Research has identified that the best predictors of injury are weekly mileage, consecutive days of running, and history of previous injuries (Macera et. al. 1989).  Moreover, half of all injuries can be traced back to a previous injury in the same area (Macera et. al. 1989). Interesting enough, Ven Mechelen et. al. (1993) found that the average runner could expect to be injured once every 150-200 hours of running.

Most running injuries can be tracked to one cause or a combination of causes, such as overtraining, poor flexibility, low strength, running surface, physical trauma, and running shoes.  The list of culprits is endless, for example:  1) from doing too much running too soon after an injury, running too often, running too fast and too hard, and insufficient rest between workouts; 2) overstretching and running fast without adequate warm up, 3) running on uneven surfaces, slanted or curved roads, and hard surfaces like concrete or tarseal roads; 4) improper shoe choice (running in shoes made for other sports) to running excessive mileage without changing running shoes frequently, and 5) trauma such as tripping, falling or twisting your ankle.  Moreover, poor running biomechanics, combined with any of the above is often enough to cause injury.

What pain is ok for runners?

It’s often difficult to discern between the general muscle soreness experienced after a workout, and the beginnings of an injury.  Typically, if the discomfort dissipates a day or so after the training run, or disappears after 10 minutes’ running, it’s fine to run.  However, some injuries creep up on us slowly, getting progressively worse over days, weeks, or even months, while other injuries are immediately evident.  Pay attention to both types.

General guidelines for warning signs of Injury

If you notice any of the following, you’re on the injury train, so be prepared to slow down and stop running. 

• Reduced range of motion about the joint, compared with the other side.
• Swelling, especially around the joint or on a muscle; when checking for swelling (by comparing the affected area with the non-affected area) feel for heat and look for redness in the area.
• Affected muscle does not generate as much force as its opposing counterpart.  This can be difficult to measure, but if you attempt to lift weight on one leg and you cannot lift the same weight as easily on the other leg, or if it feels painful when contracting, you have an injury.
• Numbness or tingling sensation in a body region may indicate nerve compression; these can be serious, so see your sports medicine physician immediately.
When you feel pain, take notice and heed these warning signs of impending injury:
• Pain and discomfort at the beginning of the run that becomes worse as you continue to run.
• Pain that forces you to alter (shorten) your stride or limp.
• Pain that you feel coming on after a few minutes of running and continues at a low nagging level.
• Pain that stops you running or walking.
• Pain that persists after you stop running.
• Pain that persists during and interferes with normal daily activities.
• Pain when you walk up stairs or uphill.
• Pain or stiffness especially in the mornings or after rest.
• Pain that continues for more than a day or two, worsens, and does not get better.
• Pain and tenderness in one particular spot on a bone, muscle or joint that you can actually feel with your fingertips.  You can check this by feeling the same spot on the other side of the body—if there is no pain you probably have an injury.
• If you need to take anti-inflammatory or painkilling medications such as aspirin, ibuprofen, or Tylenol.
• Dull, aching, sharp, or severe pain that keeps you awake at night.
• Pain in the joints of ankle, knee or hip.

Most common injuries with symptoms

Plantar Fasciitis- A sharp stab or deep aching underneath your foot, from the heel to the arch. It will hurt a lot first thing in the morning when you walk around, or after you’ve been sitting for a long time.

Iliotibial Band Syndrome- Pain on the outside of the knee or when you bend it at a 45-degree angle, or at the hip. 

Runner’s Knee- Tenderness behind or around the patella, usually around the center of the kneecap.  Pain increases when sitting with knees bent for a long period of time, or when climbing stairs or running uphill.

Shin Splints- Tenderness, soreness, or pain along the inside of your calf region and beside the shin.  This can also be a dull, deep, aching pain and usually happens only when you’re running.

Achilles Tendonitis- Dull or sharp pain anywhere along your Achilles tendon, but usually close to the heel.  You’ll usually feel pain when squeezing the Achilles tendon in the affected area, and may sometime feel lumps or nodules along the tendon.

Coming back from running injuries

If any of the warning signs for impending injury appear, it’s time to take some action to minimize the damage.  Above all, make sure you don’t make things worse, so stop running! 

You need to begin self-treatment immediately.  Here’s where most runners lose the plot—they wait for the injury to heal by itself, by stopping training and hoping things will work out ok.  The injury usually settles down with complete rest, but there is a 50% chance that it will recur again (Macera et. al. 1989).  Leaving an injury to heal itself usually results in a mass of scar tissue building up in the affected area, which causes problems later.  Here’s what you should do.

Self-management of your running injury

• Rest!  DO NOT RACE.
• Ice the area for 10-15 minutes, several times per day (minimum 2-3 times) for the first 3 days.  Never apply heat to a new injury.
• Compress the area firmly with a bandage (but not tight enough to stop blood flow to the area).
• Elevate the area above the level of your heart when you sleep.  Reducing the blood flow to the area minimizes inflammation and swelling.
• Stretch the affected area gently if there is no pain.

If the injury is not severe enough to stop your running, you must modify your training. Here’s how:

Frequency of running- Cut back to running every second day (or cut your frequency of running days per week by 50%).  Avoid running on consecutive days (Macera et. al. 1989).
Duration (length) of your training runs- Reduce your distance by 50%.  Initially, try jogging very slowly for 5-10 minutes.

Running intensity (speed)- Cut back on your running intensity by 1-2 minutes per mile slower than your normal training pace, or walk if running causes pain.

Running surface and terrain- Jog on a soft level surface like grass or dirt trails.  Avoid uphill and downhill running, and on hard surfaces.

Post training- Always ice the affected area after you run.  Gently stretch the affected area with one or two stretches.  Hold each stretch for 15-30 seconds.  Check your running shoes for excessive wear, and to be safe purchase a new pair.

By doing these steps, there’s a good chance your injury will turn around within a week or two so you can gradually start to increase your running again.  This is where you must develop a sense for your limits by listening closely to what your body is telling you.  For example, if your injury starts getting sore around 3 miles, then keep your running to 2 miles.  You alone can determine how much running is safely within your limits.

A good indicator that you are recovering from your injury is how the affected area feels in the mornings.  If there is no pain in the affected area in the morning or during your training efforts, you can slowly build your running backup to where you were.  However, if it’s stiff, sore, and has you hobbling around in the mornings, you may have to take the next step.

Still not getting better?

If, after a few days or a week, your pain and swelling have still not receded with the therapeutic measures, it’s time to visit your sports medicine physician.  The doctor will diagnose your injury and advise you on whether you need to stop running and take anti-inflammatory medications.  Your physician may also determine whether you need physical therapy (PT) treatment.

Physical therapists have seen your injury before in hundreds of other limping runners, so listen closely to their advice, and when they prescribe some home exercises for you, do them.  Following an in-home program will help turn your injury around very quickly.  Your PT will also perform some other magic on your injury with various modalities including ice, heat, electric stimulation, ultrasound, massage, and mobilization exercises.

Another specialist you might consider seeing is a podiatrist to see if you need some form of orthotic foot support to address any biomechanical idiosyncrasies of your running style.  If your friends have commented that you pronate a lot when you run, this may be just what you need to stay injury free while running.

You also need to be aware that feelings of hopelessness and frustration may overcome the runner with enforced time off from running.  Often the runner will completely stop all exercise. 

This practice is highly counterproductive—stopping training completely causes a dramatic reduction in VO2 max (your ability to process oxygen) and will therefore cost you many weeks of slogging to regain lost fitness (Coyle et. al. 1984).  But take heart, because many research studies have found (if your training was done correctly) that reduced training shows almost no reduction in fitness for periods of 1-15 weeks. In fact, Brynteson et. al. (1973) found that when intensity of training remains unchanged, VO2 max is maintained for 15 weeks, even when frequency and duration of training are reduced by as much as two thirds.  Houmard et. al. (1989) demonstrated that when frequency and duration of training are kept constant and intensity is reduced by one third or two thirds, VO2 max is significantly reduced.  What this means is that you can train fewer days per week, with shorter sessions—and as long as you train hard—you won’t lose any fitness.

Clearly, if you’ve been instructed not to run by your physician you’re going to have to make some choices about other types of cardio-respiratory exercise you do.  This is a good time to do some cross training.  Performing other exercises has the added benefit of developing parts of your body that are neglected by running. Other types of cardio-respiratory exercise include swimming or walking, or some of the non-impact equipment in your local fitness club, such as the elliptical trainer, stationary bike, or rowing machine.  Remember, to maintain your fitness you’ll need to exercise at a high intensity, so aim to get your heart rate above 80% of your estimated maximal heart rate.  This is difficult with stationary cycling as you will most likely suffer from localized muscle fatigue in your legs before you can get your heart rate up close to your normal running heart rate.  This is OK and to be expected.  You’ll still get a great workout from cycling.  While trying these other exercises, monitor your pain levels to make sure they are not aggravating the injury.  If you feel pain, try a different activity. You can continue with your strength-training program while injured as long as you avoid exercising the affected area. 

If you haven’t done any resistance training previously, this would be a great time to start strengthening the rest of your body.  For more information about cross training, refer to the article in Running Research News volume 24 issue 9.

Deep water running

If you want to try an interesting activity that simulates running, and is unlikely to aggravate your injury, try deep water running in your local swimming pool.  It is especially helpful for runners suffering from stress fractures where most activities tend to aggravate the symptoms.  Deep water running is done wearing a flotation vest, and really works your legs, trunk, arms, and cardiovascular system.  You can simulate interval workouts, long steady workouts, and everything in between with deepwater running. 

Research on this alternative non-impact running mode is very promising.  Several studies show that deep water running can be used to maintain fitness.  Florida State University researchers had one group of well trained male runners do deep water running for 6 weeks, while another group continued with their regular running program at the same time (Wilber et. al. 1996).  The deep water running group maintained their VO2 max, lactate threshold, and running economy for the six weeks of water running.  Another study at Brigham Young University found that 2-mile run times were maintained after 6 weeks of deep water running (Eyestone et. al. 1993). This was confirmed by a study at the University of Toledo, where trained runners who did 5-6 sessions of deep water running for 4 weeks had no change in their 5 km times, VO2 max, lactate threshold, and running economy (Bushman et. al. 1997).

Deep water running technique

Wearing a flotation belt around your waist, jump in the deep end of the swimming pool.  Simulate your running style in the water.  At first it feels uncoordinated because you’re learning a new skill, and establishing your correct posture.  If you lean forward slightly you can actually run forward, while if you remain upright you’ll run on the spot.  Either works.  Some runners like to do laps so they can measure their progress.  You will notice that your leg turnover is not nearly as fast as when running on dry land, because the water slows your movements.  You will not be able to get your heart rate up as high as you can when running. 

Research done at the Karolinska Institute in Stockholm concluded that heart rate during deep water running heart rate is about 10% lower than dry land running.  So to get full benefits of this technique, you’ll need to push yourself hard.

Deep water interval training

Interval workouts seem to be particularly effective with deep water running. Here are two sample interval workouts that you can try.

Deep Water Running Workout #1

• 5 minute warm up.
• 1 minute fast, 1 minute easy
• 2 minutes hard, 1 minute easy
• 3 minutes hard, 1 minute easy
• 4 minutes hard, 1 minute easy
• 3 minutes hard, 1 minute easy
• 2 minutes hard, 1 minute easy
• 1 minute hard, 1 minute easy

Deep Water Running Workout #2

• 6 x 3 minutes hard with 1 minute recover
• Do 2 sets

Some mistakes to avoid when returning to running

A common mistake is for the runner to rush back into his training program to try and make up for the missed running.  Never try to catch up on lost training days, as it is likely to aggravate the injury again.

When on the comeback trail your body is composed of many different systems, all integrated at different levels.  Ideally they act as a smoothly functioning unit, but when you are deconditioned or injured, and starting up again, some systems are more out of condition than others.  For example, you may notice your respiratory system (breathing) returns to condition faster than your muscular system (leg muscles).  Here, you need to be patient and wait until the slowest adapting systems catch up with the faster adjusting ones.

Rehab is an important part of coming back from an injury.  But one mistake and you’re back on the injury list, chafing at the bit to get back out on the roads.  The canny runner listens closely to his body and adjusts his workouts accordingly.  Pain sends a clear message that our tissue has temporarily reached its limit.  Ignoring this message inevitably ends in re-injury, so heed the messages your body is sending and take it slowly.

Training mistakes and warning signs of injury that Fiona ignored

1. Kept the same running shoes for more than 6 months, while doing high mileage.
2. Increased weekly mileage too quickly.
3. Ignored tightness in calf muscle.
4. Did not slow down her training runs while increasing her mileage.
5. Did not warm up at beginning of training runs.
6. Continued to speed up her training runs.
7. Kept running on calf muscle as it started cramping.