Thursday, 30 October 2014

High-Intensity Interval Training (HIIT)

 The popularity of HIIT among the general public has increased over the past 5-10 years. This article defines HIIT, and outlines the benefits and exercise recommendations.

What is HIIT?
HIIT describes physical exercise that is characterised by brief, intermittent bouts of vigorous activity, interspersed by periods of rest or low-intensity exercise (Gibala, Little, MacDonald & Hawley, 2012). It refers to exercise training sessions that are relatively brief consisting of ≤10 min of intense exercise within a training session lasting ≤30 min including warm-up, recovery periods between intervals and cool down  such that the total weekly exercise and training time commitment is reduced compared with current public health guidelines (Gillen & Gibala, 2014). Whereas, Moderate Intensity Continuous Training (MICT) refers to physical exercise performed in a continuous, steady-state manner for a prolonged period of time (>30 minutes).

Why use HIIT over MICT?  
Recent evidence from relatively small, short-term studies suggests that HIIT may be as effective as traditional MICT to induce physiological remodelling, which in turn may be associated with improved health markers, despite a reduced time commitment (Gillen & Gibala, 2014). HIIT induces similar or superior improvements in cardiorespiratory fitness (CRF) compared to MICT in sedentary individuals (Tjønna et al., 2013; Gibala et al., 2012) and a number of clinical populations (CVD, lifestyle-induced cardiometabolic disease and obese individuals) (Guiraud et al., 2012; Weston, Wisløff & Coombes, 2014). This is important, as CRF is a strong predictor of mortality (Blair et al., 1996). Moreover, recent evidence suggests that HIIT is perceived to be more enjoyable than MICT (Bartlett et al. 2011).

A recent meta-analysis has identified that HIIT has more physiological benefits (blood pressure, blood lipids, insulin sensitivity, glycaemic control and endothelial function) than MICT in patients with lifestyle-induced cardiometabolic disease. Including HIIT in a training programme implies that greater health-enhancing benefits could be gained in less time, making HIIT a more time efficient and attractive option (Weston et al., 2014).

Protocol Recommendations for HIIT
Frequency
3 x/week
Modality
Cycling, running, stair climbing, uphill brisk walking
Intensity
A maximal sustainable workload for the prescribed duration or interval (unable to maintain a conversation uninterrupted).
Duration
30 min/session
Interval times
10 x 1 min*
1 min recovery
Warm-up/cool-down
5 min @ low-intensity

* Longer duration intervals can also be undertaken (i.e. 1-4 minutes).
You may decide to incorporate one HIIT session per week in combination with MICT. For optimal health benefits, it is recommended resistance and flexibility programs be performed in conjunction with a cardiovascular program. Little is known about the chronic (long-term) effects of HIIT (Gillen & Gibala, 2014).

Exercise Precautions
As with the initiation of any new exercise program, it is important to undergo proper screening procedures (Gillen & Gibala, 2014). HIIT may require initial supervision in untrained and high-risk individuals (Kessler et al., 2012). It may also be prudent to include a preconditioning phase of training consisting of traditional MICT prior to initiating HIIT (e.g. 20–30 min per session, a few times per week for several weeks) to avoid excessive orthopaedic stress (American College of Sports Medicine, 2014). It has been shown that a baseline level of fitness is a cardioprotectant and reduces the risks associated with exercise-induced ischemic events (Thompson et al. 2007).

References
American College of Sports Medicine. (2014). ACSM’s guidelines for exercise testing and prescription (9th ed.). Baltimore, MD & Philadelphia, PA: Lippincott Williams & Wilkins.

Australian Bureau of Statistics 2011-2012. Physical activity and health. http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-active-evidence.htm

Bartlett, J. D., Close, G.L., MacLaren, D.P., Gregson, W., Drust, B., & Morton, J. P. (2011). High-intensity interval running is perceived to be more enjoyable than moderate-intensity
continuous exercise: implications for exercise adherence. Journal of Sport Sciences, 29, 547–553. doi: 10.1080/02640414.2010.545427

Blair, S. N., Kampert, J. B., Kohl, H. W., Barlow, C. E., Macera, C. A., Paffenbarger, R. S. & Gibbons, L. W. (1996). Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women. JAMA, 276(3), 205–210.

Buchheit, M. & Laursen, P. B. (2013). High-intensity interval training, solutions to the programming puzzle part II: anaerobic energy, neuromuscular load and practical applications. Sports Medicine, 43, 927–954. doi: 10.1007/s40279-013-0066-5

Gibala, M. J., Little, J. P., MacDonald, M. J., & Hawley, J. A. (2012). Physiological adaptations to low-volume, high-intensity interval training in health and disease. Journal of Physiology, 590(5), 1077–1084. doi: 10.1113/jphysiol.2011.224725

Gillen, J. B., & Gibala, M. J. (2014). Is high-intensity interval training a time-efficient exercise
strategy to improve health and fitness? Applied Physiology, Nutrition and Metabolism, 39, 409–412. doi: 10.1139/apnm-2013-0187

Guiraud, T., Nigam, A., Gremeaux, V., Meyer, P., Juneau, M., & Bosquet, L. (2012). High-intensity interval training in cardiac rehabilitation. Sports Medicine, 42(7), 587-605. doi: 10.2165/11631910-000000000-00000

Kessler, H. S., Sisson, S. B., & Short, K. R. (2012). The potential for high-intensity interval training to reduce cardiometabolic disease risk. Sports Medicine, 42(6), 489-509. doi: 10.2165/11630910-000000000-00000

Strasser, B. (2013). Physical activity in obesity and metabolic syndrome. Annals of the New York Academy of Sciences, 1281, 141-159. doi: 10.1111/j.1749-6632.2012.06785.x
Thompson, P. D., Franklin, B.A., Balady, G. J., Blair, S. N., Corrado, D., Estes, N. A. M., … 

Costa, F. (2007). Exercise and acute cardiovascular events placing the risks into perspective: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism and the Council on Clinical Cardiology. Circulation, 115(17), 2358–2368. doi:10.1161/CIRCULATIONAHA.107.181485

Tjønna, A. E., Leinan, I. M., Bartnes, A. T., Jenssen, B. M., Gibala, M. J., Winett, R. A., Wisløff, U. (2013). Low- and high-volume of intensive endurance training significantly improves maximal oxygen uptake after 10-weeks of training in healthy men. PLoS ONE 8(5), e65382. doi: 10.1371/journal.pone.0065382

Trost, S.G., Owen, N., Baurman, A.E., Sallis, J.F., & Brown, W. (2002). Correlates of adults’ participation in physical activity: review and update. Medicine and Science in Sport and Exercise, 34(12), 1996–2001. doi: 10.1097/00005768-200212000-00020

Weston, K. S., Wisløff, U., & Coombes, J. S. (2014). High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: a systematic review and meta-analysis. British Journal of Sports Medicine, 48, 1227-1234. doi: 10.1136/bjsports-2013-092576



Monday, 25 August 2014

Piriformis Syndrome and Tethering and the Role of Exercise Physiology


Piriformis syndrome (PS) can best be described as sciatica caused from compression of the sciatic nerve by the piriformis muscle [1]. Tethering of the sciatic nerve may also occur around the tendon of the piriformis muscle (PM) which can also cause irritation. Due to the close proximity of the two structures, an inflamed or spastic PM will cause irritation to the sciatic nerve.
Piriformis syndrome can be identified by 5 salient characteristics; 1) a history of local trauma; 2) pain localised to the sacroiliac joint, greater sciatic notch, and piriformis muscle, which extends along the course of the sciatic nerve and presents difficulty when walking; 3) acute pain brought on by stooping or lifting and somewhat relieved by traction; 4) Palpable spindle mass at the location of the piriformis muscle; 5) a positive Lasegue’s sign [2]. Although difficult to substantiate, the incidence of piriformis syndrome is estimated at about 6-8% of low back pain[2]. 

Diagnosis and Examination 

Although PS only has a low occurrence amongst low back pain mechanisms, it is often underdiagnosed and mistaken for more common conditions such as facet arthropathy, sacroiliitis, lumbar disk disease, or radiculopathy [3]. Therefore, diagnosis of the disease is usually performed by a method of exclusion. A clinician will shoulder initially eliminate a aforementioned mistaken courses of pain, before proceeding to history and physical examinations.

A patient will need to provide a history, detailing sites of pain occurrence, actions which aggravate pain, and actions which may elevate pain. Some common symptoms of PS are pain in buttock with radiation down the posterior thigh, aggravation through sitting or walking [3].

These questions may be asked by a general practitioner, exercise physiologist, physiotherapist, or other clinicians involved in the diagnostic process.

This process will be followed by a physical examination which is commonly performed by a physiotherapist or exercise physiologist. Palpation of the greater sciatic notch may cause tenderness to the site, or radiation down the leg with trigger pointing of the piriformis muscle. The clinician may perform manoeuvres such as the Freiberg’s manoeuvre (see figure 2) or the Pace manoeuvre (see figure 3). A patient may also be referred for further investigation by MRI, CT, ultrasound or EMG as a method of excluding other conditions rather than an official diagnosis.

Exercise Therapy as Treatment 


Piriformis syndrome is a disorder which can be managed or reversed if addressed correctly by using methods which are often individualised depending on the underlying mechanisms which caused the initial syndrome. This process often involves an accredited exercise physiologist (AEP) whose role is to work as a part of a team to determine the underlying mechanisms and facilitate their improvement to reduce the disorders symptoms.

An exercise physiologist’s primary focus is the development of an individualised exercise program to retrain movement patterns to incorporate the correct musculature to facilitate the movement, strengthen the skeletal muscle to improve functional capacity of specific movements, and reduce symptoms of piriformis syndrome by means of trigger pointing or passive assisted stretching.

An outline program commonly encountered in the improvement of piriformis syndrome include exercises to strengthen the hip abductors, extensors, and external rotators, as well as movement re-education to activate appropriate musculature to cause the movement [3]. A program may be broken into phases to appropriately progress individuals through simple isolated movements to final stage dynamic movement patterns. This ensures the individual gains a thorough understanding of muscle activation and the difference between correct and incorrect anatomical positioning.

An example of a program outline may include: phase 1) isolated muscle recruitment exercises such as side lying clams or bilateral bridges; phase 2) weight bearing strengthening exercises, beginning with bilateral movement and progressing into unilateral movements, with exercises including bilateral air squat progressed into single leg sit backs; phase 3) functional training exercises forward and lateral lunges, and bilateral and unilateral squat jumps.

A patient progresses through the phases when the practicing exercise physiologist deems appropriate joint stability and muscle recruitment is occurring [3]. This transition should only proceed if an individual also understands or can ‘feel’ the difference in appropriate and inappropriate muscle recruitment. It is the role of an exercise physiologist to also regress exercises if needed, to allow the individual to gain a thorough understanding of movement patterns.

During the rehabilitation process an exercise physiologist will be tracking a range of different factors which may be affected by your current disorder. These may include ability to perform activities of daily living, psychosocial status, pain levels, or even sleeping patterns. These measures play an important role in the management of an individual’s quality of life (QoL) while suffering from piriformis syndrome. If a exercise physiologist can recognise factors which may be affecting an individual’s QoL, they can implement interventions to combat the said factor, or refer onto an appropriate allied health professional for further treatment.

How do you see an Accredited Exercise Physiologist 


Individuals may be referred to an exercise physiologists by their GP or other allied health practitioners, or book an appointment themselves. If referred patients may be eligible for a medicare rebate. Individuals who have private health insurance may also be able to claim rebates. To find a local AEP or find out more information about an AEP’s role, visit the Exercise and Sport Science Australia (ESSA) website at http://www.essa.org.au/

Reference List

Fishman, L. M., Dombi, G. W., Michaelsen, C., Ringel, S., Rozburch, J., Rosner, B., et al. (2002). Piriformis Syndrome: Diagnosis, Treatment, and Outcome - a 10-Year Study. Archives of Physical Medicine Rehabilitation , 83, 295-301.

Tonley, J. C., Yun, S. M., Kochevar, R. J., Dye, J. A., Farrokhi, S., & Powers, C. M. (2010). Treatment of an Individual With Piriformis Syndrome Focusing on Hip Muscle Strengthening and Movement Reeducation: A Case Report. Journal of Orthopaedic & Sports Physical Therapy , 40 (2), 103-111.

Wetchateng, T. (2013). Piriformis syndrome: Does it bother your daily life? Thammast Medical Journal , 13 (2), 237-242.

Written by Exercise Physiology Brisbane Prac Student: Riley Gould (Charles Sturt Universty).

Saturday, 29 March 2014

It's been a while….


It's been a long time between blogs! After a trip away snowboarding in Japan, followed by a trek up Mt. Kinabalu in Borneo, it's now time to get stuck back into work!!

We'd like to take this opportunity to welcome Todd on board to our team. Todd was a great support whilst we were away having fun and we look forward to working with him more.

How did you all go over Christmas? Make any goals for this coming year?

After a less than impressive Mooloolaba triathlon time two weeks ago, my goal is to improve my swimming and bike strength before Noosa - plenty of time to train and get prepared. ….

Since our last post, the new Australian Physical Activity Guidelines have been released. There have been some slight changes. The new guidelines are outlined below:

The new guidelines are for adults aged 18-64 years, irrespective of cultural background, gender or ability. 

Doing any physical activity is better than doing none. If you currently do no physical activity, start by doing some, and gradually build up to the recommended amount.
Be active on most, preferably all, days every week. 

Accumulate 150 to 300 minutes (21/2 to 5 hours) of moderate intensity physical activity or 75 to 150 minutes (1.25 to 2.5 hours) of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week. 

Do muscle strengthening activities on at least 2 days each week. 

Sedentary Behaviour Guidelines
  • Minimise the amount of time spent in prolonged sitting. 
  • Break up long periods of sitting as often as possible. 
If you'd like to see the guidelines for children and other age groups, click here
How do you compare? Are you meeting these guidelines?

With Easter fast approaching (how quickly did those hot cross buns come out into the supermarkets!!), courtesy of the Heart Foundation, we thought this would be a timely reminder about how much physical activity is required to burn those delicious treats. 

Did you know it takes 40 minutes of walking to burn 6 mini eggs and 2 hours of walking to burn a whole bunny?

Why not try some other fun activities over the Easter break? A great way to burn off some of that chocolate! Click here for more information on how you can burn some extra calories. Everything in moderation of course but if one does indulge, slightly more than the recommended physical activity guidelines will be required….
Speaking of the new physical activity guidelines and burning off excess chocolate, did anyone get a physical activity tracker for Christmas? If anyone got a 'Fit Bit', remember to 'friend' me via the Fit Bit website and we can track and motivate each other to move more throughout the day!

Also, if you haven't signed on for our newsletter, do so now…...
Until next time, stay well and active!

The EPB Team