Ten patients with type 2 diabetes and seven controls were strength-trained with one leg for 30 min three times per week for 6 weeks. The training-induced changes in the protein densities of the Na,K-pump subunits and the Na+/H+ exchanger protein NHE1 were quantified with Western blotting of needle biopsy material obtained from trained and untrained legs of both groups. Training increased the bench press and knee-extensor force by 77+/-15 and 28+/-1%, respectively, in the control subjects, and by 75+/-7 and 42+/-8%, respectively, in the diabetics. In the control subjects the Na,K-pump isoform alpha1 was increased by 37% (P<0.05) in trained compared to untrained leg, and in the diabetics the alpha1 content was 45% higher (P=0.052) in trained compared to untrained leg. For the alpha2 isoform the corresponding values were 21% and 41% (P<0.05), respectively. The content of the beta1 subunit in the control subjects was 33% higher (P<0.05) in trained compared to untrained leg, and 47% higher (P=0.06) in trained compared to untrained leg in the diabetics. Thus, a limited amount of strength-training is able to increase the Na,K-pump subunit and isoform content both in controls and in patients with type 2 diabetes.