# Physical Activity
## September 30th, 2020
- So, physical activity is important - why?
- It helps prevent cardiovascular and other diseases
- Lack of phsyical exercise is one of the big 4 reasons for preventable death
- It helps with mental illnesses, too
- Some immediate benefits:
- It reduces your stress level
- It improves sleep schedules
- It helps you to concentrate (it literally flows more blood to your braim)
- It improves your self-esteem
- Improves your resistance to mental and physical diseases
- Physical activity, though, is ANY body movement that enhances your health, while exercise is a specific type of PLANNED physical activity specifically set aside for your health
- As Americans, only 50% are meeting the 2008 U.S. physical exercise guidelines, only 24% are meeting aerobic and strength guidelines, and ~26% engage in no execise at all
- What are these guidelines? We're supposed to get 150 minutes of moderate-intensity physical activity EACH WEEK!
- Moderate intensity would be a heartrate of ~60-75% of your maximum heartrate, vigorous exercise is at ~75-95%
- The formula for your target heartrate USED to be:
```
lower limit = 0.64*(220 - age)
upper limit = 0.96*(220-age)
```
- Now, the updated formula replaces this with 207 - .7*age
- So, for a 20 year-old, you'd be looking at a 124-186 BPM target range
- "Being in this range is important because physical activity that's below the moderate level tends to have noticeably less benefit for cardiovascular activities, although it's still way better than nothing"
- REMEMBER: These are general
- Another way to tell your heart rate: if you can talk comfortably but not sing, it's a moderate activity; if you can only talk in short spurts, it's a vigorous activity
- There are 5 basic kinds of physical fitness:
- CARDIORESPIRATORY FITNESS is your ability to sustain an activity for an extended period of time
- These are "aerobic" activities that rely on the heart/lungs providing oxygen to the body, like running, stair climbing, etc.
- MUSCULAR STRENGTH is how much force a muscle is capable of exerting in a single contraction
- MUSCULAR ENDURANCE is how well your muscles can do something repeatedly
- FLEXIBILITY is your range of motion around a given joint
- "This is often blown off, but it's important for preventing injuries - runners can prevent tons of injuries just by stretching"
- BODY COMPOSITION is the ratio of your fat to muscle in your body tissues
- Your body composition can ABSOLUTELY change even if your weight doesn't, since you can replace muscle with fat or vice-versa
- So, regular physical activity gives us less risk of cancer/diabetes/heart diseases/etc., reduces osteoporosis, leads to longer life and better immune systems, etc.
- Reducing cardiovascular diseases comes from literally making your heart and lungs stronger muscles and more efficient, having increased "stroke volume" and increasing the amount of oxygen and bloom pumped
- It also comes from reducing hypertension (which is a big cause of stroke and heart attacks), and improves your blood lipids (increases HDL (high-density lipoprotein, "good cholesterol"))
- Exercise improves your immune system, too, by increasing your number of white blood cells and reducing body inflammation
- It reduces metabolic syndromes like type 2 diabetes and accompanying heart problems (high blood pressure, obesity, high levels of bad carbohydrates, impaired blood sugars)
- Exercise reduces obesity and burns excess calories, which helps with ALL of these
- "For weight loss, you should double how much exercise a normal person needs, i.e. 300 minutes of exercise per week, especially via high-intensity interval training where you alternate high-intensity workouts with moderate ones"
- Different activities burn different amounts of calories; 30 minutes of 3 MPH walking only burns 120 Calories, as opposed to 230 when walking at 4.5 MPH, or 400 when jogging
- Exercise prevents osteoporosis (i.e. low bone density) by increasing your bone mass via weight-bearing activities; higher bone density also increases hormone levels in both men and women
- Exercise improves mental health by reducing stress and anxiety, making sleep easier, improving depression, and ; people also tend to report higher self-esteem and energy levels after exercising
- Stress in particular is reduced by the body releasing neurotransmitters related to from exercise
- By getting more oxygen flowing, too, exercise even helps with focusing and thinking
- Finally, there seems to be a link between people who exercise and reduced risks of cancer
- Remember, diet is HUGE when it comes to keeping these benefits; you need a LOT of exercise to burn off a 300 Calorie latte, and removing those things from your diet can make a surprisingly large difference
- Now, how much you exercise and how you exercise is going to vary from person to person - "you do NOT want to go from not exercising at all to doing 300 minutes of high-intensity stuff all at once"
- If you haven't been exercising at all, start gradually by slowly replacing sedentary behaviors with walking or moving around more
- You should also start exercising your muscles with simple, low-weight exercises and getting used to proper techniques, as well as stretching to keep yourself safe
- When you're picking physical activities, you should pick things that are convenient and that you enjoy - if you hate the gym, go for a walk instead!
- "The best exercise is the one that you'll actually do for more than a few weeks!"
- If you can incorporate exercises into what you already do, too, that's a great way to get started; walk to class instead of taking the bus! If you're okay with looking strange, do squats when you're in line at the supermarket!
- Think about what your obstacles are to working out, like not being motivated or disciplined, not enjoying it, not having time or resources, etc. - then, come up with ways to overcome those
- If you have motivation issues, work out with friends! If you don't have time, incorporate exercise into your normal routines!