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Principles of Exercise

Today’s blog is going to generally outline the different principles of exercise and how to incorporate them into your strengthening routine. These principles hold true regardless of your experience, strength, goals, and any other factor when it comes to exercising and are therefore important to understand. Everyone can apply them! However, when it comes to applying them, it’s of paramount importance to keep in mind training is highly individualized between each person. This brings us to our first principle:

1. Specificity: The SAID Principle

SAID stands for “Specific adaptations to imposed demands”, which means that our bodies will adapt to what we demand of them at the molecular level. For example, if you perform bicep curls all day you will end up with very large, overdeveloped biceps while continuing to have skinny legs. This is why it is so important to know what you are training for so that you are able to incorporate the proper exercises to achieve your goals or needs.

2. Variability

Let’s say you are training for a 10K and you establish a running program. If you consider the specificity principle, it seems like you would just have to keep running the 10K distance and then you would be golden, right? Not True! Your body will adapt to running that distance, but you will plateau with the gains you make pretty quickly as the body adapts to it. Just like the previous example of the person with the big overdeveloped biceps, you are risking overtraining and injury by imposing the same forces on the same parts of the body. If you varied your training with some resistance training or interval running, you would be using different muscles and the muscles that are used across all training sessions will be tested in different ways.

As an example, your stride will change and the muscle coordination will be slightly different when you jog slowly vs run faster during the interval runs. Therefore, variability reduces injury risk, allows you to continue improving and avoid plateauing with training, and makes it much more fun and interesting to maintain!

3. Overload

Remember, the body adapts to what it experiences, so if you want to improve any aspect of your fitness, you’re going to have to overload the structures of the body. This doesn’t mean going 100% from the start, but means doing something slightly more intense than what the body is used to.

For example, if you have never done any exercise in your life, you still have a baseline level of fitness from whatever you do during your daily life. Your body is used to the various squats and lifting you do when commuting, packing lunch, doing laundry, or whatever the daily routine consists of. This is why so many people gained weight and lost strength throughout the various stages of the pandemic. If they went from taking 6,000 steps a day commuting and walking around the office to 1,000 steps a day commuting from the bedroom to the kitchen to the home office, the body will adapt.

The opposite is true as a result, because when people went back to commuting or started performing additional exercise, they would notice it getting easier as their bodies adapted.

4. Progression: FITT principle

Even if you incorporate specificity, variability, and overload into your training, you would eventually plateau without progression of any component of FITT: Frequency, Intensity, Time, and Type.

Frequency: Generally performing exercise 1-2 times a week will allow you maintain your current level of fitness. It varies for aerobic vs anaerobic exercise, but you generally shoot for 3+ sessions each week to make exercise gains

Intensity: There are a few factors that play a role in intensity, and that is the volume of exercise, the load of the exercise, and amount of rest in between each set. These three factors dictate intensity and will vary depending on what your goal for exercising is. I will elaborate on these components in a later post since the information requires more detail than what you will find in this post. Generally, volume is the number of repetitions and sets of each exercise and the total number of exercises in the workout. Load is the amount of resistance you are working against measured by your 1 rep max, which is the maximum resistance you can work against with proper form. Rest can vary from just a few seconds (aerobic exercise) to 5 minutes (power and strength training).

Time: Simply the duration of the workout.

Type: There are many types of workouts that influence the effects on the body. Some examples include power resistance training, strength resistance training, muscular endurance resistance training, agility training, plyometric training, sprint training, aerobic threshold training, and aerobic endurance training to name a few. There is no inherent value to these different types of training; not one type of training is better than the other, but mixing and expanding the type of exercise in your training regime can result in progression. You can learn more about these different types of training in future blog posts.

As you can imagine, progressing any of these FITT components in your training regime will result in exercise progression and increased exercise gains.

5. Recovery

I personally believe this is the most important exercise principle because it will make the difference between someone optimally training or overtraining. Overtraining is a complex phenomenon and will be reviewed in a future blog post, however the general ideal is simple: overtraining can lead to injury. When I work as a physical therapist, this is where I spend most of my time counseling patients because oftentimes they did not recover properly which resulted in an injury. This can not be overstated: recovery is just as important as the exercise you do! You can have the perfect training routine for your goals, but if you don’t incorporate enough time to rest, your body will eventually break down: decreased performance -> fatigue -> injury. Sleep, relative rest, and proper nutrition ensure adequate recovery. Many exercise apps and watches can track the intensity of your workouts and effectiveness of your recovery to help optimize recovery and performance! I use the Coros pace 2 watch and the Whoop to track both metrics.

6. Reversibility

Unfortunately, this last principle of exercise is all too true as exercise gains made are completely reversible and can be lost much more quickly than they were developed. In patients that have their joints immobilized such as the right lower extremity after being put in a boot following a complex fracture, muscle atrophy can occur in as quickly as 1-4 days with severe atrophy occurring in 2 weeks. Typically cardiovascular endurance is lost more quickly beginning at about 2 weeks of inactivity than muscle bulk, which can be lost over the span of months.

This is very important to consider because it emphasizes the importance of consistency and ensuring training plans are not too rigorous and cause fatigue/overtraining that would lead to decreased adherence to an exercise program or cause injury.

This is also very important because if you went on vacation, got sick, and ended up going back to working out at the same intensity, chances are you will experience a setback including even an injury. I’ve made this mistake before and I see it happen all the time with my patients in PT.

7. Periodization

Periodization is the concept of modifying training specificity and load throughout a certain period of time and is broken down into cycles. Long story short, there are microcycles (1-2 week training periods), which make up mesocycles (2-6 weeks), which make up a macro cycle (several months to a year). This is done to optimize the principles of recovery and progression to allow athletes to “peak” in terms of performance throughout different times of the year.

For example, if you think of a professional football player, they clearly would break down very quickly performing such a physical sport competitively throughout the year. A macrocylce for that athlete would consist of a preparatory phase (preseason), a competitive phase (regular season and maybe playoffs), and a transition phase (offseason). The mesocycles will focus on different types of training to make sure athletes build their ability throughout the preseason to peak during the regular season and properly recover during the offseason without too much reversibility occurring while maintaining proper recovery to avoid overtraining/injury.

Concluding Thoughts

I hope you guys found this information helpful and interesting! I think it makes exercising much more enjoyable when you know the "why" behind what you’re doing. It also feels very rewarding when you know that you’re incorporating great strategies into your workout routine. The results are the icing on the cake.

Please let me know if you guys have any questions and ideas for future posts! I plan to go into more detail in the next few posts with certain topics covered today so it’s easier to incorporate these ideas into your daily routine. Thank you for your time!

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