The benefits of eating a High GI carbohydrate meal after exercise.

When most people hear the word Hi GI food they run for the hills because of the “negative” connotations and how high Gi food is linked with weight gain. BUT there are two important times of day that High Gi carbohydrates can be taken in, the first is with breakfast in the morning because you are coming off a "fast". So, at that time you want a simple carbohydrate source to “re start the metabolism. And the second time of day and the one that will be discussed is straight after exercise.

Firstly what must be understood is what High GI is or High Glycemic foods. The Glycemic Index is a measure of how quickly a food raises blood sugar and hence insulin levels. A high Glycemic carbohydrate source is 70 and above.

The reason that the Hi Gi carbohydrates are critical is because it starts the whole recovery/muscle growth process. Following a hard workout, your body is severely depleted of glycogen and glucose.

During the workout working muscles use glucose (usable energy in the blood) and glycogen (stored energy from the liver and muscles) for energy. As such, there is a point at which blood glucose levels and glycogen levels get so low that intense exercise can't continue. There just isn't enough available energy for your muscles to use.

Once this occurs the hormone cortisol is secreted, this is your body's "stress" hormone and it has very catabolic (catabolism is the process that the break down of molecules into smaller units and release energy)  What cortisol does (being catabolic) is it uses up muscle tissue for protein and convert it into glucose. A process called gluconeogenesis ensues, producing glucose from these amino acids in the liver. The net result is a loss of muscle tissue.

The post-workout meal prevents this. It also allows insulin to be released, one of several anabolic hormones in the body and that is why it is critical to get the carbs to the muscle cells as fast as possible. As well, the elevated insulin levels will help to drive nutrients into the muscle cells and prevent that unwanted muscle breakdown and start the recovery process.

So we see that Hi Gi carbs have their place and it’s all a matter of timing!

What is this infamous rotator cuff?

By Megan Mac Vay

I have often heard people mention that they have or have previously had a “rotator cuff” problem but rarely have these persons actually known or understood what a rotator cuff is or what the injury was to begin with. This may be the result of poor explanation from the practitioner, but most often is as a result of this term being freely used amongst the general public for any sort of shoulder pain or injury.

So today I am going to hopefully clear up any misunderstandings. Your rotator cuff is made up of the muscles and tendons deep within your shoulder joint which connect your upper arm bone (Humerus) with your shoulder blade (Scapula). They also help hold the ball of your humerus firmly in your shoulder socket. The combination results in the

greatest range of motion of any joint in your body and provides an unbelievable strength and stability used in everyday life but most importantly in so many sports (I.e. Bowling in cricket). Therefore, in terms of importance, this area of your body may be considered your most valuable feature.

An injury to your rotator cuff includes any type of irritation or damage to your rotator cuff muscles or the tendons, and as such there are three classifications of an injury associated with it:

• Strain – The tendons stretch but do not tear.
• Partial Tear – There is a partial tear to a tendon but it does not completely sever.
• Full Tear – The tendon or muscle tears completely.

Injuries (of each classification) can result from a multitude of movements, forces, and other factors including:

• Attempting to block/cushion a fall with one’s upper arm.
• Thrusting one’s arm up forcefully against resistance.
• Excessive overhead activity.
• Repetitive trauma.
• Degeneration of muscles (with age or use).
• Lack of blood supply.
• Bone spurs (bone overgrowth).

Injury to this area can leave you with large losses of ability and independence, unless you take the steps necessary to rehabilitate the rotator cuff muscles and/or tendons involved before, during and after dysfunction.

Some causes of injury to your rotator cuff, such as degeneration, may take longer to become evident than others. Despite the differences due to the various causes however, there are some telltale signs that you have incurred an injury.

They are:

• Pain when resting, particularly when lying on the injured arm/shoulder.
• Pain during specific movements, such as lowering or lifting your arm.
• Weakness, difficulty lowering or rotating your arm/shoulder.
• A crackling sensation during certain arm/shoulder movements.
• Difficulty with routine activities such as hair brushing.
• Loss of range of motion.

For minor injuries, you can care for your shoulder at home, with rest, cold packs, and over the counter pain medication. Rest implies that you limit the number of overhead and other straining activities you may normally do. Should you get to the point that the pain does not go away with such care however, you will want and need to see a doctor who may advise physiotherapy or exercise with a Biokineticist.

In conclusion, pain in the shoulder region can often be as a result of an injury to the rotator cuff muscles or tendons but will need to be diagnosed by a medical professional. If you do suspect a minor injury, be careful and respect the joint. Should the pain and disability increase, please find medical assistance as soon as possible so as to avoid further injury to the region.

The Difference Between the Effects of a Sprint vs. a Slow Run on Glucose Levels

Written by: Tanya Bellon, Biokineticist

Exercise uses one of two energy systems, aerobic or anaerobic. A good understanding of these 2 energy systems is critical to understanding the exercise challenges faced by individuals with diabetes.  Furthermore this knowledge will aid people with diabetes to ingest the correct snacks and make appropriate insulin dosage adjustments before during and after exercise.

What is Aerobic exercise?

In aerobic exercise such as jogging or cycling, the body uses oxygen to produce energy.  During these exercises, the muscles use oxygen to convert glucose into usable energy for the body.

Why does aerobic exercise cause Hypoglycaemia?

Aerobic activities increases the blood and oxygen supply to the body, causing an increase in insulin circulation. As the length and intensity of the exercise increases so will the demand for energy. This will make the muscles more insulin sensitive therefore increasing the glucose uptake and lowering blood glucose.

Benefits of Aerobic Exercise for both diabetic and non-diabetic people

·         Strengthens heart and lungs

·         Improves muscle sensitivity reducing glucose levels

·         Reduces blood pressure and cholesterol

What is Anaerobic Exercise?

Anaerobic exercise is short and intense, just think of Brian Habana sprinting 50metres to the try line, or a person doing a gym circuit with rest intervals between exercises. The energy to perform this is created without using oxygen. Energy (glycogen) stored in the muscles and liver is converted into usable energy (glucose).

Most sports involve a combination of aerobic and anaerobic energy systems for example rugby and soccer.

Benefits of Anaerobic Exercise for both diabetic and non-diabetic people

·         Builds muscle

·         Strengthens bones

·         Improves speed and power

·         Increases muscle metabolism

Effect of high intensity anaerobic type exercise on a person with Type 1 diabetes

Glucose levels may spike within twenty minutes of starting to a high intensity anaerobic type activity like squash. This reaction known as “Liver dumping” happens because the liver literally “dumps” large amounts of glucose into the blood stream. Intense exercise can cause an adrenal stress response (“flight or fight”) causing increased glucose allowing one to move rapidly or lift a heavy weight.  Consult your doctor or nurse educator when making insulin dosage adjustments or snack adjustements with this type of activity.

Effects of combining Aerobic and Anaerobic exercise for people with Type II diabetes

Research shows that a combination of aerobic and resistance (Anaerobic) training has far greater benefits than only aerobic or resistance training. Patients who walk on the treadmill and do weight training had a greater improvement in their HbA1c than just walking or weight training alone.

In type 1 diabetes the combination of moderate intensity (aerobic) and high intensity (anaerobic exercise) may prevent hypoglycaemia post exercise because of the adrenal response keeping the blood glucose levels higher after exercise. 

Conclusion and Recommendations

It is recommended that aerobic and anaerobic type exercises are incorporated into an exercise programme. People with Type 2 diabetes will experience improvements in overall glucose control, decreased body fat percentages and reduced coronary heart risk factors.

 People with Type 1 diabetes will also show an improvement in glucose control, lowered coronary risk and lowered body fat percentage if they exercise daily or alternate days.  However they need to monitor their blood glucose response to various exercises and then make changes to insulin and snacks accordingly.  In Type 1 diabetes preventing hypoglycaemia during and after activity will improve long term compliance and enjoyment of exercise.

Before starting any exercise programme it is important to have a medical check up with your doctor  to ensure that you are safe to exercise.

Exercise in the heat

Exercise in the heat

by Mr A. E. Hoosen

As people become more aware of the value of exercise, it is important to understand the safety issues surrounding exercise. As we near the summer months, people want to shed those excess centimetres here and there to look good for the beach. As a result more people take to the road to jog or run and even more are in the gyms. In light of the past week we have had in Gauteng, we shall evaluate how to exercise in the heat.

We must first look at the factors that influence heat; conduction, convection, evaporation, radiation, metabolic heat.  Conduction is the transfer of heat from one body to another via direct contact, convection is the transfer of heat, radiation is the transfer of heat from one body to another via electromagnetic waves and evaporation is heat loss via the change in phase of water from a liquid to a gas. These factors can either positively or negatively alter heat balance and in combination can result in heat gain or heat loss except for evaporation. Evaporation exclusively favours heat loss and thus promotes cooling. In the case of the exercising individual, sweating is the most important means through which we lose heat, as the sweat formed evaporates from the skin cooling the skin. If the sweat drips off the skin, that potential of the sweat to reduce heat is diminished. 

FACT80% of heat lost during exercise is due to evaporation of sweat

Now that we have identified the factors that influence heat, we need to identify how hot is hot? 23°C on a sunny day vs 23°C on a cloudy and windy day. This is why we use the heat index, to level the playing field as the environmental heat is more than just absolute temperature. We need to take into account; radiation (sun), humidity, air velocity (wind) and air temperature readings in combination. This can provide us with the apparent heat of the day. Apparent

Temperature Range                                     Dangers/Precautions at This Range

27°C–32°C                            Exercise can be difficult; enforce rest and hydration

32°C–41°C                            Heat cramps and exhaustion; be extremely cautious

41°C–54°C                            Anticipate heat exhaustion; strictly limit activities

54°C and above                    Setting for heatstroke; seek cool shelter

In order to calculate the apparent temperature one can obtain the current temperature and either dew point temperature or humidity and you can use the online calculator at: http://www.hpc.ncep.noaa.gov/html/heatindex.shtml

How does the body respond to exercise in the heat?

Let us look at the cardiovascular system, the heart pumps blood to the body, and during exercise blood flow is directed to the muscles to meet energy demands, however with exercise the body generates heat and some blood is directed away from the muscles to the skin. This allows the body to dissipate heat via convection, radiation and evaporation. However in the heat the body transfers more blood to the skin to accelerate heat loss in an attempt to keep cool, this results in the heart speeding up the rate of pumping, and results in a phenomenon called cardiovascular drift. Cardiovascular drift is whem heart beats so fast that instead of pumping out more blood, less blood is pumped per beat.

The second means of dissipating heat is through sweat loss. Sweat production draws from the water located in the plasma of the blood. When one exercises for a prolonged period of time without replacing fluids, the blood becomes more viscous, resulting in less blood being able to pass through the body reducing the supply of oxygen and nutrients to the muscle. These two factors can hamper performance and can in combination pose a health risk.

Guidlines to Exercise in the heat:

1.       Exercise in the mornings and evenings.

2.       Drink plenty of fluids even when not thirsty every 15-30minutes (Isotonic replacement)

3.       Clothing

              a. Clothing that allows ventilation

              b. Wear light coloured clothes

              c. Cover small surface area of the body (expose maximum surface area)

              d. Hats for extreme sunlight

4.       Utilise sunblock

5.       Avoid exercise when heat index is 32^oC or more

6.       Avoid consuming salt tablets or foods high in salt

WARNING SIGNS OF HEAT EXHAUSTION

• Heavy sweating
• Fatigue
• Headache
• Pale, clammy skin
• Thirst
• Rapid heartbeat
• Dizziness, fainting
• Nausea, vomiting
• Muscle and abdominal cramps 
• Mild temperature elevations

If one experiences the following conditions, move to a cooler shady area, drink cool liquids and seek medical attention immediately. Now that summer is at the door step we can now exercise safely

20th October – WORLD OSTEOPOROSIS DAY

By Bailey Cockerill

Defⁿ: Osteo – Bone; Porosis – Porous

A porous bone disease resulting in a high risk of bone fracture

Osteoporosis is considered to be one of the most common bone diseases and is easily preventable if you know the do’s and don’ts. Prevention, in this instance is without doubt better than cure!

What Causes Osteoporosis?

Throughout our lives the skeletal structure is continuously being remodeled with old bone tissue being removed (resorbed) and laid down (reformed). Unfortunately the bone reformation process is slowed down the older we get resulting in more resorbtion occurring and less bone density resulting. Once women reach menopause and there is a resultant drop in oestrogen levels, an accelerated bone loss can be noticed. This is not to say that men are not equally at risk as once testosterone levels begin to drop, they too can be at higher risk.

Who is at Risk?

• Females (not that males aren’t though!!)  
  
• Smokers  
  
• Individuals with inadequate caloric intake  
  
•  Inactive individuals
  
• Ammenorrhoeric females (prolonged absence of menstrual cycle usually associated with overly active female athletes) – Balance is key  
  
• Early onset of menopause

Prevention?

Healthy diet with adequate amounts of calcium. Remember that Vitamin D is needed to help absorb calcium – you can’t have one without the other!

Limit smoking, caffeine and alcohol intake as they may lead to increased bone loss. 

Do weight bearing exercises (eg. walking, jogging, resistance exercises etc) Not only does it help with actual bone density, but also improves balance which is imperative in helping prevent falls that can result in serious fractures if already struggling with osteoporosis.

Have regular checks for your bone density. A DEXA scan is the most accurate form of screening.

Other risk factors include a family history of osteoporosis and age associated changes in sex hormones. However these are obviously unavoidable and just need to be taken into consideration.

So, start early with a healthy diet, regular exercise and limit intake of caffeine, alcohol and smoking to keep your bones strong and healthy!

General Exercise Guidelines from the American College of Sports Medicine

by Lauren Williamson

The American College of Sports Medicine (ACSM) recently updated its position stand on the quantity and quality of exercise for healthy adults. For improvement of cardiovascular fitness and body composition, they recommend performing physical activity 3 - 5 times each week for 20 - 60 minutes at a time. That therefore means a minimum of 60 minutes per week of physical activity. Exercise sessions should involve activities that involve large muscle groups (e.g., walking, running, cycling, and swimming).

The intensity level (target heart rate) for this physical activity should be at least 55% - 65% of your maximum heart rate. (You can estimate your maximum heart rate by subtracting your age from 220.) You can quickly determine if your intensity is too high by taking the "talk test"; if you cannot maintain a conversation with your exercise partner while exercising, then your intensity is too high. The ACSM also recommends that you include muscular strength and flexibility training in your exercise program.

If you are not currently exercising, please consult your physician before beginning any exercise program. If you’ve been given the all-clear to exercise, start off at a comfortable training pace and slowly increase your intensity, frequency and duration of training.

REMEMBER! Consistency is the key to success in any exercise program; choose an activity that you enjoy and are likely to continue throughout your adult life.

The Silent Killer

By Nicole Picas

Hypertension, more commonly known as high blood pressure, has been nicknamed ‘the silent killer’ because there are no noticeable symptoms, but its presence can be fatal. An individual with hypertension is at an increased risk for renal (kidney) disease, cardiovascular disease and stroke. The table below classifies blood pressure for adults aged 18 years and older.

Category	Systolic BP (mmHg)	Diastolic BP (mmHg)
Optimal	< 120	< 80
Normal	< 130	< 85
High-normal	130-139	85-89
Hypertension      Stage 1      Stage 2      Stage 3	140-159 160-179 180	90-99 100-109 110

Adapted from ACSM’s Exercise Management for Persons with Chronic Diseases and Disabilities, Second Edition, 2003.

Systolic blood pressure refers to the pressure in the blood vessels when the heart is contracting. Diastolic blood pressure refers to the pressure in the blood vessels when the heart is relaxed. Hence, high blood pressure puts undue strain on the heart. ACSM identifies the following risk factors for hypertension: obesity, high sodium intake, smoking and inactivity. All efforts should be made to modify lifestyle first, but medication may be administered immediately when necessary. It is important to note that hypertension generally does not occur in isolation; often other pathologies exist, such as high cholesterol and insulin resistance.

Exercise plays an important role in managing cardiovascular disease and hypertension by improving cardiovascular fitness, increasing circulation and relieving stress. The following exercise guidelines can be used for persons with hypertension:

·        Increase aerobic activity (walking, jogging, cycling, rowing, etc.) – try to do at least 30-45 minutes 3-5 times per week

·        Avoid heavy weights

·        Avoid movements that involve lifting weights above your head

·        Remember to breathe throughout exercises – don’t hold your breath!

Remember: check your blood pressure on a regular basis so that preventative measures can be taken before the silent killer strikes!