Tag: aerobic

Don’t Forget Your Back

Most of us spend a large portion of the day hunched forward.  Think about when you are working on the computer, cooking, driving or even relaxing.  Your typical posture during these activities is head and neck forward, shoulders rounded forward, back curved and hips flexed.    When you remain in this position for an extended period of time, the muscles in the front of the body tend to shorten or contract, while the muscles in the back of the body tend to weaken.    This can be a set up for back, neck and shoulder problems and in addition, tends to make you look shorter, heavier and less confident.

Stretching before and after exercise as well as during the day is often overlooked in the rush to “get your workout in”.   Stretching however, has numerous benefits.   According to a study published in the Annals of Physical Medicine and Rehabilitation Medicine in September 2016, by I Fekhfekh, et al, dynamic muscle stretching of the knee musculature actually resulted in an increase strength gain in those muscles.  Interestingly, this study also found a decrease in the postural stability of the knee after stretching.    In English, it appears that stretching helps your to build strength, but may decrease the stability of the muscles you stretch at least temporarily.

In general, stretching helps to improve flexibility, joint range of motion, and usually is helpful for injury prevention.    Stretching helps by increasing blood flow to the muscles stretched.  This increased blood flow carries important nutrients to your muscles to allow for muscle growth and repair.  In addition, the increased blood flow helps to wash away muscle “waste” which leads to decreased soreness and inflammation of the muscle.

If allowed to remain in a contracted position for a prolonged period of time, our muscles will shorten.  For example if you spend a large portion of your day sitting in a chair or driving, the muscles in the front of the hips, your hip flexors will shorten.  These muscles have a direct effect on both your posture and your back health.

 

So what should you do?

It is important to stretch the muscles in the front of the body at least daily.

Exercises that focus on the hip flexors:

-Kneeling hip flexor stretch  – in the position of a lunge, allow your back knee to touch the floor and drive the hip of your front leg forward.  This will stretch the hip flexor of the knee on the floor

–Pigeon stretch – extend your right leg straight back and bring the heel of your left leg underneath your right hip.  Then drive your hips forward towards the ground.  Stretch and repeat on the other side.

– Yoga poses such as: low lunge, crescent lunge, upward facing dog, and revolving side angle pose

 

Stretches that focus on the chest muscles and prevent rounded shoulders:

– Door Frame stretch- stand in a doorway or at the corner of a room with your arms up like you were going to stop traffic.  Line your arms up from the elbow to the hand with the doorframe or in the corners of the wall.   Step towards the door and you should feel a stretch in your chest (pectoralis “pec” muscles) and hold for 20-30 seconds.

– Wall slides – stand with your back to the wall and keep your shoulders against the wall.  Walk forward 1-2 steps and slide your arms up and down the wall and squeeze your shoulder blades together.  You should feel a stretch in your upper chest muscles.

–Shoulder squeeze stretch –  clasp your hands together behind your back and slowly try to lift your hands.  Squeeze your shoulder blades together to stretch out the chest wall.

– Yoga poses include : bridge pose, camel pose, cobra pose and cow face pose

 

Stretches for your neck:

– Chin Tucks (Neck Retraction) – keep your shoulders back and your head in a neutral position (eyes facing forwards, chin level) slowly move your head backwards until you feel a slight stretch in the back of your neck.  Hold for 10-20 seconds and repeat.  If needed you can apply a gentle pressure on your chin with your fingertips to press your chin backwards and deepen the stretch.

Incorporating these exercises into your daily routine will help to prevent shortening of the muscles in the front of the body which leads to poor posture and often pain of the neck and back.  As always, if you are having pain which persists you should be evaluated by a certified health care professional to ensure that these exercises are safe for you.

This week we primarily discussed stretching exercises to prevent muscle contraction, and next week we will discuss the importance of strengthening the back muscles to further combat the issues of a hunched posture.

Aerobic Versus Anaerobic Exercise

There are various types of exercises that affect our bodies differently.  Done in combination, this affords you the most “bang for your buck”.    By changing up the type, frequency, intensity and cardiovascular demand in your exercise regimen on a daily basis, you will have a synergist effect and derive numerous benefits from your exercise.

There are to major classes of exercises with regard to oxygen utilization. Aerobic exercise, exercises that utilize oxygen for energy, and anaerobic exercise, exercises that utilize fuel already present in the muscle for energy.

 

Aerobic exercises:

In this type of exercise, our muscles require the oxygen carried in the blood to be used for energy production.  Our muscles use this oxygen to burn both fat and carbohydrates as fuel.  Fuel can be constantly produced in the presence of oxygen, therefore, aerobic exercise can be sustained for a prolonged period of time. The body reacts accordingly by increasing the heart rate and breathing rate to keep up with the muscle oxygen demand.   Over time with training, our muscles become more efficient at extracting oxygen from the blood stream and thus we become “fitter”.  When this happens, you will notice that you will be able to exercise at a higher intensity without feeling winded or noticing a significant increase in your heart rate.   During aerobic exercise, you should feel slightly out of breath, but be able to carry out a conversation.

Some benefits of aerobic exercise includes: 

  • Improved overall level of fitness
  • Improved mood
  • Possible reduction of
    • Cancer risk
    • Cardiovascular disease
    • Osteoporosis
    • Diabetes
  • Higher level of fat burning (as opposed to anaerobic exercises)
  • Improved bone density (less beneficial then anaerobic exercises)
  • Moderate reduction in blood pressure
  • Decreased insulin resistance
  • Increases likelihood of surviving a heart attack

Anaerobic exercise:

In contrast to aerobic exercise, anaerobic exercise is exercise performed without oxygen.  This type of exercise is performed at a higher level of intensity and can only be sustained for a few moments.  Sprinting and heavy weight lifting are two examples of anaerobic exercise.   Anaerobic exercises utilize the energy that is already present in the muscle tissue.  However, because no oxygen is present to produce more energy, these exercises cannot be sustained once the fuel present in the muscle runs out after about 10-15 seconds.

Some benefits of Anaerobic exercise:

  • Strengthen bones and improves bone density
  • Builds and maintains lean muscle mass
  • Burns fat (though less so then an aerobic exercise)
  • Increases performance in sports by increasing strength, speed and power

A specific type of anaerobic exercise is Plyometric exercise.

Plyometric Exercises:

These types of explosive exercises are known as plyometric exercises (jump training).    This type of exercise uses your own weight and the force of gravity to provide resistance during the exercise.    The reason to incorporate these exercises into our exercise regimen is that plyometric exercise helps to develop explosive power and increase agility.

Without getting too technical, plyometric exercises are based on the muscle stretch reflex.

Whenever a muscle is stretched, a signal is sent to the nervous system that indicates that the muscle has been stretched.  The nervous system processes this signal and stimulates the muscle to contract in response to this stretch.    This is a reflex because the response is instantaneous.  Over time and with training, the fibers in the muscle (fast twitch fibers) become more sensitive to the stretch and maximize the speed and number of motor units that respond to the stretch.  By increases the fiber number and sensitivity, the muscle response becomes more explosive and generates more power.

Numerous studies have demonstrated that plyometric training should start slowly and work up gradually in intensity.  Plyometric training can be general such as jumping, jump squats, jump lunges but can also be more sports specific depending on the activities you would like to improve.    Typically plyometric exercises tend to focus on the lower body and utilize muscles around the knee and hip.    However, the use of medicine balls allow for plyometric activities of the shoulders and arms.

It is very important to warm up properly to increase the flexibility of the muscle and connective tissues around the joints to prevent injury.  It imperative that you slowly add in and increase your plyometric exercises when you feel your body can handle the impact.   For example, start off doing stepping jumping jacks and then gradually add in 1 jumping jack for every 5 stepping jacks.  Over a period of days to weeks, continue to add more jumping jacks and decrease the amount of stepping jacks.  Once you are able to comfortably complete a minute of jumping jacks without any pain or significant shortness of breath, you can start adding in superman jacks.   Again add 1 superman jack for every 5-10 jumping jacks and gradually increase the amount of superman jacks.   Since this is an anaerobic, plyometric exercise, if you are doing them correctly, you will only be able to do about 10-15 seconds of this until you become winded and need to take a break.

Isometric Exercises, Isotonic Exercises, and Isokinetic Exercises

 

Last week we discussed the importance of aerobic and anaerobic training and this week we will focus on the importance of incorporating strength training into your exercise regimen. Basically, there are several different categories of exercise: Isometric Exercises, Isotonic Exercises and Isokinetic Exercises. By combining the first two types of exercises during your weekly workout regimen, you will attain synergistic benefits that both these exercises provide.

One of the main reasons for exercise is for weight loss and to improve your body composition. According to a study done at UCLA School of Medicine by Dr. Srikanthan published in July 2011 in the Journal of Clinical Endocrinology and Metabolism, building higher muscle mass may improve insulin sensitivity and decrease the risk for both pre-diabetes and diabetes. This finding is quite significant because provides motivation for those who have difficulty “losing weight”. By adding resistance (strength training) into your exercise programwe are still building muscle mass and therefore, decreasing our risk for pre-diabetes and diabetes and contributing to positive changes in our metabolic profile. In addition, several studies have demonstrated that strength training may improve our self-esteem and body image more so than aerobic exercises alone.

So what are the different types of exercises we perform?

Isotonic Exercises:
In this type of exercise, thereis no change in the muscle tone or degree of muscle tension throughout the exercise.In simpler terms, during these exercises, the muscle contracts and causes the body part to which it is connected to move. These exercise result in a change in the joint angle that the muscle crosses. A bicep curl results in bending and straightening of the elbow joint. Typically, isotonic exercises are more vigorous types of exercises such as cycling, swimming, running, tennis, etc. In general, isotonic exercises tend to burn more calories, improve bone density and lower risk of heart disease. Isotonic exercises can be further classified by the type of contraction that occurs in the muscle.

Concentric Isotonic Exercises:
In this type of exercise, (i.e. the upward motion of a bicep curl with weights), the force the muscle generates is greater than the resistance placed on the muscle (weight in the hand) leading to a shortening of the muscle. Concentric exercises always decrease the angle of the joint that the muscle crosses. For example, the upward motion of a bicep curl — starting with the arm fully straight with the hand and weight by the thigh and ending when the arm is fully bent with the hand and weight by the shoulder — is the concentric portion of this exercise.

The Benefits of Concentric Exercises Include:

  • Allows for specific muscle strengthening and repair of muscle damage
  • Improvement in the range of motion in the joint and muscles exercised
  • Improvement in strength in the muscle exercised

Eccentric Isotonic Exercises:
Eccentric exercises occur when the muscle is contracting but lengthening at the same time. In this case the force of the weight may be greater than the force that the muscle can generate. Examples of eccentric isotonic exercises include slowly putting down a heavy object, or the downward portion of the bicep curl — beginning with the hand and weight at the shoulder and slowly straightening the arm and elbow and ending with the hand and weight at the thigh. In eccentric exercises the joint angle that the muscle crosses gets larger. Eccentric exercises are the main cause of muscle soreness and are more likely to result in injury. This is because the muscle is contracting but lengthening at the same time which results in more micro-tears in the muscle belly. It is not the tearing of the muscle that builds muscle, but instead the repairing of these muscle tears which increase protein production and causes muscle growth and hypertrophy (swelling or enlargement). Eccentric exercises are thought to provide greater muscle strengthening as compared to concentric exercises because of the higher tension the muscle is under during the exercise.

Exercises such as cycling, swimming, weight lifting (upwards and downwards motion of the weight), and stair climbing all provide benefits of both concentric and eccentric exercise as the muscles are shortening and lengthening throughout the exercise.

In contrast, Isometric Exercises, occur when the muscle contracts but there is no change in the length of the muscle. It neither lengthens nor shortens throughout the exercise. In this case the force generated by the muscle is equal to the opposing force (such as a hand weight). Therefore, neither the muscle nor the joint moves. An example of an isometric exercise is holding a weight out in front of the body in a fixed position, or holding a squat in a fixed position. Isometric exercises can be further divided into:

Yielding Isometric exercises are those in which the weight is neither dropped nor lifted, despite the fact that the muscle has the ability to move the weight.

Overcoming Isometric exercises are those that no matter how much force is exerted by the muscle, the weight will not move. For example, attempting to move a 2000 pound boulder by pushing against it is an overcoming isometric exercise. The terms yielding and overcoming are somewhat of semantics as the benefits of both types are isometric exercises are fairly equal.

Benefits of Isometric Exercises:

  • Can be used in cases of arthritis when joint movement is painful
  • Used to heal injured muscles without much strain being placed on the joints
  • Improves muscle strength and size
  • Less chance of injury when performing these exercises
  • Ability to isolate certain muscles to allow for strength training and muscle healing
  • Increased bone density
  • Increase in lean muscle mass
  • Decreased blood flow during the prolonged muscle contraction may contribute to increased muscle growth because growth factors remain in the muscle tissues longer
  • Holding the contractions longer increases muscle mass
  • Increasing the number of contractions increases muscle strength

Risks/Caveats of Isometric Exercises:

  • Blood pressure rises during contractions which can be risky in individuals with high blood pressure or increased risk of stroke
  • Increases in strength are angle specific therefore it helps to hold the exercise in several positions. For example, an isometric bicep curl should be held with the elbow joint at approximately 45 degrees, 90 degrees and 135 degrees to strengthen different parts of the muscle belly.
  • No improvement in muscle speed, agility or power
  • If body alignment is poor, injury is more likely

Another type of exercise that exists is an Isokinetic Exercise. In this exercise, usually machines are used which control the speed of the muscle contraction within a specific range of motion. Essentially, these machines can control the resistance placed on the muscles and keep the speed of the muscle movement fairly constant. These machines combine the benefits of isotonic and isometric exercises. Examples of these machines include the stationary bicycle, and the Cybex arm machine.

Benefits of Isokinetic Exercise:

  • Used to rehabilitate muscles
  • Uses uniform resistance that adapts to the body
  • Less stressful on the body
  • Increases range of motion without muscle fatigue or muscle strain
  • Muscles are allowed to rest which avoids lactic acid build up

Typically, isokinetic exercises are utilized by Physical therapists and Occupational therapists for rehabilitating muscles after injury, or for treating muscle imbalances which may lead to injury. As with all exercise programs, it is important to start with little to no resistance and build up slowly both your resistance and your repetition count. If you have injuries, you should seek medical attention to determine which exercises are right for you and which can lead to worsening of your injuries.