The 41-yearold actress is best known for playing spoilt neurotic Rachel in popular spoilt neurotic 20/30 something’s sitcom Friends. This month the perennially single beauty is looking trim while advertising ‘electrolyte-enhanced Smart Water.’

Aniston looks undeniably brilliant, but is that to do with this magic water? Or is it more to do with having the readies to pay for a personal trainer and a chef that cooks you really healthy and not bland as plaster dinners? What the hell are electrolytes anyway? Oh hi Wikipedia, you’ve arrived just in the nick of time…

In physiology, the primary ions of electrolytes are sodium(Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl_), hydrogen phosphate (HPO42_), and hydrogen carbonate (HCO3_). The electric charge symbols of plus (+) and minus (_) indicate that the substance in question is ionic in nature and has an imbalanced distribution of electrons, which is the result of chemical dissociation. All known higher lifeforms require a subtle and complex electrolyte balance between the intracellular and extracellular milieu. In particular, the maintenance of precise osmotic gradients of electrolytes is important. Such gradients affect and regulate the hydration of the body, blood pH, and are critical for nerve and muscle function. Various mechanisms exist in living species that keep the concentrations of different electrolytes under tight control.

Okay, so they do do something, but we still question the need for this water. We think Jennifer just works out really hard, fuelled by the fear of loosing her career and being alone…That’s the best motivation!

More Jennifer here.