Tuesday, January 14, 2014

52 more lessons from another year of weekly writing

This week, I marked two full years of writing weekly articles on science and running for Runners Connect.  Last year, I made a list of one thing I learned about running from each week of writing, and I'm doing the same this year.  The shorter and more focused nature of my articles on Runners Connect allows me to cover a huge number of topics, which is reflected in the list below! Check out RunnersConnect.net for the full articles, as well some guides to injuries that I've written and a ton of other really useful information on running as well.

1.    Massive increases in training volume and intensity are likely to result in overtraining, a problem where your body responds hostilely and normal adaptation mechanisms fail.  Avoiding this is not just a matter of your training, though—getting more sleep and keeping your overall stress level low also helps keep you safe from overtraining.  If you are overtrained, it can take several weeks to work your way back to health.

2.  Because bones have a unique healing timeframe, the standard "increase mileage by 10% per week" rule might not work best for people susceptible to stress fractures.  Two ways to make sure your body can handle new mileage territory is by taking a down week every 3-4 weeks as you increase mileage, or using an "equilibrium" model, where you increase mileage by 30% one week, then maintain that same volume for several weeks before increasing again.

3.  For ideal performance, there's a balance between having a stiff, responsive surface and a little bit of "give" so you can get a lot of energy back from the ground.  On a soft surface like grass, you can get away with wearing the thinnest, lightest spikes you have, but on pavement, you probably want something with at least some cushioning.

4.  Some innovative new studies have connected hamstring tightness with increased stress on the plantar fascia and abnormal loading in the forefoot. 

5.  Many runners get extremely sore calves after their first race of the season.  This is because they spend the entire offseason training in regular running shoes, then run an entire race in low-heeled racing flats or spikes.  To avoid this, do some strides in low-heeled shoes (or in no shoes at all) a few times a week, even during parts of the year when you aren't racing. 

6.  The four best exercises for hip strength are the clamshell, side-step (or "monster walk"), glute bridge with single-leg lifts, and quadruped hip extension (pictured below).  If you're only going to do a few strength exercises, do these!





7.  The most common locations for runners to get stress fractures are the tibia, the metatarsal bones, and the fibula (in that order).  Together, these account for over 90% of stress fractures in runners.  Within this group, half of tibial stress fractures occur in the first "third" of the bone, and the most commonly fractured metatarsals are, in order, the second, third, and fourth.

8.  There's no evidence right now that any style of footstrike is, by itself, "superior."  It may be that footstrike is like pronation: an aspect of your running form that varies from person to person and changes what kind of injuries you are likely to get, but not necessarily injury rates overall. 

9.  Having allergies to dust or pollen nearly doubles your risk for having asthma, and being an endurance athlete already increases your risk for developing asthma.  Moreover, many runners have asthma without even knowing it! Cold air and pollen are the major aggravators for asthmatic runners, meaning winter and spring training can be difficult.

10.  Finding the right medications to manage asthma can be tricky, so be prepared to work with your doctor and try out a few different approaches before you get it right.

11.  In theory, drinking water every 10-15min "to thirst" as you run is optimal.  It's okay to lose some water weight while running; you don't need to replace every drop of sweat you lose with water or sports drinks.  Most people will find that drinking one 12 or 16-ounce bottle of water per hour of running will keep them from getting thirsty, which is the best measurement of how much water you need.

12.  A rare subset of stress fractures are "high-risk" stress fractures, meaning they are prone to slow and sometimes incomplete healing.  These include femoral neck stress, navicular, and fifth metatarsal stress fractures, among others.  Fortunately, early diagnosis and treatment can mean that these don't have to be career-changing or ending injuries.

13.  Female runners with a history of stress fractures should consider taking a calcium and vitamin D supplement, as there is some evidence that this can lower your risk for stress fractures in the future.

14.  There is emerging evidence that your vitamin D levels can have a significant impact on your overall health and ability to recover.  You're at a greater risk for vitamin D deficiency if you have dark skin, live far from the Earth's equator, or spend very little time outside.  Exposure to direct sunlight and vitamin D supplements can both raise your vitamin D levels.

15.  Healthy runners might get some benefit from doing single-leg balance training to reduce the risk of ankle sprains, but these exercises are most useful to people who already have a sprained ankle and want to recover quicker and prevent sprains in the future.

16.  The glute bridge exercise with leg lifts and single-leg squats are two excellent tests for measuring hip muscle function.  People with poor hip strength or coordination tend to let their pelvis drop when doing single leg lifts while doing glute bridge, and their knee buckles or rotates inward when they do single-leg squats.  Poor hip strength and coordination are also very closely linked to running injuries, so these tests can be a useful screening tool.

17.  Polluted air has a huge impact on your body's ability to perform.  Heavy smog can saturate up to 5% of your red blood cells with poisonous carbon monoxide, and ozone can impair your oxygen intake by 11%.  The link is so strong that high school cross country times can be predicted by the amount of pollution in the air.  Pollution also increases your risk of getting respiratory infections like the cold, and severely aggravates asthma.    

18.  High pollen counts can wreck a workout if you have allergies.  Though the direct effects on performance are untested, exposure to allergens has been shown to decrease the function of the central nervous system, which could impair your running ability.  Make sure you talk with your doctor if you are a top-level high school, NCAA, or open/masters athlete, as you might need a therapeutic use exemption for some allergy medications.

19.  To avoid gastrointestinal problems while running, avoid meals that are high in fiber, fat, and concentrated carbohydrates (like fruit juice) immediately before running.  Also be aware that high temperatures and dehydration can cause GI problems like nausea, diarrhea, cramping, and bowel movement urgency too, and know that women are particularly prone to GI issues, though the reasons are unclear.

20.  Keeping your shoes laced snug, but not tight, and making sure you have enough room in the toebox of your shoe will help alleviate bruised toenails.  Keeping your toenails trimmed short and square and using an "ankle lock" lacing pattern can help, too.

21.  Carrying around excess weight will slow you down by about 1.4% per 1% of body weight increase, but these measurements are from carrying around artificial weight, like water bottles or camelbaks.  Keep in mind that losing weight, especially rapidly, is associated with muscle loss, so your best bet is to maintain a healthy weight all the time, not try to cut down to a "racing weight" several times per year.

22.  Women are more likely to get patellofemoral pain syndrome (runner's knee), medial tibial stress syndrome (shin splints), and IT band syndrome than men.  Women should be particularly attentive to their hip strength, as they tend to have worse hip mechanics than men, which might explain why they get knee and shin injuries more often.

23.  Men are more likely than women to get tendon and fascia injuries like patellar tendonitis, Achilles tendonitis, and plantar fasciitis, though were' not quite sure why.  Men are also overrepresented among injured runners with calf strains, knee osteoarthritis, and meniscus injuries, though to what extent this is simply because there are more older men who run is unsure.

24.  Older runners, especially men, need to keep in mind that their risk of calf injuries increases as they age.  Strengthening your calves is probably a good idea for prevention if you are a master's runner.

25.  A few new studies indicate that whether you have high or low arches doesn't affect your overall injury risk, but it does impact where you get injured.  Runners with high, stiff arches are probably more susceptible to bony injuries and problems on the lateral (outside) side of their foot, ankle, and leg, while people with flat, flexible arches look to be more vulnerable to soft tissue injuries on the medial (inside) half of their foot and leg.

26.  Very thin or very firm shoes can increase the pressure on the sole of your foot and put more stress on your metatarsals, especially if you run on hard surfaces.

27.  Scientific studies have been skeptical of the usefulness of Active Release Technique (ART) and Graston Technique to treat injuries.  Despite anecdotal support for these deep-tissue massage techniques, there's not much well-designed research supporting their efficacy.  

28.  Balance training can help athletes recover from ankle injuries, but you should probably avoid it if you currently have an overuse knee injury like IT band syndrome or patellofemoral pain syndrome (runner's knee).

29.  Extracorporeal shockwave therapy is an emerging treatment which has shown promise for treating chronic tendon and fascia injuries in athletes.  Firm standards on how to best use it as a treatment protocol are, realistically speaking, 5-10 years off; until then, it's best thought of as an experimental treatment. 

30.  Women should avoid tight-fitting pointed-toe shoes as much as possible.  Some evidence suggests that these shoes can cause bunions, and wearing well-fitted, comfortable shoes certainly can't hurt. 

31.  Unstable surfaces like Bosu balls, balance mats, and the like should only be used for strength exercises which specifically target improving balance.  "Compound" exercises like squats, lunges, or push-ups are best done on flat, stable ground.

32.  Side stitches are poorly understood, but research suggests that taking more time between eating, stretching your abdominal muscles, and running and avoiding concentrated, sugary drinks before and during running can alleviate your problems.  Spinal mobility might be related to chronic side stitches in some athletes, so consider seeing a chiropractor or physical therapist if you have chronic side stitch pain while running.

33.  Platelet-rich plasma (or PRP) therapy is an emerging but still experimental treatment for a range of running injuries.  Studies on its efficacy are conflicting, so if anything, it should be reserved for long-standing, recalcitrant cases of patellar tendonitis, Achilles tendonitis, and plantar fasciitis.

34.  Research indicates that the best benefits from pure sprint workouts can be netted by doing six sessions of sprint training spread out over several weeks.  These workouts should consist of a small number of very short (30 seconds or less) repeats at maximum or near-maximum effort, with plenty of recovery. 

35.  Therapeutic ultrasound, a mainstay of athletic training rooms and physical therapy offices, does little or nothing to improve recovery.  Most of the effects on your body can be accomplished just as effectively with a simple hot pack.

36.  Specific exercises to strengthen your lungs or improve your airflow don't have any impact on your ability to run because your lung capacity is not a limiting factor in distance running.  Because of this, lung-strengthening contraptions and airflow improvers like Breathe Right strips offer no benefit to runners.

37.  Women who have foot deformities like bunions, neuromas, and hammertoes are vastly more likely to wear shoes that are ill-fitted and too small for their feet.  Do your best to wear comfortable, well-fitted shoes as much as possible—trendy women in New York City walk to work in comfy athletic shoes, then put on their high-heeled dress shoes once they get to work!

38.  Iontophoresis, a method of delivering drugs through the skin which uses an electrical current instead of a needle, appear to be able to deliver corticosteroids to an injured area without incurring the type of damage that's been associated with corticosteroid injections.  Some small studies have supported iontophoresis as a useful adjunct to a traditional rehab program for Achilles tendonitis and plantar fasciitis.

39.  Nitroglycerin, delivered to an injured area via a skin patch, shows some very promising results in early studies on treating tendon injuries.  For now, they are an experimental, off-label treatment for nitroglycerin patches, which are typically used to treat chest pain in people with heart disease.

40.  People who play ball sports like basketball or soccer before becoming runners have a substantially lower risk for developing a stress fracture while running.  Every year you played a ball sport before becoming a runner confers a 13% reduction in the incidence of stress fractures.  For women, this relationship only holds if you had normal menstrual periods (i.e. were not amenorrheic) during your tenure as a ball sport player.

41.  When returning to running after a soft-tissue overuse injury like Achilles tendonitis or patellofemoral pain syndrome, some research indicates that it's okay to run with some mild pain, as long as that pain does not climb above 5/10 on the pain scale and fades by the following morning. 

42.  Research published in the last year indicates that poor hip strength and stability are associated with medial tibial stress syndrome, also known as shin splints.  Doing a hip strength routine is a very good idea in general, but especially if you have a history of shin problems.

43.  Cold, windy, and wet weather increases your risk for hypothermia—that should be obvious.  But runners who are young, tall, and thin, as well as those who run at a slow pace, are also at a greater risk for hypothermia, even in only moderately cold or wet weather.  Fortunately, cold weather is not nearly as much of an impediment on race day as hot weather, at least as measured by medical tent visits at major road races.

44.  Running outside in the cold will make your shoe feel stiffer, as the EVA foam that makes up the midsole becomes significantly harder in cold temperatures.  Shoes with softer midsoles are modestly less susceptible to this problem, but still harden substantially in cold temperatures.

45.  Healthy runners are pretty good at keeping impact forces under control when they are fatigued from running fast.  Runners with a history of injury, however, don't appear to adapt as well to fatigue and experience greater impact when tired vs. healthy runners.

46.  Going for long, continuous runs, which results in exertional fatigue (a different phenomenon than the metabolic fatigue that results from fast running) again does not have a major impact on the mechanics of healthy runners, but runners with knee injuries show a pronounced increase in abnormal hip mechanics after a prolonged run.

47.  Epsom salt soaks, an old-school low-tech treatment for overuse injuries, don't have much in the way of proof for their efficacy.  You are better off spending your time and energy on treatments with more evidence supporting them.

48.  Even though running shoe companies can make some outlandish claims about how effective the technology in their latest and greatest shoes is, your body seems to be smart enough to not be deceived into changing how you run based on what you hear about a shoe.

49.  Dimethtyl sulfoxide, or DMSO, is a chemical which has some profound effects on the core biology of your body, and even though it's been touted as a treatment for overuse injuries by alternative medicine advocates, there's no scientific proof it has any benefit.  Don't waste your time or money on such an exotic and powerful chemical.

50.  Most evidence indicates that overuse injuries are not related to inflammation.  Though the "inflammatory theory" of running injuries popularized traditional treatments like icing, compression wraps, and anti-inflammatory drugs, the most successful injury treatments have nothing to do with modulating or reducing inflammation.

51.  Lactose intolerance can cause GI problems in runners who are not aware that their stomach can't handle lactose, a sugar present in dairy foods.  A doctor can administer a lactate tolerance test to definitively establish whether or not your body can handle lactose.

52.  Calcium and protein work together to strengthen your bones.  Too much protein and not enough calcium can cause a net loss of bone mass, and increasing your consumption of calcium doesn't seem to be an effective way of increasing bone mass unless it's accompanied by an increase in protein intake, too. 

I hope you've learned a few things from this summary of another year's worth of writing.  I certainly have! Best wishes to your training and racing in 2014.

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