Feeling exhausted after a session isn't the same as receiving a well-directed training stimulus. My job as a coach is to organise the work so each exercise has a purpose, and progress can be assessed rather than guessed.
CORE IDEA
Mechanotransduction is the process through which cells convert mechanical information into biochemical signalling.
01
What is mechanotransduction?
When muscles produce force, their fibres experience tension and deformation. Force-sensitive structures — including integrin-associated complexes, elements of the cytoskeleton, costameres and mechanosensitive ion channels — can detect aspects of that loading.
This is the beginning of mechanotransduction: physical loading is translated into a network of intracellular signals that can influence protein turnover, structural remodelling and the muscle's capacity to adapt to future demands.
Load
The muscle produces force against resistance.
Sense
Mechanosensitive structures detect tension and deformation.
Signal
Biochemical pathways respond to the mechanical input.
Remodel
Repeated exposure supports long-term adaptation.
02
Mechanical tension is a stimulus — not a programming strategy
Mechanical signals are considered prime candidates for initiating hypertrophy-related responses. But simply adding more weight does not guarantee that the target tissue receives a better stimulus. Load must be expressed through an exercise, a range of motion, a level of effort and an execution strategy that fit the person and the intended adaptation.
“Hard” is not a sufficient description of good training. The stimulus must be purposeful, repeatable and recoverable.
A movement can be demanding while distributing force away from the muscle we intend to train. Conversely, a well-selected exercise performed with controlled execution may create a strong local stimulus without requiring maximal loads or maximal exhaustion.
03
From mechanical input to cellular signalling
Mechanical loading influences several interconnected signalling networks. These include pathways associated with mTOR complex 1 (mTORC1), a central regulator of translation and muscle protein synthesis, alongside other processes involved in cytoskeletal organisation, gene expression, autophagy and tissue remodelling.
IMPORTANT DISTINCTION
mTORC1 activation is not a guarantee of hypertrophy.
An acute rise in signalling after one session does not prove that a particular workout will create more long-term muscle growth. Signalling is part of the response; hypertrophy is the accumulated outcome of repeated training, nutrition, recovery and individual adaptation.
04
Protein synthesis, remodelling and hypertrophy
Resistance exercise can increase muscle protein synthesis, but not all newly synthesised protein immediately contributes to new contractile tissue. Especially during early training, some of that response may support repair and remodelling following unfamiliar exercise.
True hypertrophy is a long-term adaptation. It develops when effective training exposures are repeated and progressively organised while energy intake, protein intake, sleep and recovery support the process.
Muscle damage
Damage can occur, but more soreness or disruption does not necessarily mean more growth. Excessive damage may reduce the quality of subsequent training.
Exhaustion
Finishing depleted does not confirm that the intended muscle received a precise, recoverable stimulus.
Acute signalling
A short-term molecular response is not the same outcome as measurable hypertrophy over time.
05
What does the science change in practice?
I don't select movements simply because they look difficult. I select them according to the target muscle, intended adaptation, the client's current capacity and the amount of quality work they can recover from.
Consider a strict pull-up and a lat pulldown. Pull-ups can be valuable for developing the specific skill and strength of the movement. A pulldown can add back and elbow-flexor volume while allowing more precise control of load and fatigue. Neither exercise is automatically “better”. The right choice depends on the objective and the athlete in front of me.
What structured coaching monitors
- 01Exercise selection
The movement must match the target, the person and the phase.
- 02Execution and range of motion
Technique determines how the load is expressed and where the work is directed.
- 03Load, repetitions and assistance
Performance is recorded so progression can be measured rather than assumed.
- 04Effort and proximity to failure
RIR is managed according to the exercise, set, goal and current fatigue.
- 05Volume, frequency and recovery
The useful dose is the one that can be repeated and progressed.
- 06Nutrition and time
Adaptation requires sufficient resources and consistent exposure across weeks and months.
THE COACHING STANDARD
The objective isn't to maximise the difficulty of every set.
It is to organise effective stimuli that can be repeated, measured and progressed.
06
Scientific references
- Wackerhage H, Schoenfeld BJ, Hamilton DL, Lehti M, Hulmi JJ. Stimuli and sensors that initiate skeletal muscle hypertrophy following resistance exercise. Journal of Applied Physiology. 2019;126(1):30–43. View source ↗
- Schoenfeld BJ. The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research. 2010;24(10):2857–2872. View source ↗
- Damas F, Libardi CA, Ugrinowitsch C. The development of skeletal muscle hypertrophy through resistance training: the role of muscle damage and muscle protein synthesis. European Journal of Applied Physiology. 2018;118:485–500. View source ↗
This article is educational and explains the reasoning behind the Coach Leo Training System. Individual programming still depends on assessment, training history, goals and response.