Well: Does Exercise Really Boost Your Mood?

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There exists a large and soothing body of scientific literature suggesting that regular exercise can improve someone’s mood and fight anxiety. And then there is this experiment from Germany, in which researchers placed running wheels in the cages of a group of laboratory mice and let them exercise at will.

Mice generally love to run, and these rodents spent almost every waking hour on their wheels, skittering through more miles than most animals are allowed to complete during exercise studies, averaging about seven miles per mouse per day. The scientists, from the Central Institute of Mental Health at the University of Heidelberg, then placed these avid runners in unfamiliar situations. What they found was surprising, in part because it contradicted earlier experiments by other researchers. The mice froze or quickly fled to dark corners, behaviors considered by some researchers to signify anxiety. It was as if the marathon runners in this experiment had become more anxious and neurotic than the nonrunners, presumably because of the volume of their running.

The apparent implication of that finding — that too much running makes an animal a nervous wreck — might seem disconcerting. But as this study, published in the journal Hippocampus, and additional new research makes clear, a great deal still needs to be understood about just how exercise affects mood.

To date, most research into the interplay of exercise and anxiety has focused on the actions of various neurotransmitters or chemical messengers within the brain, like serotonin and dopamine. But the German researchers weren’t looking at neurotransmitters. Their interest was in a different brain mechanism. They were trying to determine whether the formation of new brain cells, a process called neurogenesis, was making their lab animals nervous.

Exercise spurs neurogenesis, a finding confirmed by seminal research completed a few years ago. This neurogenesis would seem to be completely laudable, since it occurs mostly in the hippocampus, a portion of the brain associated with memory and thinking. Rodents that have exercised and that have brains fizzing with new neurons tend to score well on tests of memory and cognition.

But the effects of neurogenesis on mood are murkier. A number of neurological case studies have reported that people and animals with lesions in the hippocampus — meaning fewer brain cells in that region — are less prone to anxiety than other people.

So could high volumes of running and the commensurately large amounts of neurogenesis in the hippocampus produce anxiety? The German work seemed to say yes, particularly a follow-up experiment by the same scientists published in September in the online journal PLoS One. In that study, the researchers radiated the brains of mice to prevent neurogenesis, and then let them run. The treated mice eagerly took to their wheels, but grew almost no new neurons. Afterward, placed in stressful situations, they remained calm, reacting much like sedentary mice.

It seemed that neurogenesis had been the culprit behind the earlier runners’ excessive anxiety.

But the scientists are quick to point out that these findings do not mean that human marathon and ultramarathon runners are necessarily at risk of developing mood problems. The “exercise schedule of mice is not comparable to human fitness training,” wrote Dr. Johannes Fuss and Dr. Peter Gass, the primary authors of the two studies, in a shared e-mail response to questions. With very rare exceptions, humans will not spend their entire waking hours running.

More important, it’s not clear whether the behavior of the nervous mice was necessarily anxiety as we might experience it. The exercised mice did frequently freeze and hide, but they are prey animals, a situation that does not reward insouciance. To be less anxious, if you are a mouse, Dr. Fuss and Dr. Gass wrote, “might not always be the best survival strategy.”

The German scientists, in focusing narrowly on neurogenesis, may also have underestimated the intricate and broad ways in which exercise affects the brain’s mood centers. A fascinating series of experiments conducted at Princeton University and presented at the 2010 annual meeting of the Society for Neuroscience in November showed that neurons born from running actually behave differently from other neurons. They are not as physiologically excitable, even in stressful situations. The Princeton scientists showed that after a rodent stress test, the hippocampi of running mice contained fewer proteins associated with neuron activity than the brains of sedentary mice, even though the runners had more neurons over all. The runners’ brain cells had remained, it seemed, more calm in the face of stress. Similarly, the scientists found, areas of the brain that would normally shoot stimulating messages to the hippocampus during and after stress were quieter in exercised mice.

“Thus,” the Princeton researchers concluded, “running may reduce anxiety-like behavior” despite increasing the number of new brain cells. Exercise had recalibrated the animals’ brains so that they were more serene.

What this emerging science means for those of us who regularly exercise is, admittedly, still being teased out by researchers. But other recent studies are encouraging. A review article published last year in The Archives of Internal Medicine, for instance, concluded that compared with sloth, “exercise training significantly reduced anxiety symptoms” in a group of people at risk for mood problems. And in a beguiling experiment also presented at the 2010 Society for Neuroscience meeting, scientists from the University of Oklahoma found that female rats allowed to run at a moderate pace for 10 to 60 minutes several times a week — my exercise regimen, in fact — behaved with robust mental health in stress tests. So whether you run on two legs or four, the message may be: relax.

 

In Scotland, the Only Match That Really Matters May Matter Too Much

But if the popular name for their clashes sounds benign, it has become a cruel euphemism over the years, conveying nothing of the hatreds and lurking violence that characterize what may be the oldest, and the most dangerous, crosstown rivalry in all of sports. If sports are a metaphor for life, the Rangers-Celtic story is one of age-old Protestant and Catholic enmities that are one of the ugliest strains in Scotland’s history.

Late last week, those tensions seemed to reach a new extreme with the disclosure that four crude bombs were sent through the mail to Celtic’s manager and two of the club’s most prominent supporters over the last six weeks. All were intercepted or reported to the police before they could explode, but spokesmen for the police said their components were capable of inflicting serious harm. British news media reports suggested they contained flammable liquids and nails.

The police say they will deploy unprecedented numbers of officers at the Rangers-Celtic match on Sunday, a game that could go a long way toward determining the winner of the Scottish Premier League, which Rangers lead by a point over Celtic. Police spokesmen said they would arrest anybody at Rangers’ Ibrox Stadium whom they catch giving voice to sectarian slogans or songs that have been the motif for the teams’ games for as long as anybody can remember.

So far, there have been no arrests for the intended bombings, and the police have not disclosed whatever information they may have on suspects or possible motives. But a police official, who did not want to be identified discussing a developing investigation, said inquiries were focused on the sectarian hatred between the clubs. The police raided homes in Glasgow on Saturday morning and arrested two men, 23 and 27, for posting “sectarian and hate-filled” comments on unspecified Web sites. More raids are expected as part of an continuing campaign focusing on online soccer forums.

According to statements by the police and the intended victims, the bombs were sent to the Celtic manager, Neil Lennon; to Paul McBride, a lawyer who has represented him; and to Trish Godman, ?a former politician in Scotland and a prominent Celtic fan. In interviews since the case went public Thursday, Lennon, 39, a Catholic from Northern Ireland who had a successful career as a player in England and in Scotland, said he had received bullets through the mail before the two bombs that were mailed to him.

In an interview that was quoted in most of Britain’s major newspapers Saturday, he described the bombs as "a tipping point."

He added: “Hopefully, all this rubbish can stop. It has nothing to do with football, and we’re all fed up with it. We’re all fed up with the singing, fed up with the abuse, and we just want to do our jobs.”

Suggesting the turnaround could begin with Sunday’s game at Ibrox, he added: “There might be a few sympathetic voices in the ground, which would be nice. But I am not looking for sympathy. I am looking to go there and win a football match.”

His counterpart at Rangers, Walter Smith, a former manager of Scotland’s national team and of Everton in the English Premier League, was less sanguine. In interviews, he told reporters that the Old Firm environment was too toxic to enjoy, and that if he had not already announced his retirement from Rangers at the end of this season, the mailing of the bombs would have prompted him to question his staying on anyway.

“After the happenings of the last week, I’ll be delighted that it’s my last one,” he said, referring to Sunday’s game.

The enmities between the two clubs have their roots in the 19th century, when waves of Irish migrants fleeing famine and the seizure of their land by British authorities crossed the Irish Sea and settled in western Scotland, many around Glasgow. About three-quarters were Catholics, a quarter Protestants, and they brought with them the sectarian hatreds that had festered in Ireland.

“They decanted their historic tensions and hatreds to western Scotland and Glasgow,” Tom Devine, a professor of Scottish history at the University of Edinburgh, said in telephone interview.

In time, the animosities found expression in the two soccer teams, and in the so-called “90-minute bigots” who pack the stands. Celtic, which plays in green-and-white stripes, was founded in 1888 by a Catholic priest, partly to counter religious persecution. Rangers, whose colors are the blue, white and red of Britain’s Union flag, drew mostly Protestant support. From the start, the underlying loyalties — Protestant and Catholic, British and Irish — lent strong passion to their encounters. Yet these seem to have intensified even as their original causes have eased. Religion has declined in an increasingly secular Scottish society, and 13 years have passed since Catholics and Protestants in Northern Ireland concluded the Good Friday agreement that has brought at least a fragile peace.

That has led Devine and others who have studied the issue to say that the enmities now are more tribal than religious, and fueled by poverty and social breakdown. Glasgow, Scotland’s largest city, has pockets of poverty that are among the most extreme in the developed world. The Catholic minority, particularly men from 18 to 35, has traditionally been among the poorest, and has suffered “a bigoted anti-Catholicism in certain sections of society,” Devine said. ?

In the most deprived areas, encompassing crumbling public housing towers ravaged by joblessness, and alcohol and drug abuse, male life expectancy is 54 — four years lower than in war-torn Sudan — according to World Health Organization figures.

In the soccer rivalry, the resentments have often found expression in violence, but soccer authorities have been slow to act. Rangers were fined $12,000 last week by UEFA, soccer’s governing body in Europe, after its fans continued singing sectarian songs at high-profile matches, including one that urges those of Irish origin to “go home,” and another, “The Billy Boys,” that includes the refrain “We’re up to our ears in Fenian blood,” Fenian being a derogatory term for Irish republicans. Celtic supporters have refrains of their own, including “The Fields of Athenry,” an old Irish republican ballad.

Magnus Linklater, a Scottish journalist writing in Saturday’s Times of London, said the tribalism appeared to have crossed Scotland’s class divide.

“Among the baying fans are lawyers and accountants, whose language is often as extreme as the thugs they stand alongside,” he wrote.

Like many others, he called for the police to crack down hard, beginning with Sunday’s match.

Ally McCoist, the assistant manager of Rangers and previously a longtime player for the club and for Scotland’s national team, agreed.

“I honestly don’t know what more the clubs can do,” he said.

Scotland’s first minister, Alex Salmond, who is facing a difficult election next month, blamed the violence narrowly on what he called a “lunatic element,” but Devine, the historian, sees a more sinister threat.

“I think it’s ironic that in a post-Christian, secular society, the problem seems to be intensifying,” he said, adding: “What’s happened over the last few days is unprecedented. There have been riots, but sectarianism in Scotland has never had this violence and criminality.”