# Physical Activity (cont.)
## October 1st, 2020
- TODO: Read the slides and then fix this; the lecturer was going pretty fast
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- So, we covered some physical fitness stuff last lecture, but let's keep going!
- When you start exercising, you don't to just say "I want to get more fit, somehow;" you want to set goals - and you specifically want to set SMART goals:
- SPECIFIC
- MEASURABLE ("I'll improve my mile running time by 1 minute")
- ACTION-ORIENTED ("I'll meet with my fitness trainer", have a clear action to take)
- REALISTIC
- TIME-ORIENTED (give yourself enough time to meet the goal)
- You also want to use the FITT principle to design your workouts; for cardiorespiratory fitness
- Measure your FREQUENCY; this should be ~3-5 days per week for cardio
- Measure your INTENSITY, such as via measuring your heartrate (should be ~64%-96% of your maximum heartrate), V02 (volume of oxygen in your blood), or RPEs (ratings of perceived exertion)
- Your TIME should be ~20-30 minutes per day, in one long bout or multiple shorter bouts
- The TYPE should be rythmic, continuous movements of large muscle groups that's sustained for at least 20 minutes
- For muscular stength/endurance, you should also use the FITT
- For muscle gains, the frequency should be 2-3 days per week (or 1 day for maintenace); you should allow 2 days for recovery
- Intensity should be at least 8-12 reps (more, lighter reps for endurance training)
- Time should be <60 minutes
- For the TYPE, you should decide what muscles you want to work out and vary which ones you hit
- HYPERTROPHY is when your muscle cells increase in size, while HYPERPLASIA is when your number of actual muscle cells increases
- Hypertrophy is where most of these gains come from
- A total exercise program involves warm-up stretches, endurance training, then resistance training, then a cool-down/stretching period ("this is CRUCIAL for avoiding injuries")
- FUNCTIONAL TRAINING is when you try to improve specific, everyday tasks you want to do
- To exercise, though, you need fuel from nutrients, and there are 3 big nutrients you need
- CARBOHYDRATES are stored as glycogen in the muscles/liver; it's converted to glucose to generate ATP, and it's the primary substrate your body uses up during exercise
- FATS are stored in large amounts in the body; they have a high ATP yield (2x that of carbs), but are released more slowly (usually during prolonged exercise)
- PROTEINS shouldn't be the primary substrates during exercise, and are used up last
- You should eat ~20-25 grams of protein for muscle growth, and ~20g every few hours for protein synthesis (which increases after resistance training)
- Besides these, you also need fluids to let your body make sweat and cool you down
- You also NEED electrolytes after a workout (especially sodium and chloride)
- ...although you do lose some potassium as well
- In general, you should drink ~5-7ml of liquid for every kilogram of body weight 4 hours before your workout, and you should replace however much body weight you lost with water
- Don't drink TOO much water, though, as that can result in hyponutremia (i.e. water poisoning, too diluted)
- You should wait 3-4 hours after a large meal to exercise so your body can finish digesting your food for energy
- For meals, you should be eating carbohydrates and proteins, and avoiding fatty foods
- You should have ~3:1 ratio of carbs to proteins for "exercise fuel"
- AFTER exercising, though, you should eat something small ~30-45 minutes afterwards, and eat a full meal within 2 hours
- In general, you should eat more proteins and less carbs/fats to lose weight
- Another important thing: SLEEP!
- If you don't sleep enough, you'll be craving more sugar and fats, and less than 5 hours of sleep per night can be really harmful to your health
- Genetics/gender is huge (men put on muscle easier), experience knowing how to exercise, high stress/cortisol levels will break down muscle, etc.
- We should also talk about injuries while exercising
- There's 2 big types: OVERUSE injuries (gradually tearing your muscles due to repeated use), and TRAUMATIC injuries (torn all at once due to an accident, e.g. breaking a bone)
- The most common overuse injuries are "runner's knee," plantar fasciities, and shin splits
- To prevent these, wearing proper footwear/clothes, and using equipment properly, is important
- To treat an injury, remember RICE: Rest, Ice, Compression, Elevation
- Some special things to know about when exercising in extreme conditions
- In hot climates, watch out for HEAT CRAMPS (involuntary muscle contractions resulting from not enough fluids/electrolytes) and HEAT EXHAUSTION (blood pooling in extremities away from your brain, making you feel nauseous; this can develop into life-threatening HEATSTROKE, where the body's cooling mechanisms fail and can cause brain damage and bright red skin)
- In cold climates, you can have HYPOTHERMIA when the body cools down below 95 degrees (and below 90, your body's heating mechanisms like shivering start shutting down)
- Wearing proper clothing and starting off with light exercise in new environments is important
- Right now, 18-25, you're at your peak bone mass; as you age, your risk of fracture increases, so you should be increasing your BONE MINERAL DENSITY (BMD) by doing weight/resistance training and getting Vitamin D and calcium in your diet
- Also, avoid OVERTRAINING, where training too much can actually result in lowered hormones, higher levels of stress, and a weaker immune system from increased cytokines
- This is especially important before competitions, so Olympic athletes will often rest and move to light workouts anywhere from 4 to 28 days before major competitions