Which Comes First, Cardio or Weights_ - Alex Hutchinson [104]
How caffeine does work is still up for debate. Caffeine is a stimulant, and it may also carry a placebo effect for some athletes—but that’s not the whole story either. “If I were to place electrodes on your muscle, and start to stimulate it so that your muscle is contracting and your brain’s not involved, I can still see an effect [from the caffeine],” Graham says. The current theory is that caffeine directly affects how muscle fibers contract at a cellular level, making each fiber contract more strongly when it receives a signal from the nervous system.
Caffeine, however, is not the same thing as coffee. The only rigorous study directly comparing the effects of caffeine (in pill form) with coffee was performed in Graham’s lab. Surprisingly, he and his colleagues found that only pure caffeine produced a performance boost, even when the level of caffeine in the bloodstream from coffee was identical. “We didn’t believe it at first, so we kept adding subjects,” he says, “but the data just got stronger.” Other studies have found a performance-enhancing effect from coffee, so Graham is cautious about overstating his results. What is clear is that the effects of coffee, with its complex mix of bioactive ingredients, are far harder to nail down than the unambiguous effects of pure caffeine.
Current estimates suggest that somewhere between 82 and 92 percent of North American adults consume coffee on a regular basis. The use of caffeine explicitly for its performance-enhancing qualities is also widespread: a British study published in 2008 found that 60 percent of cyclists and 33 percent of track and field athletes took caffeine to enhance athletic performance. International-caliber track athletes were twice as likely to seek a boost from caffeine as club-level athletes. But Graham sounds a note of caution about the value of a caffeine-fueled personal best for recreational athletes, who are typically focused on beating their own best performances rather than beating specific competitors. In effect, it simply moves the finish line closer. So despite all his research, Graham has never used caffeine in 20 years of running marathons.
Does competing in front of a crowd improve performance?
One of the unique aspects of running is that ordinary weekend warriors have the opportunity to toe the starting line right next to the fastest runners in the world and run through the streets of big cities with thousands of spectators cheering them on. In fact, some major races like the Marine Corps Marathon in Washington, D.C., draw big crowds of spectators without any elite runners at all. Not surprisingly, many runners aim to set their personal best times at these races, reasoning that the energy of the crowd will help propel them forward. But does it really make a difference?
Researchers have been studying the effect of spectators on sports performance for years, in an attempt to understand the well-known “home advantage” experienced by professional sports teams. This effect is thought to stem from a wide variety of factors such as biased officials, travel-weary opponents, and elevated testosterone in home-team players eager to protect their home turf. While you’d think the crowd would be a key part of home advantage, a surprising study published in 2010 by Niels van de Ven of Tilburg University in the Netherlands shows that this isn’t necessarily the case.
Van de Ven took advantage of two quirks of the schedules of Italian soccer leagues during the 2006–2007 seasons. First, he examined 20 games that were played in empty stadiums, since the home teams were being penalized for misbehaving fans and safety infractions. After carefully controlling for the quality of the teams, he found that the same home advantage existed with or