8.30am on a clear thursday morning in venice, Los Angeles, and Robert Downey Jr has got that glint in his puppy-dog, brown eyes - the very same one that had him nominated for an Academy Award by the age of 27 for Chaplin; the same one that is a talismanic mainstay of two multimillion-dollar movie franchises, Sherlock Holmes and Iron Man, currently making Downey, against all odds, the "Biggest Film Star On The Planet"; and the same one that played its part in having him arrested in April 1996 after he was stopped by police speeding on the Pacific Coast Highway while in possession of cocaine, heroin and a .375 calibre Magnum handgun. It's a glimmer; an unquantifiable article. But it's there all right, swimming deep within the actor's soft vitreous gel, somewhere between the iris and infinity; always has been, always will be.Yesterday, when we met for the first time - the 45-year-old actor throwing kung-fu pirouettes at me while squeezing my biceps and gauging the strength of my build - he promised a "restorative work-out. We're not going to kill you, duuuude." Sounding every bit the keenly protective father figure, Downey added reassuringly: "It's about health." Now, facing the grinning actor in his low-key private gym, the Santa Monica Body Building Center (the same sweat shed where Sylvester Stallone trained for Rocky), I feel like I've walked blindfolded into a carefully engineered bear trap for gung-ho journalists who fancy their chances at out-ironing the Iron Man.
"Now, this," Downey declares to the room, walking over to a vast structure of white painted steel that resembles a cross between a sex swing dreamt up by Philip K Dick and a medieval torture rack, "is what we call, 'the War Machine'." Looking at the spherical tangle of pulleys, weights, clips and twisted metal, I kick myself for picking out the fly-away Orlebar Brown running shorts and teeny-tiny wife beater this morning, rather than the chain-mail vest. Or the Hurt Locker-style bomb-disposal suit. "You've got some serious Chariots Of Fire duds going on there," beams Downey, effervescing wicked glee. The smile drops: "Wait till Jimmy shows you the sledgehammers."
Watching Downey pump it as if his life depends on every lift, it's clear he works on pure instinct. Gwyneth Paltrow, Oscar winner and Downey's love interest, Pepper Potts, in the Iron Man movies, concurs: "Robert's greatest skill as an actor is his versatility; his ability to play many things at one time: incredulity with an undercurrent of self-referential humour, pathos with warmth, triumph with a hint of frailty; whatever the combination, there are always many levels to what he is conveying. And he can do it in any accent." As for the ride Downey provides for those working with him on set, she adds: "I don't think I have ever seen Robert stick to a script; he is the most fly-by-his-seat-actor I have ever worked with."
Dressed to sweat in black jogging bottoms, a cherry-red T-shirt, elbow guards, black trainers and a black, woolly beanie, this particular morning Downey may look like a well-rehearsed gym bunny, but out of the three other times I encounter him over these two days, his outfits never stray too far from "comfy". He seems to dress like a reserve astronaut perennially on stand-down due to bad weather.
As he squats and sips an energy drink in the corner of the gym, an old war wound on his shoulder being strapped up by Jimmy, his Irish-American bodyguard, while his trainer of five years explains to me, somewhat unconvincingly, how Downey's work-outs are about "partnership" rather than "punishment", I notice there's something uncannily simian about Downey's physicality. Perhaps that's why he prefers such soft, stretchy elastic cotton clothes. They give him room to roll, to bank, to bounce, to coil, to remain fluid - to stay on high alert. Downey is, and has always has been, about energy - physical, contained, unleashed or otherwise. The wattage coming off the guy makes the other bodies in the room - even the unit that is Jimmy, who's inked-up like a Manhattan-bound A-train, an Iron Man motif down his left calf, the digits 221b on the underside of his forearm (how's that for devotion?) - orbit him like spare moons.