The idea of the epic theatre marathon isn't new – but it raises fascinating questions about how much an audience is prepared to put up with

In Tom Stoppard's one-acter The Real Inspector Hound (1968), which depicts the press night of a spoof Mousetrap-like murder mystery, one of the reviewers confides to another before the performance begins: "Me and the lads have had a meeting in the bar and decided it's first-class family entertainment but, if it goes on beyond half-past ten, it's self-indulgent."

This exchange satirises a common view among theatre professionals that drama critics conspire as a pack, but also touches on a genuine truth about theatre-reviewing – and, more generally, theatre-going. Regardless of what applies in other areas of life, length definitely does matter in theatre.

The duration of a play is significant to critics because they are working to a deadline: although print editions of most titles contain fewer overnight (filed at curtain down) reviews than used to be the case, blogs and websites have created a new market for rapid verdicts. But it's also of concern to audiences, not only because of transport connections and baby-sitting arrangements but because live drama is an art form that demands intense concentration in a dark warm space at the end of what is for many people a working day. I confess to having blinked in alarm at the clocks on the box office walls at the National Theatre, which show the start and finish times of plays, sometimes mentally willing back the hour hand of the second to the previous notch.

So last week's opening of Gatz at London's Noel Coward Theatre can be seen as a gamble. This production of F Scott Fitzgerald's The Great Gatsby, transferred from America, starts at 2.30pm and runs until 10.30pm, although there is "only" six and a quarter hours of performance, the rest being intervals between the four acts.

But, while attendance at Gatz requires flexible diaries and reliable bladders, the production should benefit from what I'd argue is a curious rule of theatrical running times. In the case of very short (under 90 minutes) and very long (six hours plus) shows, the duration becomes, in many ways, a selling point; something that marks out the show as interesting or out of the ordinary. If anything, it's plays in the three-and-a-half to four-hour range that pose a problem. Psychologically, there's an exhilaration from knowing that we'll be home to see Huw Edwards reading the headlines, or an adrenaline boost from the thought that we and the cast are being asked to work for a third of a day or more. It's the middling spans - the programme note that says: "this production will run approximately three hours and forty five minutes with one interval" - that threaten aches and yawns.

The explanation for this, I think, is that there is a natural human fascination with the possibilities of stamina, both as a participant and an observer. It's for this reason that walking and running marathons are such popular events, and why it was perhaps inevitable that theatre would create equivalents such as Gatz, the RSC's epic Nicholas Nickleby in the early 80s (eight-and-a-half hours), or the all-day sessions at the National Theatre in which David Hare's state-of-England trilogy (Racing Demon, Murmuring Judges, The Absence of War) and Tom Stoppard's The Coast of Utopia trilogy were staged in morning, afternoon and evening performances.

I remember both the Hare and Stoppard marathons ending with audience and cast applauding each other, a gesture that acknowledged the physical and mental endurance that are the point and pleasure of such clock-buster productions. Still, we were mere sprinters in comparison with viewers of the early work of Ken Campbell (1941-2008), theatre's most persistent thief of time, which included a 22-hour staging of Neil Oram's The Warp, its length exacerbated by the requirement for audiences to be on their feet for much of the action.

So Gatz is an American cousin of Campbellesque theatricality, testing the physical limits of the transmission and reception of drama. But, at the other end of the scale, there has been a trend towards swift, interval-free productions that offer ticket-buyers the chance of being on the way home (or in a restaurant) by 9pm. The 90-minute Art – Christopher Hampton's anglicisation of Yasmina Reza's 1994 play – began this fashion, and there have been many subsequent brief evenings, with the sprinter market currently served by the National Theatre's 100-minute Antigone and the Sheffield Crucible's 80-minute rendition of Pinter's Betrayal, both served up without a break for drinks.

Interestingly, the current West End revival of Eugene O'Neill's Long Day's Journey into Night, a play by a dramatist with a reputation for expansiveness, includes in its adverts the line: "Two-and-a-half hours including interval." As some previous productions have for approaching four hours, this is a tribute to the skillful editing of director Anthony Page and the rapid rhythm of actors David Suchet and Laurie Metcalf. But it's also a comment on our time-conscious culture that the producers felt the need to stress this point, much as, during hot summers, playhouses advertise their air-conditioning.

However, the irony of the lines from The Real Inspector Hound, with which I started this piece, is that they appear in a play that runs for around an hour and so has always troubled producers: it is usually paired with something else, either Sheridan's The Critic or Stoppard's own After Magritte. These days, though, a West End management might get away with offering Inspector Hound on its own for the short-form market or in a seven-hour package of all Stoppard's shorter work. Length sells, as long as the measurements are extreme.