Skeletal muscle adaptation: training twice every second day versus training once daily

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Abstract from J Appl Physiol. 2004 Sep 10

Skeletal muscle adaptation: training twice every second day versus

training once daily.

Hansen AK, Fischer C, Plomgaard P, Andersen JL, Saltin B, Pedersen BK.

Department of Infectious Diseases, Rigshospital, Copenhagen, Denmark;

The Copenhagen Muscle Research Centre, Rigshospital, Copenhagen,

Denmark.

Low muscle glycogen content has been demonstrated to enhance

transcription of a number of genes involved in training adaptation.

These results made us speculate that training at a low muscle glycogen

content would enhance training adaptation. We therefore performed a

study in which seven healthy untrained males performed one-knee legged

exercise training at a low glycogen (Low) protocol, whereas the other

leg was trained at a high glycogen (High) protocol. Both legs were

trained equally regarding workload and training amount. Day one: Both

legs (Low+High) were trained for 1 hour followed by 2 hours of rest at a

fasting state, where after one leg (Low) was trained for 1 more hour.

Day 2: Only one leg (High) trained for 1 hour. Days 1 and 2 were

repeated for 10 weeks. As an effect of training, the increase in maximal

workload was identical for the two legs. However, time till exhaustion

at 90% was markedly more increased in the Low leg compared with the High

leg. Resting muscle glycogen and the activity of the mitochondrial

enzyme hydroxyacyl CoA dehydrogenase (HAD) increased with training, but

only significantly so in LOW, whereas citrate synthase (CS) activity

increased in both low and high. There was a more pronounced increase in

CS activity when Low was compared with High. In conclusion, the present

study suggests that training twice every second day may be superior to

daily training.