While it's good news that more people are answering the call to increase physical activity, it's bad news that many are getting injured. Sports injuries--such as muscle cramps, a joint injury, or lower back injury--can quickly derail your fitness routine or training program. Part of your treatment will include applying an ice pack or heat therapy such as a hot pack. But, you need to know which one to use and when so you don't aggravate the injury and delay healing.

Use an Ice Pack When Sports Injuries First Occur

An ice pack is one of the best initial treatments for acute sports injuries such as bruises, ligament sprains and muscle strains. It's best to use it within 24 to 48 hours of the injury occurring. You may be familiar with the term RICE treatment, which stands for Rest, Ice, Compression, and Elevation. Using an ice pack for about 15 to 20 minutes, along with the other three therapies, minimizes swelling to the injured area. Also, cold is a vasoconstrictor--it constricts blood vessels--and helps to control pain.

Delay Heat Therapy When Sports Injuries First Occur

Although heat therapy is more comfortable than using an ice pack, it's a vasodilator, which means it dilates blood vessels and increases circulation. The increased blood flow drives inflammatory chemicals and oxygen to the area, which will increase pain in a newly injured area. Plus, warmth can also increase bleeding.

However, once 48 to 72 hours has passed, use heat therapy for sports injuries to rev up blood flow, remove cell debris from damaged tissues, and to bring much-needed nutrients and oxygen to the area to enhance healing. Heat therapy also prevents fluid buildup and relieves stiffness around the injured area.

Use an Ice Pack or Heat Therapy for Chronic Sports Injuries

If you have a nagging sports injury such as tendonitis, muscle spasms or cramps, both an ice pack and heat therapy can provide relief. They're also effective remedies for osteoarthritis, which may result from injuring your joint while playing sports or exercising.

When used for chronic or overuse injuries such as tendonitis, an ice pack reduces inflammation and provides pain relief. Apply cold therapy after activity, not before. Heat therapy also suppresses pain, plus, it relieves soreness, stiffness and increases range of motion. Apply heat before exercise or playing sports.

Take Precautions

You can use an ice pack on sports injuries several times a day, but never for more than 15 to 20 minutes at a time. Never put it directly on your skin; place a cloth or towel between your skin and the ice pack to avoid getting an ice burn. Also, avoid cold therapy if you're extremely sensitive to cold, or you have poor circulation or high blood pressure.

When using heat therapy--hot packs, heating pads, or a warm bath--make sure it's warm and not hot, so you don't burn your skin. If you have a condition that affects your circulation such as diabetes or a vascular disease, you may be less sensitive to heat and run a higher risk of burning yourself. Never apply heat to an open wound or inflamed joint, and avoid it if you have dermatitis.

A recent review of studies on topical heat creams published in the Cochrane Database of Systematic Reviews suggests they may be more effective for pain caused by chronic injuries than acute injuries. Plus, the best creams contained a non-steroidal anti-inflammatory such as aspirin (studies on creams containing capsaicin were excluded from this review, but capsaicin is an effective pain reliever). Still, many users swear by heat creams for relieving pain from sports injuries. If you use one, watch out for any skin irritation.

Don't fall asleep when using an ice pack or heat therapy for sports injuries. Also, if heat therapy doesn't provide relief, quit using it.

Sources: The Merck Manual Online Medical Library, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Mayo Clinic, and The You Doctors, Dr. Mehmet Oz and Dr. Michael Roizen.