Which Comes First, Cardio or Weights_ - Alex Hutchinson [7]
• Do you feel pain in your chest when you do physical activity?
• In the past month, have you had chest pain when you were not doing physical activity?
• Do you lose your balance because of dizziness or do you ever lose consciousness?
• Do you have a bone or joint problem (for example, back, knee, or hip) that could be made worse by a change in your physical activity?
• Is your doctor currently prescribing drugs (for example, water pills) for your blood pressure or a heart condition?
• Do you know of any other reason why you should not do physical activity?
This may be cold comfort for people who swear they are overcome by coughing fits or throat pain when they exert themselves in subzero conditions. For a long time, people have blamed “exercise-induced bronchoconstriction” (EIB), an asthma-like narrowing of the airways that leads to shortness of breath and coughing, on cold air. The condition affects between 4 and 20 percent of the population—but it’s the dryness of the air, not its temperature, that triggers the response.
The dryness-versus-coldness debate has been raging in scientific circles for many years, but recent experiments by Kenneth Rundell, a researcher at Marywood University in Scranton, Pennsylvania, who spent 10 years as an exercise physiologist with the United States Olympic Committee, have essentially settled it. In a study published in the journal Chest, Rundell found that warm, dry air triggered the same response as cold, dry air in 22 EIB sufferers riding stationary bikes. The reason is that the cells that line our airways are highly sensitive to dehydration, and breathing hard during exercise means more dry air rushing past these cells.
There are some makeshift solutions. For example, wearing a scarf or balaclava over the mouth can moisten the air as it is inhaled. “That makes breathing more difficult,” Rundell notes, so it’s less useful for skiers or runners in competition but may be fine in training. Commercial heat-exchange masks, which accomplish the same thing with less breathing resistance, are also available. If the EIB symptoms are serious—and confirmed by a lung-function test administered by a doctor—asthma medication can provide relief.
For most people, it’s safe to assume that, short of an asthma attack, exercising outside in the dead of winter is perfectly safe. Even without EIB, some people do experience a burning sensation in their throat or upper airways when they exercise in the cold, Rundell says, “but that’s just a response of the nerve endings.” In other words, even if it feels like you’re freezing your lungs, you’re not—so you might as well keep going.
When is it too hot to exercise?
Heat is more than just an inconvenience, as we’re reminded almost every summer when we hear the inevitable reports of a football player dropping dead from heat exhaustion during a grueling practice. Since 1960, there have been 128 heat-related deaths among football players at the high school, college, and pro levels—and there’s really no excuse for this to keep happening.
The basic steps to avoid danger are straightforward: stay hydrated, schedule workouts for the coolest parts of the day, stay out of the sun, shorten workouts, take more rest, and reduce intensity. But how hot does it need to be for these steps to become important? That depends on who you are and where you are. If you’re obese, out of shape, or dehydrated, you’ll be much more susceptible to heat exhaustion. And if you live in a part of the country that’s usually cool, you’ll be more at risk in a sudden heat wave than people farther south who are acclimated to hot temperatures.
One reassuring fact to note is that we’re generally pretty good at automatically adjusting our effort under hot conditions. In fact, when researchers at the University of Cape Town asked volunteers to cycle for 20 kilometers in 95°F (35°C) temperatures, they found that the volunteers’ brains adjusted to the hotter-than-usual conditions right from the start, before they’d had a chance to start overheating, by automatically signaling