Running in winter
The colder days are slowly approaching this year, but they are still appropriate for running trainings. After Ljubljana marathon, the most important running event in Slovenia, the runners disappear because November is reserved for regeneration after a whole year of toiling. But when the Christmas period starts, the new running season opens as well, at least for the most persistent runners. Days become colder and if we’re lucky some snowflakes already fall from the sky and cars have to be equipped for winter conditions. And so does our “running machine” – it’s waiting on suitable winter equipment and ride 😊. This article is addressed to those who like to run in a cold weather and to those who avoid warm environment even in winter. It’s divided in several different sections: in the first section you can read about energy and muscle function, the second section is about the dangers of running in cold weather and the third section is about the equipment for winter “festivities”.
Low temperatures have a negative effect on the musculature. In the neuro-muscular system a cold muscle responds slower, although the nervous system endeavors to keep a high level of activation. Researches show that the cold causes changes in muscle fiber and its responsiveness, which decrease muscle action, strength and contraction. One experiment with the temperature of muscles (not air) showed that the subjects whose muscle temperature was between 25°C and 35°C were slower and the energy consumption was bigger. This is why running in cold weather poses a risk – your body temperature could drop and consumption of energy could increase, the running speed could lower, which makes you more prone to injuries.
ENERGY and METABOLIC RESPONSE
It is a known fact that the consumption of energy increases in cold weather. It’s also known that free fatty acids and some glycogen are consumed during low activity. In cold weather the ratio is changed: free fatty acids are consumed less than in warm weather, which gives glycogen a bigger role. The low level of blood sugar (glycogen) is problematic because the shivering increases and body temperature drops lower than it drops when the level of blood sugar is high. Highly intensive training can get younger and less experienced runners exhausted faster and lead to a lower temperature of the body core.
ERISKS OF HYPOTHERMIA
For human thermoregulation a change in body temperature by just a few degrees can be fatal for the vital functions of the organism.
Hypothermia is reduced body temperature below the normal body temperature, also reduced body temperature in rectum measuring below 37°C. The functional limit of hypothalamus is reached at 34.5°C. Below that temperature, the hypothalamus can no longer regulate the mechanisms for maintaining the temperature which can lead to hypothermia, losing consciousness and coma. Some may think that I exaggerate, but I think that runners need to know what’s happening in their bodies.
EFFECT ON RESPIRATORY ORGANS
In cold weather breathing through nose is warms the air, but only to a certain temperature. The core of the body is cooling with cold air and consequently the temperature is dropping down. At 0°C of air temperature the air in the nasal cavity drops to a temperature of 15°C, in trachea to 20°C. The temperature of air in the lungs is 30°C, which is approximately 6.5°C lower than the normal body temperature. At lower temperatures the breathing volume and frequency can decrease. The core of the body is substantially cooling more.
Besides the cold air runners have to battle very detrimental atmospheric particles PM10. The PM10 particles can be solid particles or dust. The most detrimental to our health are particles of 10 micrometers in a diameter. These particles come to our lungs by air we breathe in and reach our lungs, vascular system and heart. The solid particles highly increase mortality rate from respiratory and cardiovascular diseases. These particles also consist of heavy metals, which means they’re even more harmful. Before you head off to a foggy and less windy area, check the levels of PM10 particles here: http://www.arso.gov.si/zrak/kakovostzraka/podatki/PM10_napoved.html.
Frostbites can occur already at 0°C. When running at 5km/h the temperature drops to −5°C, at sprints at 16km/h it drops to −24°C. The skin is poorly circulated with blood because the body contains the temperature in the core, around the heart and digestive system, so the most exposed body parts are nose, cheeks, ears, fingers and toes.
I hope I haven’t scared you too much because my intention is only to describe the dangers you might face while enjoying winter running. It’s important to know that running in winter, when the temperature is below 3°C, is different than running in normal conditions. That’s why you need a winter equipment, although you might feel equally comfortable with the regular equipment. However, when running, the body shouldn’t be cooling down and you shouldn’t encourage it with unsuitable equipment. The first layer of clothes is very important. I would recommend sweat-wicking sportswear, so the body is not cooling down and your temperature is higher and you are more “productive”. It’s recommended that the next layer be a cotton sweatshirt which will soak in the sweat, then wear two layers of cotton sweatshirts which keep you warm, then a thermal fleece shirt and a wind-jacket. Some manufacturers make running equipment which protects the chest and shoulders from wind, and the back is covered by material that breathes and soaks out the moist and contains warmth. Thermo running leggings are also recommended to protect you from cold. If the temperatures are really low, you can wear sweats over the leggings or thermal underwear, but only if they aren’t too tight. You should have suitable winter running shoes preferably made of Gore-Tex waterproof material, with specially designed soles for winter running and better stability. When you’ll put on your regular shoes in spring, you’ll “fly” because winter shoes are slightly heavier and stiffer than the regular ones. Protect your head with a woolen cap, put some ventilated gloves on. I also recommend a scarf and a running mask which covers your mouth and nose. This will allow you to warm up yourself and the air you breathe.
There you go, you’re ready for running in winter weather. Go on a non-intensive running on short tracks, suitable for winter time because the consumption of energy in winter is higher than in warm weather. For long-distance running combine jogging and race walking. You are ready to run into winter carelessly – with good equipment and well-prepared.
Zelo pomembna so prva oblačila, ki jih oblečete na kožo. Najbolj priporočljive so športne ali „švic“ majice, saj iz kože odvajajo pot in jo sušijo. S tem so ustvarjeni pogoji, pri katerih se koža ne hladi, s tem pa sta višji telesna temperatura in vaša „storilnost“. Na to majico je priporočljivo obleči bombažno majico, ki vpije pot in ga zadrži, nato dve plasti bombažnih majic, ki grejejo, ter termo flis in anorak, ki vas ščiti pred vetrom. Nekateri proizvajalci izdelujejo tekaško opremo, ki ščiti prsni koš in ramena pred vetrom, hrbet pa prekriva material, ki diha, odvaja vlago ter zadrži toploto. Priporočljive so tudi termo tekaške hlače, ki vas bodo ščitile pred mrazom. Če je temperatura zelo nizka, lahko poleg termo hlač oblečete še trenerko ali si pod tekaške hlače nadenete termo smučarsko perilo, vendar le, če vas ne tišči. Nujno potrebujete primerne zimske tekaške copate, najbolje iz Gore Tex materiala, saj ne prepušča vode, s posebno oblikovanim podplatom za zimski tek in boljšo stabilnostjo. Ko boste spomladi obuli običajne športne copate, boste poleteli, saj so zimski malce težji in trši. Za zaščito glave uporabite volneno čepico, za roke kakršne koli rokavice, najbolje pa take, ki dihajo. Poleg tega priporočam šal ali tekaško podkapo, ki jo lahko potegnete čez usta in nos. S tem boste ogreli sebe in zrak, ki ga vdihnete.
Tako, pripravljeni ste za tek v zimskem vremenu. Privoščite si za zimo običajen nizko intenziven tek in krajše ture, saj je pozimi poraba energije večja kot v toplejšem vremenu. Za daljše ture pa združite jogging in hitro hojo. Pa brez skrbi v zimske dni – z dobro opremo in dobro pripravljeni.