Tag Archives: heat

Proprio-what? a deeper look at balance and stability

Yesterday’s post got lots of comments; I’d like to post a bit more here to help folks understand this concept a bit deeper. Why does this idea about balance matter at all to runners? Midstance is basically single leg standing balance. However there is a difference between “reactive balance” and “proprioceptive control.”

Let’s define a few terms here:

Strength – relates to the cross-sectional area of a given tissue. This is related to the muscle’s ability to generate force. Bigger muscle, bigger force. Simple.

Proprioception: there are 3 primary things we use for balance.

  1. Vestibular  (inner ear) – If you are standing still, inner fluid is still. If you turn your head suddenly, the inner ear fluid swirls and this information goes to your brain to help determine acceleration and change in position.
  2. Somatosensory – You “feel” the ground. You have sensory receptors in your skin which allow you to feel something – light and deep pressure, vibration, heat, cold, etc. This sensation goes a long way to improve your tactile feedback to help you remain stable.
  3. Vision – We use our eyes to orient our head and trunk and let us know which way is “up”.

Note- you do have other reflexes that play a role here, but these are the primary ones that have the greatest effect.

If these 3 systems “agree” then you are using your body as best you can to achieve control in stance. So let’s look at examples of how these can change. If you are on a merry go round, your eyes see you are spinning, your somatosensory feels the body turning, and your vestibular system says you are spinning. Everything is fine. If you stop, your eyes and somatosensory system say you have stopped, but your inner ear fluid is still swirling – signals don’t agree….. and you become dizzy.

So why is it harder to close your eyes in single leg balance? Most folks are visual dominant. They rely highly on their eyes to find their position in space. The problem with this is that it’s “slow.” You need to see information, process it in the visual part of your brain, then send a signal to the part of your brain that control motion (motor cortex) to make a correction. Somatosensory information is very very fast. There is a direct relay between the sensory and motor reflexes both inside and outside the brain – resulting in fast rapid “micro-corrections” of position. Let’s use an example.

If you look at skiers, surfers, skateboarders, white water paddlers – they all have something in common – they need to make positional corrections VERY quickly – faster than they can see visually and adjust. They get good feedback about the position of their body from their hard ski edge (transferred up through a very stiff plastic boot), or the rail of the surf board (transferred through their bare feet). Each and every time they practice their sport they are refining their position sense by “feeling” where the body is. They consistently train and improve their somatosensory system.

Research shows that the somatosensory system is highly trainable. Its best done frequently in small doses. Instead of trying to balance on one leg for 10 min each night, its better to do it 20x’s a day for 30 seconds. Yes, you CAN improve your balance….by practicing.  Not your “I’m-rocking-back-and-forth-like-a-weeble-wobble” re-active balance, but your “proactive balance.” Proactive balance means “I know what to do to keep my body stable – I can micro-correct to improve my stability.” Think about spreading your toes out wide to maximize the width of your foot. Try to push your big toe down – not curling, just down as you keep it straight. This will improve your muscles firing inside your foot. I’ll make a deal with you – if you work on your single leg balance every day, you’ll find not only will you be able to stand with eyes closed, but also be able to begin to rotate left and right with your eyes closed. The goal is to reduce your dominance on vision and improve your use and perception of “feel.” It works!

OK – so let’s now look at this with respect to running. I’m going somewhere with this I promise – I’m building a case for you. There is a ton of research that supports the idea that firm surfaces offer better “feel” to the individual and thus better balance control. Soft surfaces mute the feedback to the person and result in poor stability in stance. The goal is to maximize your level of active stability control that your body can produce.

If I am in the clinic working with a patient, I always work them in barefoot, and will use all kinds of rocker/wobble/rolling boards to do this. All of these are FIRM and HARD surfaces. Even though the foot is moving, the contact between the ground and the foot is solid. The person gets good feel for what is happening. I am not a proponent of foam pads to work on balance. Why? Foam pads let you cheat and roll off to the outside of the foot. They don’t mandate that you activate the big toe. They don’t train “pro-active control.”

Let’s take this idea and now apply is to footwear and the entire rationale for you reading this post. What is traditional footwear? – It’s got an elevated heel, a wider lever arm than your foot, and a big marshmellow stuck underneath. This marshmallow allows your weight to shift to the outside of the foot. The heel-higher-than-the-forefoot provides a “rocker” in front of the shoe that you can simply roll off of. It lets you “cheat” by conforming to your foot. A lot of runners have gotten used to this.  Their feet have become weaker as the shoe does more of the work.

When we look at minimal footwear or barefoot running, this foam pad is gone completely or reduced significantly.  Suddenly, you can’t cheat. You have to actively use the muscles inside the foot to stabilize. The absence or reduced cushioning in the shoe allows you to get better “feel”  – why do so many proponents of barefoot and minimalist running claim that they feel “free” or like they’ve “been released”…….? It’s simple – your foot gets more information from the surface you are on when you don’t have a big piece of compressible foam in the between. More information  = better muscle activation.

I see a hand up in the audience.

Q: So I’ve been running for years and I still can’t stabilize with my eyes closed. What gives?

A: closing eyes might be slightly overkill, but you know what? – Almost every standardized assessment for balance testing has an eyes-closed component to assess just what we mentioned above (the 3 things that impact proprioception). So if you have good balance with eyes closed, I know that you are good in this regard and not going to ask you to add this into your training program. It allows the examiner to differentiate how well you use different skills that affect balance. If the eyes closed part is the issue, and this is connected to faulty foot and ankle mechanics during running, it give me more information as to what your limiters are as a runner.

Q:  So I’ve been running for years, and I still can’t stand on one leg – even with my eyes open. What gives?

A:  There is no research to show that your poor balance will result in injury, but there is research to show that those with a number of lower extremity injuries do have poor balance. Further, I’ll be happy to say that those with poor single leg balance almost always have some very interesting finding in our lab – they usually have altered forces around the ankles which results in abnormal stresses to the lower leg and foot. Improving your single leg balance is a way work on prevention. I’d much rather you not get hurt and keep enjoying your runs, than not. Maybe you are one of the lucky ones who has run for years without injury – awesome! However, research shows that 82% of you runners will be hurt at some point. Both personally and professionally, I’d rather see you in the 18% of those who are not.

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Adjust your thermostat, adjust your expectations

Wow. If you are on the east coast like we are, we don’t have to tell anyone that its been H.O.T.
“But wait……..don’t the weather gods know I supposed to be training for the ___ championship in __weeks ….not to mention the ___ race I’m doing this winter. My workout today was slow, and I felt bad on my long workout this weekend. I’m getting slower and this heat is killing my training!!!!!”
If you guys want some tips on running in the heat, there are some great words of wisdom on this blog if you scroll down. Let’s re-cap: – hydrate, run in the morning, hydrate, loose fitting and light colored clothing, and hydrate. OK fine – but lets get real on this summer’s weather and why we need to take it into consideration.
Last year in C’ville, we had 7 days above 90 degrees and they were scattered about the summer. Except for a small 2 week heat wave in the middle of the summer, it wasn’t all that hot all the time. You had the luxury of moving workouts a day or 2 ahead or behind in the week based on the heat. This summer, we’ve had 45 days above 90 degrees. We’ve had 7 above 100. And let’s be honest, its not really cooling off all that much at PM or in the AM (Friday night was 96 degrees at 9:00 PM!). Its been so hot that all outdoor high school and collegiate practices would be completely cancelled in weather like this. National and State sports governing bodies have established these regulations to protect the athletes. I know – you are tougher than them and need to get your speed work session in today though…….stay with me.
Dealing with this heat is all about adjusting your expectations. Let’s  re-state this point to be absolutely clear: Trying to train at your same intensity and volume (or increasing it) in this type of weather is NOT a smart thing.

If you don’t agree with me, let’s look at it from your body’s perspective. When you exercise, you ask your body to metabolize fuel stores, regulate energy balance, and produce mechanical work so that you can move from point A to point B. All this effort produces heat. Your body has a lot of internal mechanisms to regulate body temperature, and they work pretty well. But your body has limits as to how rapidly it can cool itself off. Did you know that your body actually begins to compromise its ability to perform at around 72 degrees? Now think about how much challenge a 95 degrees environment places on that body.

Still not convinced? Let’s say that your typical Wednesday morning track work out is 12x 90 second 400 repeats, with 45 seconds between each. Think about how much stress that places on the body under normal conditions. Now let’s consider our weather reality. Its now 10-15 degrees hotter than usual and more humid. Trying to run that same workout under these conditions is significantly more stressful than typical. You may notice that you can’t make the 90 second split without taking more rest between reps. You may even notice that under these conditions, 90 seconds is not even possible. Let’s say that your triathlon training schedule has you doing a 5 hr ride on Sunday AM. However, the heat has slowed your pace down significantly after 2.5 hrs, and all you want to do is jump off the bike into a cool pool. Its OK to back off the workload to match the change in conditions – you’ll STILL GET THE BENEFIT OF THE WORKOUT. Shorten the ride. Increase your rest. Take longer breaks between intervals. Do whatever it takes to be consistent with your training, but realize that extreme weather requires some modifications to ensure we aren’t just pounding ourselves into the ground. Remember- you’re body doesn’t really know exactly how fast its going or how long a rest you are taking; it just knows that you are pushing it harder than you have in the past and with all this heat, it just might push back.

This post is written in memory of a local high school runner who died of heat illness during a summer training run.
 
 
 
 

 

Running Hot

I just got back from a midday run and it was HOT! (especially for a guy most used to running at 5:30 am). The heat of summer is here, and we must take precautions to avoid the dangers of excessive exercise in the heat. Excessive temperatures can impair performance and lead to dehydration and heat illness. Proper preparation and early recognition of heat illness will help us better enjoy our summer training.

Muscle action during exercise in our body’s main means of heat production. Only 25 percent of the energy produced by exercise is used for work or movement. The remainder of the energy is dissipated as heat. Some heat loss occurs directly to the environment when the environmental temperature is less than our body temperature. In warmer conditions, sweating is our primary means of losing heat. As our temperature rises, blood is shunted to the skin so that the heat may be lost through sweating. If heat loss does not compensate for the heat produced by muscle activity, body temperature rises. This is especially true if we allow ourselves to become dehydrated or in humid conditions where sweat loss is limited.

Heat illness can be graded as mild, moderate, and severe. Mild heat illness is termed heat fatigue and is characterized by tiredness and weakness, sometimes associated with a headache. Heat fatigue is generally responds quickly to cessation of activity and drinking fluids. Heat cramps may occur and are treated with rest, icing, stretching, massage and rehydration.

Moderate heat illness is termed heat exhaustion. Weakness and fatigue are more prominent. Other symptoms include dizziness, nausea, and even mild confusion. Treatment mandates cessation of activity, getting out of the heat, rapid cooling, and rehydration.

Severe heat illness is termed heat stroke and is a medical emergency. The runner now has an impaired level of consciousness which differentiates this more serious form of heat illness from heat exhaustion. The athlete with severe heat illness may actually have hot dry skin rather that be sweating. Immediate cooling and formal medical assistance is needed to treat heat stroke.

Heat illness can often be prevented by following some basic guidelines:

Acclimatization: If you are not accustomed to running in hot weather, gradually introduce time in hotter, humid conditions to your training. Otherwise, try to avoid the hotter periods of the day. Train early in the morning or later in the evening. Consider taking it indoors to the treadmill if it is especially hot.

Wear loose-fitting, light-colored clothing that allows moisture and heat to be lost from the body.

Proper hydration: In addition to fluids needed for daily maintenance, athletes need to replace fluids lost with exercise. Drink 2 cups of fluid 2 hours prior to exercise. Drink roughly one cup of fluid for every 20 minutes of exercise. If exercise is less than one hour, water is adequate. If exercise exceeds one hour, a sports drink will replace sugar and salt in addition to fluids. Not all of this needs to be done during exercise, but that not consumed during exercise should be replaced within a couple hours of training. Another method of monitoring fluid needs is to weigh yourself (unclothed) before and after exercise. Drink 2 cups of fluid for each pound lost during exercise. Now don’t overdo it either. Some folks adhere to the “more is better” theory. Drinking excessively, especially excessive amounts of water, can lead to hyponatremia (low salt) which can be potentially dangerous. So stick to the above guidelines and things should be fine. Also avoid alcohol and caffeine which can also promote dehydration.

Treat heat illness early. If you or a teammate experiences the signs of heat illness, stop running. Move indoors or to the shade. DRINK. Cool towels soaked in ice water can be draped over the athlete to more rapidly cool if necessary. Rapid cooling and medical attention are needed in all cases of severe heat illness.

And don’t forget about your skin. Sunblock to exposed skin to prevent sunburn!

Enjoy the summer!