You’re doing everything right. So why is your HRV flat?

You train five days a week. You sleep seven and a half hours. You’ve cut the second coffee and the midweek drink. Your wearable says your recovery is fine, and fine is exactly the problem - the trend line stopped climbing about eighteen months ago and hasn’t moved since.

There is a reason for that, and it isn’t your training.

Heart rate variability measures the gap between consecutive beats. Wide, irregular gaps mean your nervous system is relaxed and doing maintenance work. Narrow, metronomic ones mean it’s still braced. That’s why HRV drops the morning after a hard session and climbs back once you’ve absorbed it - and why how fast it returns matters more than the number itself.

The work being reported on is repair, and repair is cellular. Which means HRV is downstream. It’s an output, and like any output it can only be as good as what’s feeding it.

Look at what you’ve actually changed over the last two years. Training load, periodised. Sleep, tracked and protected. Alcohol, mostly gone. Protein, creatine, magnesium, vitamin D. Every one of those is a behaviour or a raw material - an instruction sent to the cell, or a delivery made to it.

None of them changes the cell’s capacity to act on any of it. That’s the layer nobody optimises, because no wearable reports on it and no protocol asks you to. It’s also the layer that determines what the rest of your effort converts into - which is why the trend line can flatten while every input above it is still improving.

NAD⁺ is a coenzyme present in every cell in your body. Mitochondria use it to turn food into energy; repair enzymes need it to fix damage. Without enough of it, the machinery still runs, but slower and with less margin.

Two systems consume most of it, and both run hardest overnight: energy production, which is non-negotiable, and repair, which is deferrable. They draw on the same pool. When supply is short, energy wins and repair gets what’s left - so a slow HRV recovery is less a nervous system that won’t relax than a repair queue that didn’t get funded.

NAD⁺ declines steadily with age. By your forties you’re operating on roughly half what you had in your twenties - and training hard raises demand at exactly the point supply is falling. Nothing has gone wrong. You’re doing the same work with fewer resources to recover from it, and the trend line is telling you so.

Three jobs, no overlap - produce NAD⁺, protect it from being broken down as fast as it is made, and give the cell what it needs to spend it. Every dose is at the level used in the research it comes from, printed in full on the label. No proprietary blends, no fillers, nothing you can’t check against your own stack.

There are no stimulants in it, so there’s nothing to feel in the first hour. What you’re buying is capacity, and capacity shows up in the data before it shows up as a sensation.

MUTO was formulated by Dr Richie Barclay and reviewed by a six-person scientific advisory board before a single capsule was made. It’s produced in a UK facility to GMP ISO standard and tested by an independent lab for purity and potency.