1. "I worked out today, and after exercise your metabolism is raised....so I can eat whatever I want!"
Yeah...no. This one comes first and foremost because I hear people say this ALL the time. This is a surefire way to keep yourself from seeing the results of your hard work. I even fell victim to this flawed way of thinking when I first got into going to the gym right after high school. We would hit the gym for an hour, then head across the street to Carls Jr and demolish a combo meal. Then see no results (couple of my friends actually GAINED weight this way).
While yes, it is true that your metabolism stays slightly raised after exercise (your body is replenishing the glycogen and ATP stores in your muscles, repairing your muscles, and other things) the caloric difference it makes is not enough to warrant eating ALL THE THINGS! Not only that, but unfortunately most people vastly overestimate the amount of calories they burn while exercising, and underestimate the number of calories that they eat. That is an equation for gaining weight, and can be disheartening when starting an exercise program only to see yourself GAINING instead of losing weight.
The most important thing to focus on if your goal is fat loss or general fitness is the number of calories in versus the number of calories out. Since exercise tends to boost appetite plan them right before a meal, that way you don't overindulge, since you were going to eat the meal anyway. Keep track of how many calories you burned (this varies by your weight and exercise intensity level...so factor these in! A 200 lb person burns more calories during a 1 mile walk than a 150 lb person for example) and unless you are working out for over 1 consistent hour of endurance cardio stay away from sports drinks! They have as many calories as soda and serve no purpose during short workouts. Most importantly remember - YOU CANNOT OUT TRAIN YOUR DIET. If you are eating crap you might get away with being thin if you limit your calories, but you will not be fit!
2. "Muscle confusion" is the most effective way to quickly increase muscle size and strength and avoid exercise plateaus.
Oh man, this whole concept of "muscle confusion" is complete and utter BS, broscience to the max. P90x is to blame for tricking people into thinking this is actually a thing...alas, it is not. The claim is that switching your workout every few weeks or so "confuses" your muscles allows them to increase in size more than normal, and avoids the plateau effect (where your body adapts to an exercise and your fitness improvement decrease or level out).
As legit as that sounds...your muscles do not work that way. The ONLY way to increase muscle size and strength is through progressive overload (gradual increase of stress placed on the body during training). Switching up your workouts regularly is good for other reasons, like giving certain groups time to repair and things like that, but that alone wont grant a bigger increase in size/strength. You cannot "confuse" your muscles...either they are being overloaded or they aren't. The more fit you get, the more you will have to increase things like speed, intensity and weight to continue to progress. Taking a break from one exercise only to start again at the same level wont do much...it is all about increasing the load.
3. Protein is muscle food, eating it goes straight to muscles and it's okay to eat in any amount.
Yes, people who work out do require more protein than those who do not work out (for muscle repair, synthesis, etc) 0.5 to 0.8 g of protein per lb of body weight is recommended for those looking to increase lean body mass... but protein calories are still calories. Protein is not some magic macronutrient that you can eat unlimited amounts of and have no adverse effects. Protein, whether it be from protein powder, meat, tofu, or veggies...will still make you fat if you consume too much. Once your body has used all the protein it requires the leftover calories are treated just like every other food source - converted to fat and stored in your body for energy. The crazy thing is protein powders and drinks tend to have a LOT of calories, and I see people chugging them all the time thinking they're doing their muscles a favor. Be mindful that protein, and any other health food for that matter, still has calories and too much WILL make you fat.
4. Going below 1200 calories in a day, or going a day without food will put your body into "starvation mode" and then you will hold onto every calorie you consume. Meaning eating too LITTLE will cause weight GAIN.
The good old starvation mode fallacy...this is another common misconception I hear very often. This is also a form of "fat logic" (logic about nutrition/exercise that is incorrect and will get/keep you fat). I am tired of hearing overweight people say that they think they are overweight because they don't eat ENOUGH, and their body is in starvation mode. There is so much wrong with this assertion, and I'm here to break it down for you: Starvation mode is not real unless you are ACTUALLY starving, and your body fat is low enough that it's below the minimal amount needed to live on. Even then, fat cannot come from nowhere, your body cannot magically gain weight from calories it did not consume. The laws of thermodynamics do NOT work that way. You don't absorb calories and fat through thin air.
The starvation mode myth got popularized by a certain Minnesotan study that tracked men on a very calorie restricted diet. Toward the end of the study some of their metabolisms had slowed down by as much as 40%....and people latched onto that to mean that will happen to anyone if they skip a meal or eat too little calories one day. NO. Two important things to note: The 40% decrease in base metabolic rate was only noted toward the end of the study, when these men had been on a severely restricted calorie intake for MONTHS and their body fat level was at or close to the minimal functional amounts. Also, the men STILL LOST WEIGHT even with the 40% metabolic decrease, because they were still eating very low calories.
Eating less than your body uses in a day will cause weight loss, point blank. When people reach a plateau during weight loss you are NOT IN STARVATION MODE. The answer is not to eat more, it's to introduce a new challenge/ exercise for your body to adapt to. The starvation mode myth is one of the main things keeping people fat. I have seen countless people who say they think they're overweight from eating too little have their actual macros/calories counted only to find out they were consuming a lot more than they thought they were. If you are gaining weight I guarantee you, it is not because you aren't eating enough.
5. Spot reduction, aka losing fat in one area of your body.
Hate to break it to you, but spot reduction is a myth. No matter HOW many crunches or how much pilates you do you will NOT have a six pack (or visible abs at all) unless your OVERALL body fat percentage is low enough. It annoys me when I see these ads for workouts promising "Six pack in 2 weeks" to everyone, because that is just simply not the case. Your body cannot only burn fat from one particular area, because muscles don't get fueled by local fat. Fat supplies us with energy by being broken down and circulated through the bloodstream, then used as needed. That means that even though you are working a particular muscle the fat used to provide that energy is what is coming from the body as a whole, and reduction of body fat is pretty balanced everywhere in the body.
From wikipedia: "The misunderstanding may be attributed to the firming and shaping effect of muscle hypertrophy. When additional muscle is built, it takes up new space which can briefly compress subdermal fat against the skin until the skin adapts, a larger bulging muscle shape is also more easily seen through the layer of fat on top of it. This can give the illusion of fat being reduced when it has not." The only way to lose fat from your abs (and anywhere else on your body) is through a caloric deficit, aka burning more calories than you consume.
These are just a few of the myths that I hear consistently about fitness. The amount of broscience that is misguiding people looking to eat right and get more fit is absolutely ridiculous! When you want specific results from a workout, do your research and don't believe everything the first gymbro tells you. Hard bodies come from hard work...there is no shortcut.