# The Effects of High Resistance Training in Myotonic Dystrophy patients

http://en.wikibooks.org/wiki/Exercise_as_it_relates_to_Disease

## Background

Myotonic Dystrophy is the most common form of Muscular Dystrophy. Characterized by wasting of the muscles and muscle weakness, Myotonic Dystrophy is a genetic disorder that affects approximately 1 in 8000 people worldwide. Myotonic Dystrophy differs from other forms of muscular dystrophies as it is associated with a number of other disorders including myotonia (delayed relaxation of muscles after contraction), endocrine changes , cataracts and heart conduction defects. There are two forms of myotonic dystrophy, including DM1 (type 1) and DM2 (type 2), both inherited but affecting a different gene..

### Symptoms.

Symptoms may occur from birth onwards but as the disease is slow progressing, it isn't usually till adulthood until signs are present. One of the first signs of myotonic dystrophy is muscle stiffness caused from myotonia. Other symptoms may include heart problems, breathing troubles, difficulty swallowing, excessive tiredness and digestive problems. Hormonal problems are also often related to the disease and may include reproductive abnormalities, diabetes and thyroid dysfunction .

### Cause

Myotonic Dystrophy is caused by a genetic mutation of the DMPK gene found on chromosome 19. The DMPK gene contains an area where the three building blocks of DNA, CTG and genetic material are repeated. A normal gene will contain 5-35 repeats CTC repeats but an individual with Myotonic Dystrophy will have anywhere from 50 to 10,000 depending on the severity of the case.

## The effects of high resistance training

* Although their is minimal research surrounding the effect of resistance training in myotonic dystrophy patients. There is evidence to suggest a patient with DM can benefit from resistance training with no side effects.
* A study from the Departments of Neurology and Radiation Physics at the Karolinska Hospital in Stockholm, Sweden illustrated that although Resistance training will have no effect on isokinetic concentric and eccentric torque values, it can increase the muscular strength in patients suffering from myotonic dystrophy.
* The same study found not only can resistance training increase muscular strength it can also prevent atrophy of the muscle and in some cases even promote hypertrophy in type 1 muscle fibers.
* An increase in muscular strength and size in patients with DM means diminishing of symptoms including muscular pain, myotonia and balance, allowing patients to move more freely and improve their overall wellbeing.
* Although high intensity resistance training may benefit some patients, depending on the severity of the disease some patients may have no training potential.

## High Intensity Resistance Training

High intensity resistance training involves the combination of both training for strength and hypertrophy. The following table gives a basic guideline on training protocol.
| Rep Range | Percent of 1 Rep Max | Muscular Changes |
| 1-5 Reps | 85-100% | Strength |
| 9-12 Reps | 70-75% | Hypertrophy |
A high intensity resistance training program involves using this guideline, targeting each muscle group twice a week.

## Further readings

Myotonic dystrophy: Prognosis and managementThe Effects of High Resistance Training in Myotonic Dystrophy patients Effects of High Intensity Resistance Training in Patients with Myotonic Dystrophy Scand J Rehab Med 31: 9–16, 1999

## Reference List

* ↑ Muscular Dystrophy Australia. 2013. MYOTONIC DYSTROPHY . [ONLINE] Available at: http://www.mda.org.au/disorders/dystrophies/myt.asp.
* ↑ Genetic Home Reference. 2010. What is myotonic dystrophy?. [ONLINE] Available at: http://ghr.nlm.nih.gov/condition/myotonic-dystrophy. [Accessed 29 September 14].
* ↑ Muscular Dystrophy Australia. 2013. MYOTONIC DYSTROPHY . [ONLINE] Available at: http://www.mda.org.au/disorders/dystrophies/myt.asp.
* ↑ Up to Date . 2013. Myotonic dystrophy: Prognosis and management. Available at: http://www.uptodate.com/contents/myotonic-dystrophy-prognosis-and-management.
* ↑ Tollba¨ck, A., Eriksson, S., Wredenberg, A., Jenner, G., Vargas, R., Borg, K., and Ansved, T. (1999) EFFECTS OF HIGH RESISTANCE TRAINING IN PATIENTS WITH MYOTONIC DYSTROPHY 31: 9–16
* ↑ Wiles CM, Busse ME, Sampson CM, et al. Falls and stumbles in myotonic dystrophy. J Neurol Neurosurg Psychiatry 2006; 77:393.
* ↑ 18.Voet NB, van der Kooi EL, Riphagen II, et al. Strength training and aerobic exercise training for muscle disease. Cochrane Database Syst Rev 2013; 7:CD003907.