HARRISBURG -- Though we may not be experts on corrections law, we law-abiding citizens have seen enough prison movies to grasp that inmates are to be afforded their daily exercise. We see inmates playing basketball, inmates lifting weights and, in the just-released revival of "The Longest Yard," we see them playing football, too.

But is daily physical activity a right, or is it a privilege to be granted at the discretion of prison wardens? And what, precisely, constitutes "physical exercise?" What happens if it's raining outside? The state's Commonwealth Court will consider those questions soon because of a lawsuit filed by an inmate being held in a Clearfield County prison.

Gary Kozlowski, who was jailed almost a decade ago after committing a string of armed robberies in downtown Philadelphia, is suing the state Department of Corrections, asking the court to force prison officials to allow two hours of daily exercise time for each inmate. The law he's citing, penned in 1923, seems to be squarely on his side.

Every prisoner, the law says, "shall have at least two hours daily, physical exercise in the open, weather permitting." If the weather is bad, the two-hour exercise period is to take place indoors, as long as the indoor exercise is "safe and practical." The law has since been updated, for inclusion in Pennsylvania's master statutes code, but it uses similar language: "Jails shall provide all prisoners at least two hours daily, physical exercise in the open."

But Kozlowski says that's not the case at the jail in Houtzdale, north of Altoona.

Sometimes, when the outdoor session is canceled due to inclement weather, jail officials offer TV time, card games and other diversions, but no exercise, called "blockout" time at the prison, according to the lawsuit. Other times, prison officials allow inmates to use the jail's indoor gym, but not for a full two hours.

Either way, Kozlowski says, the two-hour rule is being violated.

But the Department of Corrections, in responding to Kozlowski's complaint, pointed to the "safe and practical" clause in the 1923 law, suggesting that this language gives wardens discretion, and anything that is discretionary is, by definition, not an absolute right, but a privilege that may or may not be granted.

So the state's attorneys suggested the original complaint, filed in September, was moot, essentially admitting that the facts in the complaint were probably true, but were also irrelevant from a litigation standpoint, because exercise time is discretionary. They asked the court to dismiss the case.

Commonwealth Court disagreed this month, rejecting the state's request. In other words, Commonwealth Court says the case must go on.

How will the case play out? History is in Kozlowski's corner. In a similar case from 1981, Commonwealth Court ruled that the exercise period is mandatory, and that prisoners have a statuary right to an exercise period of at least two hours.

Kozlowski is further asking the court to come up with a definition of physical exercise. Kozlowski suggests the definition encompass any activity that "strengthen[s] the body through burning calories, [or] working the heart and body muscles through some form of physical exertion." Playing cards, he suggests, does not amount to physical exertion.

Even though the suit specifically targets the state prison, a Commonwealth Court ruling in Kozlowski's favor would be enforced at county jails, not just at state-run prisons.

That's because the applicable law doesn't distinguish between state prisons and county jails when it comes to physical exercise, said William DiMascio, director of the Pennsylvania Prison Society. In fact, state law requires that county jails adhere to the state's guidelines, providing the opportunity for two hours' exercise.

Locally, wardens say their jails are meeting those requirements. At Allegheny County Jail, inmates are allowed to use the gym throughout the day, starting at 8 a.m., and periodically into the evening. There is no outdoor exercise, though, because Allegheny County's is a high-rise jail, unlike the sprawling complexes that can be found at more rural and suburban prisons. Instead, the gym has a wire mesh ceiling.

"We call it fresh-air exercise," said Ramon Rustin, the warden there.

Inmates at the Beaver County Jail have the opportunity for four hours daily of outdoor exercise, weather permitting. If the weather is bad, the indoor gym is open for use, Warden Bill Schouppe said.