activity.htm

Physical Activity

Key definitions

• Health: “...total physical, mental and social well-being” -WHO

• Physical fitness: how able you are to perform physically demanding tasks

Components of physical fitness

• Health related fitness: has four components– Cardiorespiratory fitness– Muscular strength and endurance– Flexibility– Body weight and composition

Components of physical fitness

• Performance-related fitness: includes the same as health-related PLUS:–Speed and power–Agility–Balance–Reaction time–Anaerobic power and capacity

Aerobic fitness• Fitness that relates to activities that train the

cardiorespiratory system. – Improves oxygen consumption in the body

• Uses aerobic metabolism– C6 H12O6 + 6O2 6H2O + 6CO2 + 38ATP

– Glucose + oxygen water + carbon dioxide + energy!

– Performed at moderate intensities for extended periods of time

– Raises heart rate, breathing rate, metabolic rate and body temperature

Anaerobic Fitness• Intense activity that often improves strength

power, speed, and muscle mass– Uses anerobic metabolism

• C6H12O6 → 2C3H6O3 + 2 ATP • Glucose → Lactic Acid + Energy

• These pathways are typically recruited– in the first 120 seconds of exercise– when exercise demand is increased – during short bouts of intense exercise

Benefits of Exercise

Improves the ability of the heart to functionLessened cardiovascular disease risk

Quiets the sympathetic nervous system Blood lipids improve

Increases HDL, decreases LDL, VLDL, total cholesterolIncreased insulin sensitivityIncreases metabolic rate, especially right after the

exerciseAssociated with decreased myocardial infarction risk

Benefits of Exercise

Lowers the incidence of some cancersBreast cancer

Psychological benefitsDecreases depression, reduces certain type A

behavioursImproves self-confidence and self-esteemActivity decreases anxiety

Look at how happy they are!

Benefits of Exercise

• Muscular improvements– Increases density, thickness and strength of

muscle– Improves ability of muscle, trains it against injury– Improves mobility and independence (especially

in the elderly)

Benefits of Exercise

• Bone health improvement– Weight bearing exercise increases density and

strength of bones– Therefore important in the prevention of

osteoporosis

Risks of Exercise• Most common risk = injuries– Most often effect the musculoskeletal system– Traumatic injuries ex. Sprained ankle, fractured arm

– Overuse injuries ex. Runner’s knee, tennis elbow

Risks of Exercise

• General Overstress– Recall that exercise does stress the body– May push your body over the edge if your body is

already too stressed• Can lead to illness ex. influenza

Risks of Exercise

Temperature injuryFrom being too hot or too cold

Can lead to hypothermia (decreased body temperature) or hyperthermia (elevated body temperature)

Can cause sudden deathIn people who are already at high risk

Risks of Exercise

• ***Overall, exercise reduces CVD risk. However, vigorous exercise increases risk of a myocardial infarction in people who

already have CVD

Determining if you are overtraining

• Exercise can become a compulsion: “I have to do it no matter what!”

• Overtraining signs include:– Persistent pain, especially of the joints– Increased difficulty performing a standard exercise

level– Increases susceptibility to infections. Ie. Influenza,

acne– Felling tired, lacking energy, lack of enthusiasm

• If you are experiencing these signs: REST!!!!

Exercise Recommendations

– Have a doctor examine you before you begin exercising if you are over 35 or at high risk

– Make sure that someone who specializes in exercise supervises you

– Increase activity level GRADUALLY!!

Exercise Recommendations

• Exercise 3-5 times per week • Exercise as part of a schedule that someone

enjoys has a much higher compliance rate • Pick appropriate exercises• ENJOY YOURSELF!!!!

Recommended training zoneIn each session you should be working for 20-60

minutes and at 60-90 % of maximum heart rateMaximum HR (MHR)= 220 – your age in years = MHRMHR X 0.6 = 60% of your MHRMHR X 0.9 = 90% of your MHR

To actually determine your heart rate, measure it at your pulseIn a ten second interval, count the number of beats

(start counting at one). Multiply that number by 6

Muscular Strength and Endurance

• Strength: the ability to produce a large amount of force in a single contraction

• Endurance: the ability to perform many repetitions with a sub-maximal resistance

Muscular Strength and Endurance:Recommendations

• Make sure you balance both sides of your body and muscles in different parts of your body

• Do at least one exercise for each major muscle group

• Do complimentary exercises– Ex. biceps curls after triceps extensions

• Do a full range of motion• Work larger muscles before smaller muscles• Maintain correct technique• Breathe!

Muscular Strength and Endurance:Recommendations

• Overall, no single well-planned program is superior to another

• Basic recommendation: – Moderate intensity resistance training– One set of 8-12 exercises done at least 2 times

per week– Schedule at least one day of rest between working

the same muscle group– Mix it up to avoid boredom and plateaus!

Flexibility

• Flexibility: the range of motion of a joint• Stretching is done to improve flexibility– Simplest stretching = static stretching

• Move slowly into the stretch and then hold it• Relax into the stretch• Only go as far as your body lets you at first

– Hold for 30 seconds

Flexibility

• Warming up should be done before performing any taxing exercise– Start with mild full body motions. Ex. Walking– Then, gentle movements. Ex. Slow shoulder circles

• = mobilization exercises, increase blood and nutrient supplies to joints and tissues

– Then, gently stretch the muscle– Work your way through most joints