Biomaterial Database

Resistance training in the oldest old: consequences for muscle strength, fiber types, fiber size, and MHC isoforms. 2007

A I Kryger, and J L Andersen

Clinic of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark. akry@dadlnet.dk

Resistance training-related changes in muscle strength, muscle size, fiber type, and myosin heavy chain isoform composition in 11 elderly subjects (age range, 85-97 years) after 12 weeks of heavy resistance training (80% of 1 RM) were examined. Twelve subjects constituted a control group. Resistance training increased isometric knee extensor strength 37% (P<0.05) and isokinetic knee strength 41-47% (P<0.05). Lean-quadriceps cross-sectional area increased 9.8% (P<0.05). Muscle fiber hypertrophy occurred only in the type 2 fibers (22% (P<0.05)). Type 1 fiber-type area percentage decreased [4.0 % (P<0.05)] whereas fiber-type area percentage of type 2a fibers increased [5.9% (P<0.05)]. The relative amount of myosin heavy chain (MHC) I (P<0.05) decreased and the relative amount of MHC IIA increased (P<0.05). No effects in the overall number of capillaries per area was observed, but an increase in the number of capillary contacts in the type 2 fiber pool was observed. Heavy resistance training does have beneficial effects on muscle strength and muscle volume in very old frail humans. Furthermore, an increase in fiber size of the fast muscle fibers and an overall increase in the relative amount of fast MHC IIA can lead not only to a stronger, but maybe more importantly, to a more powerful skeletal muscle.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D003718	Denmark	A country in northern Europe, bordering the Baltic Sea and the North Sea. The capital is Copenhagen.	Faeroe Islands,Faroe Islands
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000369	Aged, 80 and over	Persons 80 years of age and older.	Oldest Old
D014891	Weight Lifting	A sport in which weights are lifted competitively or as an exercise.	Lifting, Weight,Liftings, Weight,Weight Liftings
D018485	Muscle Fibers, Skeletal	Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.	Myocytes, Skeletal,Myotubes,Skeletal Myocytes,Skeletal Muscle Fibers,Fiber, Skeletal Muscle,Fibers, Skeletal Muscle,Muscle Fiber, Skeletal,Myocyte, Skeletal,Myotube,Skeletal Muscle Fiber,Skeletal Myocyte
D018995	Myosin Heavy Chains	The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.	Myosin Heavy Chain,Heavy Chain, Myosin,Heavy Chains, Myosin
D020033	Protein Isoforms	Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.	Isoform,Isoforms,Protein Isoform,Protein Splice Variant,Splice Variants, Protein,Protein Splice Variants,Isoform, Protein,Isoforms, Protein,Splice Variant, Protein,Variant, Protein Splice,Variants, Protein Splice