Watching those marathoners race by every year can inspire even those who have never run before to lace up their sneakers. But before you decide to hit the ground running, there are a few things you should know about what running does to a person’s body — good and bad.
We asked Dr. Jennifer Baima, a staff physiatrist at Brigham and Women’s Hospital and clinical instructor at Harvard Medical School to examine the sport.
Impact on muscles and joints
According to Dr. Baima, the impact running has on your muscles and joints depends on what kind of runner you are: “There are basically two types of runners,’’ she said. “Those that heel strike and those that mid-foot strike.’’
Heel running is the more common way to run since padding in contemporary running shoes may encourage this type of gait. Recent studies have suggested this leads to increased forces at the knee joint. It is not yet known whether this leads to increased injury.
Some people land first on their mid-foot. This usually occurs in people who run barefoot. Since this is thought to cause less wear and tear on the body, it has led to the recent trend in barefoot (or minimalist footwear) in running.
“We used to think running increased hip and knee arthritis because of the frequent pounding, but studies have not proven this,’’ Baima says. Light to moderate running has no adverse effect. Heavy running may predispose patients to osteoarthritis of the hip or knee. Pace may be more important than distance in hip osteoarthritis. Of note, osteoarthritis is more closely related to obesity, malalignment, or prior injury than running pace/ distance.
Baima says common injuries include:
Greater trochanteric pain syndrome: The greater trochanter is the part of the thigh bone that pokes out to the side.
Anterior knee pain: This refers to pain in the front of the knee. It can come from a meniscal tear or arthritis, but the most common problem in runners is poor tracking of the knee cap with repetitive bending and straightening of the knee.
Stress fractures: They usually occur in the feet and shins.
Plantar fasciitis: The irritation of the soft tissue that covers the bottom of the foot.
Subungual hematoma: A bruise under the toenail
Baima cites several benefits to running including improved endurance, lower blood pressure, increased oxygen delivery to the tissues, improved metabolism, and improved strength and bone density.
However, she also notes that not getting enough exercise can give you low bone density and too much can give you a stress fracture. “Although more common in runners, stress fractures are not as common as soft tissue injuries from running. If left untreated, stress fractures typically cause pain earlier in the run,’’ she says.
Baima says that a negative point to running is that the potential for injury is always there. Plus, she says, it may not be safe for you to run where you live. But Baima stresses that “given the obesity epidemic, there are far more patients who are in pain from not working out than there are who get sports injuries.’’
Stress fracture prevention tips
Baima suggests these five steps:
1. Start slowly – Increase distance by no more than 10% per week. Do not run every day. Give yourself a day off in between.
2. Make sure you get enough calcium and vitamin D. It is OK to wear sunscreen. It is inevitable that you will miss a spot, and 10 to 20 minutes of bright sunlight is likely all that you need for vitamin D. No need to risk skin cancer when you can take a vitamin D supplement.
3. Avoid caffeine. It amps people up and can encourage training through an injury.
4. Do not run barefoot without proper training. (I would say do not run barefoot at all, but choose a very thin-soled shoe. There is no telling what you might step on in the city.)
5. Change your footwear every six months or 500 miles or sooner if you start to feel pain.
Greater trochanteric pain syndrome prevention
Baima’s tips for pain prevention:
1. Warm up with dynamic stretching.
2. Cool down with static stretching.
3. Use a foam roller to release tension in the sides of your legs after running.
4. Combine strength training with running, especially hip abductor exercises. Static stretching = the usual way. Bend over and touch toes – hold position Dynamic stretching = stretching in motion. For example: Run sideways while twisting your hips.
Before starting a running program, Baima says you should check with your doctor if you have a heart or lung condition. Your doctor may want to order a stress test if you have a family history of heart problems and you may also need treatment if you have asthma or allergies.
Other exercise options
Baima recommends using an elliptical trainer “since it is easy on the joints and it is a very efficient way to exercise.’’ Biking works similar muscles, but not the exact same muscles, she said.