Strength & Conditioning (SC) provides a detailed approach to improve fitness levels. From a biologic perspective, nature did an outstanding design bringing us to life. Among all that nature surprising beauty, the secrets beneath stunning life seem to have been precisely ordered for a purpose. SC applications aim to trigger responses and improvements to certain physiological levels using different pathways played by the rules, the genetic code. Therefore it seems an acceptable strategy that SC sets its targets on the very fundamentals of exercise physiology. In consequence no matter what orientation of the goal/s or the need/s have to be targeted, any exercise application per equal is based on the fundamentals of its true functional existence.
Despite field complexity, science success decoding how it works played a crucial role on understanding a large number of exercise physiology pathways and adaptations. To summarize physiological pathways and outcomes into the SC fitness spectrum, ATHL.Core framework is based in 5 main fitness attributes. Those 5 are:



Metabolism is the term which englobes the countless chemical process going down continuously on biologic organisms, in other words it is the energy management. Metabolism leads us into process that lay inside the realm of physiology and biochemestry. These processes allow life to be sustained including the regulation of all normal function related to it. Metabolic processes include 2 main frameworks:  (1) breakdown nutrients from food and (2) built and repair our body. As a matter of fact, it all relies on how energy is managed, used, converted and stored for use. The overall balance its called homeostasis which refers to the baseline for general normal function.

The complexity of metabolism includes an infinite network of relations, however two principles regulate this stunning operation of life:
+ Anabolism: Is the build up of compounds
– Catabolism: Is the breakdown of compounds due to its use and damage or the breakdown of compounds such as food which then will be used to provide energy or building the basic blocks for futher growth or repair.

Every day we spend energy. This energy is used to keep body systems on its daily normal function duty such as breathing, keeping the heart beating, blood flow, growing and repairing cells and adjusting hormone levels. How the baseline energy is spent is completely out of our reach, however exercise and phyiscal activity has the power to modulate and induce metabolism rates.


Basically when we talk about metabolism we end up talking about processes and energy, how much its spend, how much its needed, how it will supply the demand,… or any other possible combination of its inter-relation. Energy is measureable, the units are Kilojoules (KJ) or Kilocalories (Kcal). In both cases, despite unit different appraoches in the international system they reflect the amount of heat needed to raise the temperature of one kilogram of water by one degree Celsius.
Our energy expenditure can be measured, and directly relates to metabolic rates. Before we go deep into metabolism, exercise and phyiscal activity here is what you need to know about the energy balance and its components:

Energy balance: The simple principle of how much energy is used and how much energy is restored. In other words how much do you burn and how much fuel do store in the tank.
Total Energy Expenditure (TEE):
Its the sum of resting energy expenditure, thermic effect and physical activity expenditure.

Resting Energy Expenditure / Resting Metabolic Rate: It is the metabolic baseline for sustained life and normal function. Its value ranges from the 60-70% of TEE.
Thermic Effect: It is the energy related to breakdown food processing. Its value ranges from the ∼10% of TEE.
Physical Activity Expenditure: It is the energy spent in movement including daily activities (housekeeping, commuting, grocery shopping,…) and programmed exercise (play sport, physical recreational activities, resistante training, strength & conditioning programs..). Its value ranges from the 20-30% of TEE.

Resting Energy Expenditure (REE)

REE refers to the amount of energy your body needs to maintain homeostasis. Here are few factors that condition your Resting Energy Expenditure:

1. Age – Metabolism slows down with aging.
2. Growth – Children have higher energy demands due to growth and maintaing homoestasis.
3. Gender
4. Genetics predisposition
5. Illness or infection – In critical vital scenarios REE increses to fight against harmful agents.
6. Endocrine system – Hormonal imbalances can influence how quickly or slowly the body burns energy.
7. External substances – Ergogenic aids or drugs can alter REE
8. Temperature – Hot/Cold environements have thermoregulation stress effects to maintain homeostasis.
9. Body composition – Percentage of tissue distribution can benefit REE, such as muscle.
10. Physical activity

It is believed, that metabolic baseline is completely out of our reach, however this statetment is far from true. Meanwhile there are true sceneraiors where factors are unmodifialble as age, growth, gender, genetics and infections others do not stand on that unreachable status. There is one that has the potential to induce regulations, adaptations and benefits to others, that one is PHYSICAL ACTIVITY.


Physical activity and exercise are different concepts, meanwhile physical activity englobes all type of movement and sport practices, exercise is a task or an activity deliberately planned, structured and repetitive that seeks to improve or maintain an adaptation contributing to enhance fitness and health. To learn more about its differences, click here. Both expend energy and have an impact to metabolism and REE. However, to target something we need a goal and a dose of exercise to progress from point A to B. Exercise prescription within a Strength & Conditioning program is a precise tool to adjust the dose, tolerance and achieve benefits. Some beneficial impacts of exercise in metabolism are:

+ Exercise consumes energy. Muscle and life sustaining functions have to adapt to the needs of demand during exertion, increaseing your daily expenditure.
+ Exercise increases muscle activity and triggers muscle adaptations, these stimulous can lead to muscle growth changing body composition. REE is largely determined by your total lean mass.
+ Exercise and physical activity have a variety of intensity/energy demand thresholds, working at certain rates and intensities can modifiy body composition.
+ Muscle behaves as an endocrine organ does not only provide a platform for structural integrity and locomotion, it also influence, regulates and balances hormonal activity.
+ Exercise increases functionality and strength, reducing aging metabolism disfunctions.

Physical activity is a fundamental pilar for health and wellbeing. Increasing exercise, movement and daily activity has become one of the more important factors for maintaining life and its vital functions. Physical activity turns out to be the primary call to action for health and fighting sedentarism. Here are some sedentary behaviors, do you have any match?

! Long periods of daily inactivity.
! Less than 150 min of exercise/physical activity per week.
! No resistance training.
! Less than 10000 steps per day.




Energy production allows us the ability to be alive, move and interact with the world physically and cognitivly, once was exclusively for survival, today it might be a blend between survival and enjoyment.
Exercise metabolism is a dynamic continuum of the demand exerted by musculoskeletal system. Metabolism has a serious network and casade of effects draging with it all system to a certain extent. Special stress consideration rely into cardiovascular, digestive and endocrine systems.

Energy demand will always be intensity dependant, and how this energy needs to be supplied through different and adaptable energy pathways. As long as movement, resistance or muscle work persist additional demand to beforementioned Resting Energy Expenditure o REE will exist. Physiologically we developed efficent pathways to supply demand at rest and at exhertion. Once again the body itself does not differentiate energy requiriments for hunting, farming, surviving, swimming, running or climbing it simply procures to supply the needs to mantaint homeostasis within its capacities to perform whatever task is at demand.

There are to main energy source pathways: aerobic and anaerobic. Both, always dynamically coexist at demand requirements, anaerobic pathways are usually involving more close to maximal effort exhertions. The downside is anaerobic has an expensive toll in the energy dynamic continuum, pushing system functions to its maximal possibilities. Simultaniously, aerobic pathways have fundamental properties, and like anaerobic there are threshold limits, dinamism and efficency closely related to muscle type (muscle fibre types histology) and cardio-respiratory system physiology.

Metabolism profiling is a helpful knowledge tool to target individual exercise exposure triggering adaptations within muscleskeletal, endocrine, cardiovascular and respiratory systems. It provides a reliable platform, when individualized, to enhance exercise tolerance, optimize cell functions, improve thresholds and performance.




Metabolism is vital and a fundamental element within Strength and Conditioning for health and athletic development. The relationship between energy balance, total energy expenditure and resting energy expenditure are important factors to health and an efective approach to fight and reverse sendetarism behaviors and their nocive consequences. The complex network of metabolism and physical activity practice is a powerful tool to target energy consumption, body composition and muscle growth, muscle as endocrine organ and reverse aging disfunctions.
Metabolism profiling is an efficent and efective tool applied into exercise presciption for health and exercise prescription for training, targeting different energy pathways. Metabolism for health?, Metabolism for athletes?, metabolism goals are vital to maintain life on its balance on every individual being. Physical exercise within a Strength & Conditioning program provides an efective treatment to awake disfuntions due to sedentarism or health conditions meanwhile on the other hand provides efective stimulous to enhance homeostasis resilience increasing anaerobic and aerobic profile efficency with ultimate athletic performance.


Do you wanna learn more about Strength & Conditioning in different applications and how a program might fit your needs? Find our more about ATHL.Exercise and ATHL.Core framework goals in our blog, here:

All you need to know about fitness
Health-fitness and the 7 outcomes to look for
Injury prevention and REhab, 7 outcomes to look for
Strength & Conditioning for athletic development
Why balance is critical?
Why strength is essential?
Why metabolism is vital?
Why endurance is important?
Why recovery is noteworthy?




About the author:
Albert Piñol – Master of Physical Activity and Sports Science, MSc in Exercise Physiology, DHE Snowboard trainer, DH Mountain guide & Mountainbike and MAT certified. Snowboarder, exercise science and adventure sports enthusiast. IG: @albert_pinol