🔵 PLAYBOOK B — FUEL & TUNE THE ENGINE · Peptides: Out of the Shadows

🔵 PLAYBOOK B — FUEL & TUNE THE ENGINE

L-Carnitine + MOTS-c Metabolic Optimization

Once the mitochondrial assessment suggests that the mitochondrial machinery itself is functioning reasonably well, the objective changes from restoration to metabolic optimization.

This is where injectable L-Carnitine + MOTS-c come into the picture.

Playbook B is built around three components working together:

Fuel availability. Metabolic signaling. Muscular demand.

The sequence—and especially the timing—is an important part of the protocol.

⛽ L-CARNITINE — BUILDING THE FUEL-TRANSPORT FOUNDATION

L-carnitine plays an essential role in mitochondrial fat metabolism.

Long-chain fatty acids cannot simply pass through the inner mitochondrial membrane and enter the mitochondrial matrix. They rely on the carnitine shuttle, a transport system that allows those fatty acids to reach the mitochondrial matrix where beta-oxidation can break them down and ultimately contribute to ATP production.

In practical terms:

Fat can be available as fuel, but the mitochondrial machinery still needs a way to get that fuel inside.

That's where carnitine comes in.

But simply increasing L-carnitine in the bloodstream isn't the objective.

Skeletal muscle contains the vast majority of the body's carnitine, and that's where we want it available when exercise creates a substantial demand for energy. The challenge is that skeletal muscle takes up L-carnitine slowly and under tight regulation. Increasing circulating L-carnitine therefore doesn't immediately translate into a corresponding increase inside skeletal muscle.

At the same time, excess circulating L-carnitine is not stored or held in reserve waiting for skeletal muscle to use it later. What isn't taken up and retained by tissue is subject to renal clearance and elimination through the urine.

That creates the central challenge:

Muscle uptake is slow and regulated, while excess circulating L-carnitine can be cleared relatively quickly.

So, the objective isn't to create one enormous temporary increase in circulating L-carnitine immediately before exercise.

The objective is to repeatedly expose skeletal muscle to increased L-carnitine availability over time, progressively building and re-aligning the muscle carnitine pool toward a higher level of intramuscular availability.

That is why Playbook B doesn't begin by simply taking L-carnitine and MOTS-c together before the first workout.

We load L-carnitine first.

🔋 DAYS 1–15 — L-CARNITINE LOADING PHASE

The first 15 days are dedicated exclusively to establishing that L-carnitine foundation.

L-Carnitine: 300–500 mg IM daily MOTS-c is withheld during this phase.

The daily schedule exists for a reason.

We're working with a tissue that doesn't rapidly absorb L-carnitine. A single exposure can dramatically increase what's available in circulation without producing an equally rapid increase inside skeletal muscle. And whatever remains in excess isn't simply held in the bloodstream until the muscle eventually decides to take it up.

So, we repeatedly increase availability.

Day after day, for 15 days.

Each exposure presents skeletal muscle with another opportunity to take up and retain L-carnitine. Over the loading period, the objective is to progressively move the muscle away from its existing baseline and establish a larger intramuscular carnitine pool.

This is what we're accomplishing during the loading phase.

We're not trying to keep L-carnitine permanently elevated in the bloodstream.

We're not asking one pre-workout injection to build the muscle's carnitine stores immediately before exercise.

And we're not loading simply because “more is better.”

We're using repeated daily exposure to work with a slow, regulated skeletal-muscle uptake process and establish the larger muscle carnitine reservoir that the remainder of the protocol is designed to use and maintain.

That distinction becomes extremely important once the loading phase ends.

After Day 15, L-carnitine does not disappear from the protocol.

What changes is the frequency.

The daily loading phase has served its purpose: establish the intramuscular foundation. From this point forward, L-carnitine moves from daily loading to approximately 3–4 administrations per week, paired with resistance-training days.

The objective has changed from:

BUILD THE POOL → MAINTAIN AND USE THE POOL

That is also why the pre-workout L-carnitine administration during the active phase shouldn't be viewed as starting from zero every time we train.

We've already spent the loading phase establishing the foundation.

Now the continuing L-carnitine exposures are intended to support that foundation while positioning increased L-carnitine availability around the training window.

And this is where the second component of Playbook B finally enters.

MOTS-c.

The first phase established the fuel-transport foundation.

The next phase combines that foundation with metabolic signaling and muscular demand.

LOAD → ESTABLISH → MAINTAIN → SIGNAL → TRAIN

Now we're ready to put the system to work.

🧬 MOTS-c — THE METABOLIC SIGNAL

MOTS-c occupies a very different position in this combination.

It is a mitochondrial-derived peptide associated with cellular energy sensing and metabolic regulation, including signaling involving AMPK.

AMPK is essentially one of the cell's energy-management systems. When cellular energy demand increases, AMPK signaling helps shift metabolism toward processes that generate energy while reducing processes that consume energy unnecessarily.

That includes effects involving glucose utilization and fatty-acid metabolism.

So, L-carnitine and MOTS-c aren't doing the same job.

L-Carnitine supports the physical transport machinery required to move long-chain fatty acids into the mitochondrial matrix.

MOTS-c provides a metabolic signal associated with how the cell responds to energy demand and utilizes available fuel.

Then we introduce the third component:

Resistance training.

⚙️ WEEKS 3–12/16 — THE ACTIVE FUEL & TUNE PHASE

After completing the 15-day loading phase, daily L-carnitine administration stops.

From this point forward, both L-carnitine and MOTS-c are paired specifically with resistance-training days for the remainder of the 12–16-week protocol.

ACTIVE-PHASE TIMING

45 minutes before resistance training:

L-Carnitine — 400–600 mg IM

15 minutes before resistance training:

MOTS-c — 500–1000 mcg SubQ

0 minutes:

Begin resistance training

That means there is approximately 30 minutes between L-carnitine and MOTS-c, followed by another 15 minutes before resistance training begins.

And that timing isn't simply an organizational convenience.

It is part of the design of Playbook B.

⏱️ WHY THE 45 / 15 / TRAINING SEQUENCE MATTERS

Think about what we're trying to bring together during one training window.

T–45 MINUTES — L-CARNITINE

L-carnitine goes first.

Remember, we've already completed the 15-day loading phase. We're entering the active phase with the objective of having an established skeletal-muscle carnitine foundation.

The pre-workout IM administration is positioned ahead of training to increase L-carnitine availability as the exercise window approaches.

There is an important distinction here.

We're not claiming that an IM L-carnitine injection reaches a scientifically established blood peak at exactly 45 minutes or that the carnitine from that particular injection reaches the mitochondria exactly 45 minutes later.

Human pharmacokinetic research defining an exact IM peak and an injection-to-skeletal-muscle mitochondrial timeline is limited.

That's precisely why the loading phase matters.

We're not asking today's injection to build the entire system in 45 minutes.

The foundation has already been established.

T–15 MINUTES — MOTS-c

Thirty minutes after L-carnitine, MOTS-c is introduced.

Now we're adding the metabolic-signaling component closer to the training stimulus.

MOTS-c has been studied for its relationship with AMPK and cellular pathways involved in glucose and fatty-acid metabolism.

Here again, we need to distinguish the protocol from what has actually been established pharmacokinetically.

There isn't good human pharmacokinetic evidence demonstrating that a SubQ MOTS-c injection reaches a precise biological peak exactly 15 minutes later.

So, 15 minutes isn't being presented as a scientifically proven MOTS-c Tmax.

It's the timing window we're using to position the metabolic signal immediately ahead of the exercise stimulus.

T–0 — RESISTANCE TRAINING

Now the final component enters the picture.

Muscle contraction.

Once resistance training begins, working skeletal muscle rapidly increases its requirement for ATP.

The energy demand has changed.

The mitochondria inside those muscle cells now have to respond to the increased workload and generate the ATP necessary to support muscular contraction.

This is where the pieces of Playbook B come together.

Fatty acids are available.

The carnitine shuttle provides the machinery required to move long-chain fatty-acid groups across the inner mitochondrial membrane.

MOTS-c provides a metabolic signal associated with cellular energy management and fuel utilization.

Resistance training creates the actual energy demand.

Inside the mitochondrial matrix, those fatty acids can undergo beta-oxidation, ultimately contributing to

ATP production.

AVAILABILITY → SIGNAL → DEMAND → MITOCHONDRIAL ENERGY PRODUCTION

That is the logic behind the timing.

We're deliberately trying to place carnitine availability, MOTS-c signaling and muscular energy demand into the same exercise window.

🏋️ TRAINING DETERMINES THE ACTIVE-PHASE FREQUENCY

Once the loading phase is finished, the calendar no longer determines how frequently L-carnitine and MOTS-c are administered.

Your resistance-training schedule does.

If you resistance train 3 days that week, you have 3 active protocol days.

If you resistance train 4 days, you have 4 active protocol days.

The original protocol likewise reserved the active combination for resistance-training days rather than cardio or rest days.

No resistance training that day = no active-phase L-carnitine/MOTS-c administration.

The compounds aren't being used simply because another day has arrived.

They're being deliberately paired with the physiological event we're trying to exploit:

Working skeletal muscle creating a substantial demand for energy.

This training-day structure continues through the remainder of the 12–16-week protocol.

📊 TRACK THE FUEL & TUNE PHASE

Throughout the protocol, continue tracking the same core indicators established during the original self-assessment:

Energy • Endurance • Exercise Performance • Recovery • Resting Heart Rate • Sleep

With Playbook B, however, pay particular attention to what happens during training and recovery.

Does training energy become more stable?

Does exercise capacity change?

Can you maintain performance deeper into the workout?

Does recovery between sessions change?

Does overall endurance begin moving?

We're looking for a pattern across the protocol, not a great workout here or a bad workout there.

The objective is to determine whether metabolic performance is actually changing.

With a 12–16-week protocol, that longer observation period also gives us more time to determine whether changes are becoming consistent and sustained rather than interpreting short-term fluctuations as meaningful results.

🧪 REASSESSMENT

At the completion of the 12–16-week protocol, return to the same self-assessment used before beginning.

Compare the overall picture with where you started.

The question is not simply whether you completed the protocol.

The question is whether there has been a meaningful and sustained change in energy utilization, exercise performance and recovery.

If there has been, that's useful information.

If there hasn't been, that's useful information too.

🏁 PLAYBOOK B — FUEL & TUNE THE ENGINE

The strategy is deliberately sequential:

LOAD → FUEL → SIGNAL → TRAIN → REASSESS

Days 1–15: Establish the L-carnitine foundation.

Weeks 3–12/16: Use L-carnitine and MOTS-c only on resistance-training days.