| Athletes who choose the trail over the treadmill | | | | per pound of body weight daily and, during |
| don't get the benefit of a thermostat. For much | | | | exercise, feeding your muscles extra carbs (about |
| of the year in much of the United States, they | | | | five to six ounces of sports drink every 15 |
| are forced to contend with bitter cold and | | | | minutes). |
| sweltering heat. But only recently have sports | | | | Brisk |
| scientists zeroed in on exactly how those | | | | 45°F to 50°F (7°C to 10°C) |
| extreme temperatures influence performance. | | | | This is the sweet spot for sustained exercise. |
| "The biggest breakthroughs have come in the | | | | Before long workouts, heat up your muscles by |
| past five years," says Jim Cotter, Ph.D., a senior | | | | jogging or cycling slowly for ten minutes and fire |
| lecturer at the School of Physical Education at the | | | | up your nervous system with a couple of |
| University of Otago, in New Zealand. "We've | | | | 30-second bursts at close-to-maximal effort. |
| learned that the optimal warm-up for | | | | During your warm-up and the first few miles of |
| cold-weather exertion is quite different from the | | | | exercise, prevent |
| one you would carry out in the heat and, perhaps | | | | shivering€â€which can expend |
| more important, that the skin and brain play larger | | | | oxygen and promote |
| than expected roles in determining how athletes | | | | fatigue€â€by wearing layers |
| respond to temperature changes." | | | | that can be removed readily as you continue your |
| The brain, scientists have discovered, can actually | | | | workout. |
| anticipate changes in body temperature and will | | | | Balmy |
| adjust exercise intensity accordingly. This | | | | 50°F to 70°F (10°C to 21°C) |
| subconscious calculation takes into account both | | | | It's easier to get loose when it is 65 degrees (18 |
| the outside temperature and the duration of the | | | | degrees Celsius) than when it's 35 (2 degrees |
| effort, and explains why slowdowns are almost | | | | Celsius). And since muscle contraction velocity |
| automatic in the heat, even before signs of | | | | increases as sinews warm up, you can get into a |
| significant muscle fatigue set in. If an athlete | | | | groove right from the start of your workout. |
| attempts to exercise beyond the brain's wishes, | | | | However, when exercising for 75 minutes or |
| the cerebrum will respond by generating brutal | | | | more, overheating is an issue. One study found |
| sensations of exhaustion (i.e., heat strain). The sad | | | | that marathon times lengthen by 19 seconds for |
| fact: Ambient temperatures can trump your | | | | each degree above 55°F (13°C). |
| hard-earned fitness. Fortunately, though, | | | | Acclimatize by training in these temps for a week, |
| researchers have developed strategies to help | | | | and limit warm-ups to five minutes. |
| athletes stabilize their core temps in both hot and | | | | Blazin' |
| frigid conditions. Here, scientifically backed tips to | | | | Above 70°F (21°C) |
| help you perform optimally in four temperature | | | | In warm temperatures it's very difficult to shed |
| zones. | | | | excess body heat. Studies show that taking an |
| HOW TO CONQUER ANY CLIMATE | | | | ice-cold bath or relaxing in an air-conditioned room |
| Blustery | | | | prior to exercise can up endurance by 37 percent |
| Below 45°F (7°C) | | | | for cyclists and 17 percent for runners. |
| The human body has limited physiological defenses | | | | Training is important, too: When you work out for |
| for the cold. To maintain an optimal core temp, | | | | a week in the heat, you improve blood flow to |
| layer clothing properly. Also, be sure that your | | | | the skin, lower the skin-temperature threshold for |
| muscles are well stocked with glycogen (fat | | | | sweating, and sweat more evenly, all of which |
| metabolism is impaired at low temperatures) by | | | | allows you to exercise at a higher intensity for |
| consuming up to four grams of carbohydrates | | | | longer. |