This week we hit the Instagram trough to see what stuff in the fitness and nutrition space you just don’t understand, so here we are… our first ever “explain it like I’m 5”. 

TOPIC 1: LINDSAY ASKED ABOUT RPE

RPE is “rate of perceived exertion.” Perceived exertion is how hard you feel like your body is working. It is based on the physical sensations a person experiences during physical activity, including increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue.

1. Let’s start with why you would want to use RPE scale instead of a percentage program. Even though percentage programs are easy to use, they can be limited in how accurate they are. There are maaaaany things that can throw off your percentages. 
   • The longer you go in a training cycle, the less accurate they become due to your individual strength adaptation.
2. The scale looks like this:
   • 10: Maximal, no reps left in the tank
   • 9: Last rep is tough but still one rep left in the tank
   • 8: Weight is too heavy to maintain fast bar speed but isn’t a struggle; 2–4 reps left
   • 7: Weight moves quickly when maximal force is applied to the weight; “speed weight”
   • 6: Light speed work; moves quickly with moderate force
   • 5: Most warm-up weights
   • 4: Recovery; usually 20 plus rep sets; not hard but intended to flush the muscle
   • We don’t talk about anything under a 4
3. Here’s how it works. You apply it to a set/rep range. 
   • For example, if you were going to do 5×5 at an 8–9 RPE, you know that you’re doing 5×5 with a weight that is between an eight RPE and a nine RPE. So you should select a weight that will allow you to do between one and four more reps than the set requires.
4. Here’s why people don’t use it as much as percentages: percentages are easier. RPE is great, but if you’re not an established lifter, it can be hard to implement, because how do you know what weight will allow you to do one to four more reps than the set requires? That takes a lot of time in the gym. 
   • RPE is a perfectly cromulent programming strategy, but it’s def not for everyone as it can be confusing.

TOPIC 2: LAURIE SAYS CALORIES IN, CALORIES OUT

“Calories in versus calories out” is based on the idea that to maintain a stable weight, the number of calories you eat needs to match the number you expend… and to lose weight, you need to eat less calories than you expend. Calories in is what you eat, calories out is what you burn.

1. There are 3 ways your body burns calories: metabolism, digestion, and physical activity. That’s it. No cleanses, no thermogenic bullshit, no wraps. Let’s dig in. 
   1. Metabolism – we’ve covered this before, but TL;DR – Your body uses most of the calories you get from food to sustain basic functions, when you hear people mention base metabolic rate or BMR, this is what they’re talking about. 
   2. Digestion – 10–15% of the calories you eat are used to power digestion. This is known as the thermic effect of food and varies based on the foods you eat.
   3. Physical activity – all of the leftover calories you get from your diet are meant to fuel your physical activity, including workouts and everyday stuff like walking and washing dishes.
2. Burn, baby, burn! From a biological perspective, you need to eat fewer calories than you burn to lose weight. There’s no way around it. It is a fact of life. 
   1. Once your body’s energy needs are met, extra calories are stored for future use… some goes to your muscles as glycogen, but most of it will be stored as fat. 
   2. Thus, eating more calories than you burn will cause you to gain weight, whereas eating fewer than you need will cause weight loss.
3. Now what about those people yellin’ about the type of food that matters? Not even gonna address it. We talked about it with Dr. Fit and Fabulous on episode 15. You can eat 1000 calories of lettuce or 1000 calories of French fries, your body doesn’t care what it is, it’s just gonna break the nutrients down and send them where they need to go. 
   1. Some diets can also affect water intake and cause muscle loss which can give the illusion that said diet is effective for fat loss. This is why protein intake during a weight loss phase is imperative. You don’t want to lose any muscle. 

TOPIC 3: J WANTS TO KNOW ABOUT CREATINE

Creatine is a naturally occurring substance in your body, and it’s the most-studied supplement. We can get real deep on this one, cuz there are stacks of info to swim through. 

1. What IS creatine though?
   • The dictionary definition is: a compound formed in protein metabolism and present in much living tissue. It is involved in the supply of energy for muscular contraction.
   • Creatine is a substance found naturally in muscle cells. It helps your muscles produce energy during heavy lifting or high intensity exercise.
   • What’s it do for us?
2. Chemically speaking, creatine shares many similarities with amino acids, important compounds in the body that help build protein. Your body can produce creatine from the amino acids glycine and arginine
   • About half of your body’s creatine stores come from the food you eat — especially red meat and seafood — and the rest is made in your liver and kidneys from amino acids
3. Why do people supplement it?
   • Taking creatine as a supplement is very popular among athletes and bodybuilders. They use it to gain muscle, enhance strength, and improve exercise performance
   • When you supplement, you increase your stores of phosphocreatine. This is a form of stored energy in the cells. It helps your body produce more of a high energy molecule called ATP.
   • ATP is often called the body’s energy currency. When you have more ATP, your body can perform better during exercise
4. Creatine also alters several cellular processes that lead to increased muscle mass, strength, and recovery
   • Boosted workload. It enables more total work or volume in a single training session, a key factor in long-term muscle growth
   • Improved cell signaling. It can increase satellite cell signaling, which aids muscle repair and new muscle growth
   • Raised anabolic hormones. Studies note a rise in hormones, such as IGF-1, after taking creatine
   • Increased cell hydration. Creatine lifts water content within your muscle cells, which causes a cell volumization effect that may play a role in muscle growth
   • Reduced protein breakdown. It may increase total muscle mass by reducing muscle breakdown
   • Lower myostatin levels. Elevated levels of the protein myostatin can slow or inhibit new muscle growth. Supplementing with creatine can reduce these levels, increasing growth potential 
5. Creatine supplements also increase phosphocreatine stores in your brain, which may promote brain health and improve symptoms of neurological disease
   • Creatine is one of the cheapest, most effective, and safest supplements you can take.It supports quality of life in older adults, brain health, and exercise performance. Vegetarians — who may not obtain enough creatine from their diet — and older adults may find supplementing particularly useful. Creatine monohydrate is likely the best form if you’re interested in trying creatine to see if it works for you.

https://www.cdc.gov/physicalactivity/basics/measuring/exertion.htm

https://www.elitefts.com/education/training/rate-of-perceived-exertion-rpe/

https://www.healthline.com/nutrition/calories-in-calories-out#what-it-is

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6315740/https://www.healthline.com/nutrition/what-is-creatine#other-benefits