RESEARCH: High intensity exercise is bad for ALS mice

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But low intensity exercise is good!

Effects of high-intensity endurance exercise training

in the G93A mouse model of amyotrophic lateral

sclerosis.

Mahoney DJ, C, Devries M, Yasuda N,

Tarnopolsky MA.

Department of Medical Sciences, McMaster University,

Hamilton, Ontario, Canada.

The G93A transgenic mouse has a mutation in

copper/zinc superoxide dismutase (CuZnSOD) that

results in oxidative stress and motor neuron loss.

Endurance exercise training is known to increase

antioxidant capacity in skeletal muscle. Therefore, we

hypothesized that endurance training may extend onset

of disease or survival in the G93A mouse. We examined

the effects of high-intensity endurance exercise

training (45 min/day, 5 times/week, progressive

increase from 9 to 22 m/min) on disease onset and

survival in G93A mice. Endurance training did not

affect clinical onset, although it hastened death in

male mice (P < 0.05). Endurance-trained males had a

statistically significant decrease in rotarod

performance at 112 days (P < 0.05), whereas sedentary

males decreased at 119 days (P < 0.05).

Endurance-trained and sedentary females decreased at

126 days and 129 days, respectively (P < 0.05). Female

mice lived longer than males (P < 0.05), and there was

a trend for hastened clinical onset in males (P =

0.062). We conclude that high-intensity endurance

exercise training does not affect onset of clinical

symptoms in G93A mice but hastens a decrease in motor

performance and death following onset of clinical

symptoms in male mice only. In light of a recent

report describing increased survival following

low-intensity endurance training, it appears that

training intensity is an important determinant of

survival in the G93A mouse. Copyright 2004 Wiley

Periodicals, Inc.

SOURCE: Muscle Nerve. 2004 May;29(5):656-62.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=1\

5116368 & dopt=Abstract