Thursday, March 31, 2011

Hot weather exercise: How to keep cool

How hot weather affects your body

Exercising in hot weather puts extra stress on your heart and lungs. Both the exercise itself and the air temperature increase your body temperature. To dissipate heat, more blood circulates through your skin. This leaves less blood for your muscles, which increases your heart rate. If the humidity is high, your body faces added stress because sweat doesn't readily evaporate from your skin - which only pushes your body temperature higher.

Under normal conditions, your skin, blood vessels and perspiration level adjust to the heat. But these natural cooling systems may fail if you're exposed to high temperatures and humidity for too long. The result may be a heat-related illness, such as heat cramps, heat exhaustion or heatstroke.

How to avoid heat-related illnesses

To keep it cool during hot-weather exercise, keep these basic precautions in mind:

  • Take it slow. If you're used to exercising indoors or in cooler weather, take it easy at first
  • Drink plenty of fluids. Your body's ability to sweat and cool down depends on adequate rehydration. Drink plenty of water while you're working out - even if you don't feel thirsty. If you're planning to exercise intensely or for longer than one hour, consider sports drinks instead. These drinks can replace the sodium, chloride and potassium you lose through sweating. Avoid drinks that contain caffeine or alcohol, which actually promote fluid loss.
  • Dress appropriately. Lightweight, loose-fitting clothing promotes sweat evaporation and cooling by letting more air pass over your body. Avoid dark colors, which can absorb the heat. A light-colored hat can limit your exposure to the sun.
  • Avoid midday sun. Exercise in the morning or evening - when it's likely to be cooler outdoors - rather than the middle of the day. If possible, exercise in the shade or in a pool.
  • Wear sunscreen. A sunburn decreases your body's ability to cool itself.
  • Have a backup plan. If you're concerned about the heat or humidity, stay indoors. Work out at the gym, walk laps inside the mall or climb stairs inside an air-conditioned building.

Know when to call it quits

During hot-weather exercise, be on the lookout for heat-related illness. Signs and symptoms may include:
  • Weakness
  • Headache
  • Dizziness
  • Muscle cramps
  • Nausea or vomiting
  • Rapid heartbeat

If you suspect a heat-related illness, stop exercising and get out of the heat. Drink water, and wet and fan your skin. If you don't feel better within 60 minutes, contact your doctor. If you develop a fever higher than 102 F
(38.9 C) or become faint or confused, seek immediate medical help.

Regular physical activity is important - but don't let hot-weather workouts put your health at risk.

by Mayo Clinic staff

Tennis Elbow

Lateral epicondylitis, more commonly known as tennis elbow, is inflammation, soreness, or pain on the outside (lateral) side of the upper arm near the elbow.

There may be a partial tear of the tendon fibers, which connect muscle to bone.
The tear may be at or near where these fibers begin, on the outside of the elbow.

Causes & Symptoms

When you use these muscles over and over again, small tears develop in the tendon. Over time, this leads to irritation and pain where the tendon is attached to the bone.

This injury is common in people who play a lot of tennis or other racquet sports, hence the name "tennis elbow." Backhand is the most common stroke to cause symptoms.

However, any activity that involves repetitive twisting of the wrist (like using a screwdriver) can lead to this condition. Therefore, painters, plumbers, construction workers, cooks, and butchers are all more likely to develop tennis elbow.

This condition may also be due to constant computer keyboard and mouse use.

Signs and Tests

The diagnosis is made based on signs and symptoms, because x-rays are usually normal. Often there will be pain or tenderness when the tendon is gently pressed near where it attaches to the upper arm bone, over the outside of the elbow.

There is also pain near the elbow when the wrist is extended (bent backwards, like revving a motorcycle engine) against resistance.

X-rays are rarely needed.

Calling your health care provider

Apply home treatment (over-the-counter anti-inflammatory medications and keeping the elbow still) if:
  • Symptoms are mild
  • You have had this disorder before and you are sure you have tennis elbow
Call for an appointment with your health care provider if:
  • This is the first time you have had these symptoms
  • Home treatment does not relieve the symptoms


To help prevent tennis elbow:
  • Apply an ice pack to the outside of the elbow
  • Maintain good strength and flexibility in the arm muscles and avoid repetitive motions
  • Rest the elbow when bending and straightening are painful


1. Regan WD, Grondin PP, Morrey BF. Elbow and forearm. In: DeLee JC, Drez D Jr., Miller MD, eds. DeLee and Drez's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier;2009:chap 19.

2. Schmidt MJ, Adams SL. Tendinopathy and bursitis. In: Marx JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2009: chap 115.

Muscle of the Week:

Wrist Extensors

Other Names
  • Forearm (outer or back)
  • Hand Extensors
  1. Extensor Digitorum
  2. Extensor Carpi Radialis Longus
  3. Extensor Carpi Radialis Brevis
  4. Extensor Carpi Ulnaris
  5. Extensor Indicis
  6. Extensor Digiti Minimi
  7. Extensor Pollicis Longus
  8. Extensor Pollicis Brevis
Radial Deviation

  • Grasp half loaded dumbbell with plate on thumb side. Position arm down to side.
  • Bend wrist so weighted side is pulled upward. Lower until weighted side is pointing downward. Repeat.
If half loaded dumbbell is not available, one of two substitutes can be used.
  • Empty metal bar: to increase resistance grasp further away from center with longer end on thumb side.
  • Standard dumbbell: grasp so pinkie side is against inside of weight plate.

Wrist Rollers

  • Stand behind weight plate(s) on floor and grasp wrist roller handle with both hands; over hand grip.
  • With left hand gripping handle, relax grip of right hand and slide grip in front of handle (by flexing wrist) and regrip. Relax grip of left hand and hyperextend right wrist. Repeat sequence with opposite hands, alternating back and forth until weight plate has raised up near hands. Lower weight steadily with opposite movement.