The Strength Research Hub

Strength is the capacity to produce force. Power is the capacity to produce it quickly. They are related, and they decline at different rates.

Muscle is composed of fibres with different contractile properties. The fast-twitch fibres, which generate force rapidly, are lost preferentially with age. This means a woman can retain a reasonable amount of muscle and still lose a disproportionate amount of the ability to produce force quickly. That ability is what recovers a stumble, what rises from a low chair without using the arms, what descends stairs under control.

Preserving power therefore requires training that recruits those fibres. Fast-twitch fibres are recruited by high force demand. Light resistance performed many times does not reliably reach them, whatever else it accomplishes. This is the central reason that load matters more than repetition count for this particular outcome.

Why loading is a signal, not just a stress

Muscle and bone are both mechanosensitive. They possess cellular machinery that detects mechanical strain and translates it into a building response. The strain must exceed a threshold to be detected as a signal worth responding to.

In muscle, high-force contraction activates pathways that increase protein synthesis. In bone, the strain produced by muscles pulling on their attachments, together with impact, deforms the mineralised matrix and prompts osteoblasts to build. This is why resistance training appears in the evidence for both muscle and bone, and why activities that do not load the skeleton meaningfully, whatever their cardiovascular or balance benefits, do comparatively little for bone density.

The signal is also specific. Bone strengthens where it is loaded. Muscle adapts to what it is asked to do. Neither generalises far beyond the demand placed on it.

Training supplies the signal. It does not supply the material. Muscle rebuilt after a session is rebuilt from dietary amino acids, and bone from minerals delivered with their cofactors. A strong training stimulus met by inadequate substrate produces less than the training deserved.

How Silvie evaluates the evidence

We select ingredients by form, not only by name. The form determines how much of a nutrient reaches the tissue that needs it, and two products naming the same compound can differ substantially in what the body absorbs. Where a specific form has been used in the human trials, that is the form we use.

We dose to the levels tested in those published trials rather than to the smallest quantity that permits a claim on the label. A dose below the studied range is not a smaller version of the same effect. Often it is no effect at all.

We prioritise human studies. Mechanistic and animal research is useful for understanding why something might work, but it is not evidence that it does. Where the human evidence is mixed, preliminary or limited to a narrow population, we say so in the article rather than omitting it from the marketing.

We are also clear about what supplementation cannot do. Nutrition supplies the material for adaptation. Training supplies the signal that directs it. The research is consistent that neither substitutes for the other.

You can read how we assess evidence, select ingredient forms and set doses in our approach to research.