Saturday, July 14

Health tips - Exercise and summer - Exercising in the heat

Physical health definition > Health tips for exercising in the summer heat

Is it safe to exercising in the summer heat?

Yes. With cautious planning one can safely exercise in the summer heat. Uncontrolled increase in body's temperature is the greatest danger  we should avoid. It is worth noting that summer itself is stressful to most of us. Adding the stress of exercising during summer has synergistic stress effect on the heart and also on the body's cooling mechanism. A high body temperature affects the brain function and the drive to exercise. Hence a carefully planned exercise regimen is necessary to cope with the temperature stress as well as exercise stress.
exercising in summer heat
Image: Cool exercise
in summer heat

Heat acclimation tips

You have to acclimate your body to exercise in summer so that your heart is not stressed much. Initially a short aerobic exercise bout of 10-15 minutes or less must be attempted. Gradually increase it to 30-60 minutes per session over a period of 10-15 days. By this gradual acclimation, at a given exercise intensity heart rate as well as body core temperature decreases whereas the sweating and cooling rate increases. The relative loss of electrolytes in the sweat also decreases with acclimation. Without acclimating even healthy persons may become stressed. Please note that the beneficial effect of acclimation will be lost and there will be rapid de-acclimation, if a person discontinues exercising in heat conditions for 3-4 weeks period. Then this person has to acclimate himself all over again.

Ideal time for exercising in the summer

If the ambient temperature is above 90°F and the humidity is above 60%, it is better to curtail exercise to protect yourself from injury.

  • According to the heat stress index of The American Council on Exercise, under normal circumstances there is no harm in exposure at a temperature below 80°F (27°C).
  • Fatigue is possible with prolonged exposure at 80–90°F (27–32°C).
  • Heat cramps and exhaustion are possible at 90–105°F (32–41°C).
  • Cramps and exhaustion is likely and  heatstroke is possible 105–130°F (41–54°C).
  • At a temperature over 130°F (54°C) heatstroke is imminent.  

It is better to beat the summer by having the session in the early morning or late in the evening in summer.

Humidity and summer
Sweating cools your body by taking away the heat from your skin during evaporation. When the weather is humid and the air is already near saturated with moisture the sweat remains on the skin as it cannot evaporate. In such a situation the body temperature keeps increasing during exercise and stress may result.

Dress for exercising in the summer
Wear minimal, loose-fitting, lightweight and water absorbing clothing while exercising in summer. Tight-fitting thick clothing impermeable to water will hamper the evaporation of sweat and subsequent cooling of the skin and cause heat injury. Light-colored clothing reflects the sun rays away. Though head helps in cooling the body, it can also increase temperature in sun exposure. If the exercise is outdoor, wear loose-fitting hat to protect yourself from summer sun.

Stay hydrated while exercising in the summer heat

As a daily routine, thirty minutes before start of exercise make sure that you are sufficiently hydrated by taking copious amounts of water. Avoid drinks containing caffeine or alcohol  as they dehydrate you. During the session, for every 15-20 minutes take a break to drink water. At the end of the session drink fluids till the thirsty feeling ceases. If the session extends beyond 60 minutes consider drinking sport drink to replace lost electrolyte salts in the sweat.

Dangerous side effects of overdoing in summer

Hyperthermia denotes a bunch of body-temperature-related illness caused by high temperature of the body. If the body temperature goes beyond 100°F and if the humidity is also high, there is always the danger of hyperthermia. The balance between the heat made by the body and that it loses, goes haywire.

In such a situation a person may suffer heat syncope with symptoms like light-headedness, dizziness and fainting. Resting in a cool place, drinking water and putting legs up may relieve the symptoms.

Some people suffer cramps with raised body temperature in summer. These cramps are painful tightening of muscles of legs, arms or stomach. Resting in a cool place and drinking water may relieve the cramps.

Heat exhaustion shows symptoms like thirsty feeling, dizziness, weakness, nausea and lack of coordination. There may be profuse sweating and the skin may feel cold and sticky. The pulse rate may go up. Stop exercise immediately. Resting in a cool place and taking lots of fluids may correct the condition. If the condition persists take immediate medical help. If immediate action is not taken this may lead to heat stroke.

The symptoms of heat stroke are fainting, confused behavior, dry skin, rapid or slow pulse, staggering and leading to coma. In such a situation immediate hospitalization and medical aid is required. Please remember that it is a life-threatening situation.

To summarize, following the above health tips can keep one safe while exercising daily in the summer heat.

Interesting Daily Health Tips topic:
Daily health tips - Dental sensitivity - What causes sensitive teeth?
Current topic:
Health tips for exercising in the summer heat



References:
1.The American Council on Exercise; www.acefitness.org
2.National Institutes of Health — Heat Illness; www.health.nih.gov/topic/HeatIllness 

Monday, July 9

Dental sensitivity - What causes sensitive teeth?

Soft drinks and health effects > Sensitive teeth - causes

Tooth sensitivity (dentin hypersensitivity) is characterized by short, sharp pain caused from exposed teeth in response to stimuli, typically thermal (hot and cold), evaporation (cold air), tactile, osmotic or chemical (sweet or sour foods). Though teeth sensitivity can affect individuals of any age, it is more common in the age group of 30-40 years. Relatively more women are affected than men. The most affected teeth are canines and premolars of both the upper and lower arches equally.

Exposed dentin is the basic cause of sensitive teeth

To know clearly the causes of sensitivity, we should know the structure of tooth. Tooth consists of upper visible crown region and lower invisible root region inside the gum. A layer of enamel protects the crown region and cementum protects the root region. At the center is the region called pulp having soft tissues, blood vessels and nerves. In between the outer enamel/cementum layer and inner pulp is another layer called dentin. Dentin consists of microscopic dentinal tubules and integrally connected to pulp. The physiological reaction in either dentin or pulp affects the other. Odontoblasts are the major cell components of dentin and pulp. The extensions of odontoblasts called odontoblastic processes extend through the entire thickness of dentin from pulp to enamel and also occupy the dentinal tubules. Inside the dentinal tubules odontoblastic processes are surrounded by dentinal fluid which accounts for nearly 20% of dentin volume. Dentinal fluid is formed from pulp blood supply and is the communication medium between the outer regions of the dentin and pulp.

Tooth sensitivity is due to fluid movement and fluid force inside dentinal tubules. Not all exposed dentin cause sensitive teeth. There are wider dentinal tubules with no smear layers or thinner smear layers in sensitive dentin when compared to non-sensitive dentin. Pain or sensitivity perception is by the activation of dentinal nerve fibers (A-fibres) present on the pulpal wall. The stimuli activating these nerves are, rapid outward flow caused by capillary forces, contraction and outward flow due to cold and hydrodynamic flow caused by sweetness and sourness.

Causes leading to dentin exposure and sensitive teeth

The erosion of enamel and exposure of dentin may be due to a number of causes. Once the protective enamel or cementum are damaged pressure, temperature and other stimuli cause the teeth to become sensitive.

Poor oral hygiene
Poor oral hygiene causes food decay in the mouth and causes plaque and tartar formation on the teeth leading to caries, cavities, gum recession and dentin exposure.

Faulty tooth brushing
Brushing too hard erodes enamel and exposes dentin. Vigorous brushing, excessive forces and use of hard-bristled brush can erode the enamel and cause recession of gum tissue, exposing the underlying dentin .

Cracked or chipped teeth
Cracking and chipping of teeth exposes the dentin and causes bacterial infections.

Diseases of gum and teeth
Certain inflammations and diseases of gum like pyorrhea, gingivitis and periodontal diseases may cause sensitivity by exposing and damaging the dentin.

Erosive agents
Acidic foods like pickles, yogurt, sour tasting fruits and carbonated soft drinks can cause enamel erosion and expose the dentin. Some tooth whitening products and pastes and some mouth-washes can be acidic in nature and erode enamel. Exposure to stomach acids may occur in gastroesophageal reflux disease (GERD) and the enamel may get eroded.

Causes of teeth attrition
Attrition due to grinding of teeth affects teeth structure, initially affecting the enamel and then the underlying dentin. Once past the enamel, attrition can quickly destroy the softer dentin. The most common cause of attrition is bruxism. Normal functional actions like biting and chewing do not erode enamel.

Routine clinical procedures
Clinical procedures like cleaning, crown placement, filling, root canal treatment, orthodontics or restoration can cause temporary sensitivity which may last for 4-5 weeks.

Recent trends in management of tooth sensitivity

Foremost thing in the management of sensitive teeth is good oral hygiene. A soft bristled brush with a small head must be used to keep the gums healthy and prevent gums from recession. Brushing must be done in a small circular movement for each tooth without excessive use of force covering all the surfaces of the tooth. Highly abrasive tooth powder or pastes should not be used.

The sensitivity will persist unless the exposed open tubular apertures are sealed by a smear layer or any other sealant. In the management of sensitivity, the method used should not cause pain or irritation, should not stain the teeth and should be easy in application.
At-home treatments include desensitizing pastes, gels and chewing gums containing fluoride, strontium chloride, potassium citrate or potassium nitrate which have been found effective in the control of sensitivity.
In-office treatments at a clinic include sealants, fillings over the exposed roots and applying fluoride varnishes, sodium monofluorophosphate, fluorosilicates, sodium fluoride, stannous fluoride, potassium oxalate, conventional dentin bonding agents (DBA), hydroxyethyl methacrylate (HEMA), bioglass, calcium silicate cement, lasers, casein phosphopeptide or amorphous calcium phosphate.

By removing the etiological factors and causes and with proper treatment, occurrence and recurrence of sensitivity of teeth can be even prevented.

Topic of interest:
Child hazards - Potential hazards at home
Current topic:
Causes of sensitive teeth



References:
1.Miglani S, Aggarwal V, Ahuja B. Dentin hypersensitivity: Recent trends in management. J Conserv Dent 2010;13:218-24
2.Brännström M. Etiology of dentin hypersensitivity. Proc Finn Dent Soc. 1992;88 Suppl 1:7-13.