Fitness Knowledge

Kip Landergren

(Updated: )

Contents

Overview

Fitness is physical competency.

It is the ability to

  1. move your body as you intend and
  2. to perform that movement efficiently, accurately, and without degradation for the entire duration it takes to accomplish

Training for fitness is the process by which you leverage your body as a mechanical—yet still fundamentally biological—system to produce adaptations changes necessary to reach your goals.

The process is a very sensitive feedback loop and one very gratifying to pursue!

Core Idea

Stimulus during exercise results in adaptation during recovery.

Careful, deliberate shaping of stimulus and management of recovery results in increased fitness.

Key Concepts

Specific Adaptation to Imposed Demand (SAID) Principle

The adaptation is going to be a reflection of the demand imposed.

Henneman’s Size Principle

Motor units (neurons + associated muscle fibers) are recruited in a fixed order based on motor neuron size:

as net excitatory input to the motor neuron pool increases.

Net excitatory input is the sum of inputs from:

It isn’t enough to just think “REALLY LIFT THIS WEIGHT HARD”, you actually have to have a force on the system sufficient to reach the excited state.

Interesting note:

The size activation has to do with the biological application of Ohm’s law where the smaller cross section of the membrane results in higher resistance, meaning less current is required to produce a given voltage change.

Training for Fitness

Training can be thought of as the management of:

to accomplish a desired level of fitness.

Some adaptations from exercise include:
skill the ability to coordinate movement efficiently and accurately
speed the ability to move at maximal velocity
strength the maximal force you can produce
power the rate of force production (force * velocity)
hypertrophy an increase in muscle fiber size
muscular endurance the ability of a local muscle to sustain repeated contractions
anaerobic power high-intensity work primarily without oxygen (~30 seconds to ~2 minutes)
VO2 max maximal aerobic power; highest rate of oxygen utilization (~3 to ~12 minutes)
long duration endurance the ability to sustain submaximal work for extended periods (30+ minutes)

Certain adaptations can positively interfere with each other while others compete.

Each adaptation requires a specific stimulus to develop. That stimulus is controlled through modifiable variables.

Some modifiable variables for shaping stimulus (and the subsequent adaptation) are:
exercise choice the movement pattern and muscle groups being trained
intensity relative effort (e.g. %1RM, velocity, or %max heart rate)
volume total work performed (often simply: sets * reps * load or duration)
rest intervals the time between efforts, influencing recovery and energy system contribution
progression the systematic increase or variation of stimulus over time
frequency how often training is performed

Developing a training program involves:

Galpin’s Laws of Strength

Three laws:

  1. progressive overload
  2. types of exercises do not determine adaptations; application determines adaptations
  3. strive for all joints through all range of motion

Progressive Overload

Progressive overload is a tool to shape the stimulus the body adapts to. It is the gradual increasing of demands—weight, volume, duration, and others—on the system beyond the stimulus threshold necessary for adaptation.

It is intentional in the way that:

This adaptation occurs in response to sufficient physiological stress.

Types of physiological stress include:
mechanical tension placed on tissues (e.g. force and stretch under load)
cardiovascular strain on the heart and circulatory system (e.g. heart rate, blood flow demands)
metabolic accumulation of byproducts from energy turnover (e.g. lactate, ions)
neural demands on the nervous system (e.g. motor unit recruitment and firing rates)

How should one think about what level of stress is “sufficient” to create an adaptation?

This can be estimated using lagging indicators (e.g. performance trends, fatigue, soreness), but is best understood as falling into one of four categories:
below threshold stress does not drive further adaptation
at threshold triggers adaptation, but slowly
above threshold maximal adaptation with minimized recovery time
too much major fatigue and risk of injury increases

Progressive overload provides a safe, tunable mechanism to generate stress approaching and then within the “above threshold” category.

The increased demand for progressive overload is tuned by manipulating the modifiable training variables.

Some example manipulations include:
exercise choice increasing coordination or stability demands (e.g. machines to free weights)
intensity increasing load or effort (e.g. 50% 1RM to 85% 1RM)
volume increasing total work (e.g. more sets, more reps, or more load)
rest intervals adjusting recovery to alter performance or energy system stress
frequency increasing how often a stimulus is applied through training

The progressive overload of these variables during training should be:

Exercise Choice, Application, and Adaptation

An exercise is an activity that gets you into the movement pattern you want to train. This movement pattern is often emphasized as being important to execute with good form.

Good form is a bit of a loaded term though, as it really captures two criteria:

For example:

It is possible to perform a chin up that looks correct but does not adequately engage the lats. Striving for good form means that the intended muscle groups are the dominant contributors to its execution.

Starting out with simple movement exercises:

Progressing to a technically difficult or complex movement becomes beneficial when you have the strength, skill, experience, and coaching to match.

The chosen movement pattern is itself not sufficient to determine adaptation: it must be combined with the actual application of effort. This application, chosen by adjusting the modifiable variables, shapes the stimulus the body experiences and thereby drives the adaptation.

Thus exercise choice does not determine adaptation, it is the application that determines adaptation.

All Joints Through All Range of Motion

A joint is the connection of two or more bones through a series of muscles and connective tissues that allows the exertion of force on the surrounding environment.

All joints have a safe operating distance governed by the nervous system. The nervous system has taken all that the joint has experienced—the bends, lifts, and injuries—up to now and determined a safe operating distance that joint can traverse.

To maintain this distance it sends control signals to muscles to relax or tighten depending on where the joint is in its range of motion. When you feel some limitation in the distance you are able to stretch this is due to the nervous system tensing the muscle to keep it within a safe range.

It is not that your tendons are “too tight”. It is not that your fascia is too stiff (stiffness does occur as a result of exercise, but not sufficient to wholly limit the range of motion of a joint). It is predominately a mechanism of the neural system firing to keep tissue from entering a perceived danger zone.

Training a joint through its current range of motion—especially at the limits—teaches the nervous system that it is safe to perform the movement. It develops, and then “learns” that it has strength at these bounds to control the position of tissue and not put itself into injury. This safe range of motion can increase as fitness increases because the nervous system accumulates data on what is actually safe. Intentional stimulus to this process—like through stretching and strength training—can cause adaptations where the body is able to perform normal movements with greater control and exceptional movements with lower risk of injury.

Thus a level of general fitness to strive for is to have strength through all the movements of the body, through all of its ranges of motion.

Downregulating Nervous System After Workout

Exercise elevates the nervous system state, adrenaline response, and other physiological processes.

Taking:

after a workout will:

Hypertrophy

Hypertrophy is the increase in muscle fiber size. Generally, everyone benefits from hypertrophy training.

Stimulus that results in hypertrophy adaptation involves:

The most reliable progressive overload variable for hypertrophy is approaching failure during the effort.

This will:

The measurement of “approaching failure” is to estimate what would be considered the number of reps in reserve (RIR) you have left when stopping. Hypertrophy stimulus is significant when an effort is done with 1-3 RIR.

A simple way to accomplish 1-3 RIR:

The top contour of a hypertrophy-based workout plan:

Approaching failure during a set does not mean the set was done with high intensity. Intensity is measured relative to your one-rep maximum (1RM), and, generally, 75%+ 1RM is considered a high intensity effort. A hypertrophy-based exercise done with 40% 1RM, between 8 and 30 reps, 1-3 RIR, is not considered “high intensity” despite the fact you really have to work for those last reps!

During the effort, keep the following in mind:

Evaluation for efficacy:

  1. did you feel muscle contract?
  2. did you get a pump?
  3. did you feel sore (but not destroyed) the next day?

The following variables are associated with hypertrophy:

positive association neutral or negative association
nearing failure intensity
volume
larger range of motion
recovery

Strength

Strength is the ability to maximally apply force to a movement.

It requires a combination of increasing:

  1. nervous system signal
  2. muscular contraction strength
  3. connective tissue force transfer

to improve.

The most reliable progressive overload variable for improving strength is intensity. This will stress the nervous system to recruit the maximal amount of motor units, contract them at maximum force, and transfer those forces via fascia and tendons.

Intensity is measured relative to your one-rep maximum (1RM), and, generally, 75%+ 1RM is considered a high intensity effort.

The top contour of a strength-based workout plan:

Minimal “3-5” strength plan (also applicable to power):

Intensity doesn’t always have to be maximal. Alternate example of an exercise’s effort:

set reps intensity
1 10 50% 1RM
2 8 60% 1RM
3 8 70% 1RM
4 5 75% 1RM

The following variables are associated with strength:

positive association neutral or negative association
intensity volume
rest
larger range of motion
frequency

Endurance

Endurance is 30+ minutes sustained effort of an activity.

Start with a concentric movements:

Be wary of movements with lots of eccentric lading:

as these are extremely high forces performed with high repetition, greatly increasing risk of injury. Knee, back, shoulder, and even neck pain result from movement compensation to handle these high loads. Which means you need the tissue development to support the effort.

Avoid pushing to fatigue during an endurance-based activity. The combination of loading and repetition in a fatigue state maximally increases risk of injury.

The top contour of an endurance-based workout plan:

Daily frequency is fine. Can safely combine with strength or hypertrophy training. Interference effect on limiting strength gains is overblown. Max heart rate tends to be complimentary with strength and hypertrophy.

Note: muscular endurance from planks and wall sits have carry over effects of improving posture (spinal muscles) and body movement (shoulders, etc) throughout day, reducing risk of injury.

The following variables are associated with endurance:

positive association neutral or negative association
volume

Speed

positive association neutral or negative association
higher frequency intensity
rep range
volume

Power

Power is velocity times strength. It benefits from speed and strength work.

The top contour of a power-based workout plan:

Minimal “3-5” power plan (also applicable to strength):

The following variables are associated with power:

positive association neutral or negative association
whole body movement single joint isolation

Cardiovascular

If you cannot willfully exercise to the correct heart rate, do not even do the exercise as you will get none of the benefit.

Tools

How to Activate a Reluctant Muscle

Cuing

Have a partner physically tap the muscle that you wish to engage.

Visualization

Look at the muscle (at the mirror flexing, or during the exercise) and focus your attention solely on contracting that muscle.

Eccentric Movement

An eccentric is the phase of movement where a muscle produces force while lengthening under load.

In many exercises, this is the lowering portion of the rep.

Examples:

Some training methods emphasize the eccentric by slowing it down or performing eccentric-only reps.

Because muscles can usually handle greater loads eccentrically than concentrically, eccentric-focused training can be useful for strength and hypertrophy (as long as control is maintained).

Isometrics

An isometric exercise is one where a fixed-length position is held for some duration, possibly under load.

By holding a fixed-length position the muscle must maintain a strong contractive force to both:

This benefits:

Additionally, the lack of repeated muscle contractions prevents regular flushing of metabolic byproduct leading to “the burn” sensation and further adaptation signaling.

Isometrics are especially beneficial for increasing range of motion (i.e. what would otherwise be considered improved by stretching) as they strengthen at the limits of the current range, conditioning the nervous system that future movements will be safe.

How to Manage Recovery

Improving fitness involves managing total stress vs. your recovery capacity.

Any time the total stress load outpaces recovery capacity, you're either going backwards in your physical ability or you're reducing adaptability.

Either reduce stress intake or increase recovery capacity.

On Muscle Tissue Recovery
tension dominant (e.g. isometrics) ~24 hours
metabolic dominant (e.g. endurance) ~24-72 hours
damage dominant (e.g. loaded eccentrics) ~48-72 hours

On Connective Tissue Recovery
anabolic signal responses (e.g. isometrics) ~24 hours
catabolic signal responses (e.g. plyometrics) ~48-72 hours

On Stiffness

Three kinds:

Connective tissue mechanical stiffness is generally not the main cause of range of motion limitation or general stiffness. Movement of this tissue helps flush fluids and keep it pliable.

The nervous system needs to be confident it can safely move the associated joint through its range of motion. It outputs a default “be safe!” contraction tone that causes the muscle to tighten when it begins to reach an unsafe range. That range is determined by your entire life’s worth of motor + sensation signals (including pain from minor and major injury!).

After a workout the nervous system has experienced a stimulus—lots of sensation—that causes it to raise the level of its default “be safe!” tone. Luckily, this is relatively easy to override relative to your normal range of motion. Movement the day after a hard workout teaches the nervous system “hey, this wasn’t an injury, this is still safe!”.

The limits of your range of motion, however, are stricter bounds as these are largely determined by an entire life’s worth of movement. The nervous system wants to have confidence that it has strength at the limits of its range of motion to ensure that it is not putting the joint or tissue into an injury position. This stiffness needs to be addressed with a targeted range of motion program (stretching + strength training).

On Soreness

Soreness is not a great indicator of workout efficacy. The pain we associate with severe soreness is from swelling and pressure resulting from calcium disruption during exertion—things that are not contributing directly to adaptation compared to say the microtrauma of muscle fibers. It is a useful signal to understand the demand placed on the body during the exertion but striving for soreness should not be a goal. Soreness is best used as an indicator for whether you overdid things during your prior workout. Recovery is critical to adaptation and time lost to soreness takes away from long term adaptation progress.

On Nervous System Fatigue

To gauge nervous system fatigue we need physical efforts that are:

These include:

Testing any of these in the morning after a workout will give insight into your nervous system state. Any significant deviation lower indicates your nervous system got sufficient stimulus during the workout.

Squeezing your hand into a fist is especially convenient because when done every morning upon wake up you will quickly develop the ability to distinguish the sensation of “muscle weakness” vs. “nervous system activation weakness”.

I find it hard to describe in words but muscle weakness feels like:

“I want to squeeze harder but am missing strength”

and nervous system feels like:

“I am squeezing harder but the force still doesn’t change”.

On Heat

Heat (e.g. hot bath) can:

On Cold

Cold immersion (more pronounced effect with moving water to remove the thermal envelop) can:

but a cold shower doesn’t cut it.

On Supplements

Talk to a professional.

Top 3, according to Galpin:

Breathing During Exercise

Brace and breathe, if you can, throughout the entire exercise.

Don’t worry too much about like “deep breath in on eccentric” or “exhalation on contraction”. If you have the core strength to brace and breathe continuously: do so.

Breathing is about one of two things:

Have a breathing strategy for rest periods:

Some breathing methods:
2:1 exhale:inhale
box breathing 1:1:1:1 inhale:hold:exhale:hold

How to Workout During Injury

Talk to a professional.

Assuming this is a minor injury where you feel pain during a movement: back off effort all the way down to just below that threshold of that's what aggravates the issue and train there.

This does two things:

Hydrating Properly

Rough daily guide: half your weight in lbs in ounces. e.g. 200 lbs targets 100 oz.

Consider:

People fall into one of two groups:

Easy test to determine: does your hat or clothing develop white bands after sweating? If yes, you are likely a high salt sweater and should consider consuming slightly more salt in your diet. Otherwise no change advised.

If you are losing more than 1% of your bodyweight during the endurance exercise: carry water with you.

Improving Proprioceptive Feedback

Fitness Terminology

Heart Rate Variability (HRV)
fatigue metric
High Intensity Training (HIT)
training to failure 6x month in very short intervals, popularized by Mike Mentzer
Specific Adaptation to Imposed Demand (SAID) principle
the result of your training is a reflection of the demand you imposed
brace
(maintain intramuscular, intra-abdominal pressure)
compressive loading
when a tendon experiences compressive force from joint movement while undergoing strain load (e.g. the upper hamstring tendon is compressed by pelvis when lowering to squat)
eccentric exercise
the elongation of a muscle under load. some eccentric exercises are when the force applied to the muscle/tendon system just exceeds its maximal contractive force and there is a forced—but still controlled—lengthening (e.g. negative chin ups)
gene cascade
chain of gene activations where each step controls the next, shaping how cells develop, specialize, and function over time. (how the piano was built and tuned in the first place)
hypertrophy
(muscle fiber) size increase
motor neurons
upper and lower
multi joint movement
e.g. full snatch
neural signals
real-time control (like pressing keys on a piano)
pennation angle
angle of which muscle fibers lay relative to the bone
prime muscle
the primary muscle used in a movement
progressive overload
the process of gradually increasing demands—weight, volume, duration, and others—on the system beyond the stimulus threshold necessary for adaptation
proprioceptive feedback
the signals from sensory inputs back into the nervous system to generate knowledge of where the limbs are
pull exercise
moving weight perpendicularly toward the body
push exercise
moving weight perpendicularly away from body
single joint movement
e.g. bicep curl
supersetting / supersets / super sets
working alternative muscle groups during rest inervals
synergistic muscle
secondary or tertiary muscle used in a movement
working set
a set of exercises that is not warm up and in a specific range of difficulty that you are intentionally trying to achieve

Sources