european college of sport science

Wednesday, June 24th, 2009
skeletal muscle mass and strength (Herndon et al., 2002). Protein synthesis in skeletal muscle, particularly contractile protein myosin
heavy chain (MyHC), has been found to be a predictor of locomotory function. A reduction of contractile proteins contributes to the decline
muscular strength (Seene et al., 2008). The purpose of the present study was to assess changes in muscle strength from one month to 80
years old age, and find the relations with changes in locomotory function through the life-span.
Methods : Under assessment were persons from one month till 80 years of age. Pediatric assessment techniques were used for physical
examination during the preschool period. Arm and leg strength (1RM), muscle fiber types, cross-section area, myonuclear domain size
and the myosin heavy chain isoform pattern were measured as described earlier (Seene et al., 2008).
Results: Strength development starts at birth in the form of movements in gravitational field. Taking into account that a infant’s head is 2/3
of its total mature size and muscle mass comprises about 20% of the total bwt, these movements have to exert a force of attraction. After
the fourth decade of life, muscle strength slowly begins to decline. Between 30 and 40 years of age, the decline was ~5%, 40 and 50
~14%, 50 and 60 ~16%, 60 and 70 ~26%, and 70 and 80 ~30%. The decrease of muscle strength is accompanied with the decrease of FT
muscle fibers and IIx isoform relative content of MyHC.
Discussion: It is a widely accepted standpoint that the best time for strength development starts from late puberty. In reality, a newborn
infant starts to fight with gravitation at birth and this process is actual strength development. The development of posture control across
the life-span and its integration with locomotory function show dependence on the muscle strength. When balancing, older adults as well
as like young children, use antagonist muscles more often in coactivation with agonist muscles (Woollacott et al., 1986). Muscle weakness
is the main factor in the dysfunction of locomotor acitvity and balance through the life-span. A decline in muscle strength is in good
agreement with the decrease of proportion of FT muscle fibers and IIx MyHC isoforms relative content in skeletal muscle. Locomotory
dysfunction in infants and elderly people is the result of insufficient muscle strength.
References
Henderson L, Schmeissner P, Dudaronek J, et al. (2002). Nature, 419, 808-814. Seene T, Umnova M, Kaasik P, et al. (2008). Skeletal Muscle
Damage and Repair, 173-184. Human Kinetics.
Seene T, Kaasik P, Alev K, et al. (2008). 6th Int Conf on Strength Training, 41-42. NSCA.
Woollacott M, Shumway-Cook A, Nashner L (1986). Int Aging Hum Dev, 23, 97-114.
THE EFFECT OF THREE DIFFERENT TRAINING MODALITIES ON MUSCLE STRENGTH, MUSCLE MASS AND FUNCTIONAL-
ITY, AMONG ELDERLY
ANDERSEN, V., CUMMING, K., KVAMME, N.H., SOLBERG, P., TOMTEN, S.E., HALLÈN, J., RAASTAD, T.
NORWEGIAN SCHOOL OF SPORTS SCIENCES
Introduction: Muscle strength and muscle mass will decrease with age (Melton, III et al., 2000; Doherty et al., 1993). As a consequence it
becomes harder to perform everyday activities (Jette & Branch, 1981). It is well recognised that physical training has the potential to counteract
these changes. However, what kind of training that is optimal for both regaining strength and function is still unclear. The aim of
this study was therefore to compare the effect of three training modalities on muscle strength, muscle mass and functionality.
Methods: A total of 51 elderly men and women (aged 69-88) were randomly divided into three training groups and one control group
(CG). The training groups exercised 3 times pr week for 12 weeks while the CG just continued their normal activity. The training groups
were a resistance training group (RTG) following a progressive resistance program consisting of 8 exercises (3 leg exercises) performed
with one to three 4-12 RM sets, a functional resistance training group (FTG) training 8 exercises simulating movements in everyday activities
(4 leg exercises) performed with one to two 12-15 RM sets and one endurance training group (ETG) which trained Nordic walking,
aerobics and walking. All subjects were tested in 1 RM knee-extension, stair climbing without- with 10kg and 20kg external loading, chair
raise, counter movement jump, maximal gait velocity and body composition with DEXA.
Results: RTG increased performance in knee-extension (mean±SEM:37±4.5%), stair climbing with 10kg (12±3.4%) and chair raise
(9±2.3%). FTG increased performance in knee-extension (29±5.6%), all stair climbing tests (17±2.5%,19±2.1% and 15±2.5%) and chair raise
(12±2.8%). ETG increased performance in knee-extension (24±3.5%) and CG increased performance in knee-extension (16±4.4%) and
stair climbing with 10kg (8±2.2%) and 20kg (6±2.6%). RTG, FTG and ETG all increased lean body mass (respectively 3±0.8, 2±0.5 and
4±0.8%), but only FTG increased total body mass (0.9±0.2%). RTG increased knee-extension performance more than CG, FTG increased
stair climbing performance more than ETG and chair raise performance more than CG. RTG, FTG and ETG increased lean body mass
more than CG.
Discussion: In our study we compared three different training modalities and found that all the training groups increased lean body mass
and muscle strength. In the tests of functionality only the RTG and FTG increased their performance, especially in the stair climbing tests.
Surprisingly the CG also improved their muscle strength and two out of three stair climbing tests. A possible explanation may be that also
the CG increased activity level because they participated in the study. In conclusion the RTG and FTG increases muscle mass, muscle
strength and functionality in a similar manner.
Reference List
Doherty, et al. (1993). Can.J.Appl.Physiol, 18, 331-358.
Jette, & Branch (1981). Am.J.Public Health, 71, 1211-1216.
Melton, et al. (2000). J.Am.Geriatr.Soc., 48, 625-630.
INFLUENCE OF TRAINING FREQUENCY AND ADVANCING AGE ON THE HISTO-MORPHOLOGY OF ADRENAL MEDULLA
IN RATS
VINCENT, S., POULAIN, S., TURLIN, B., LE DOUAIRON-LAHAYE, S., MALARDÉ, L., LEMOINE MOREL, S., CARRÉ, F., ZOUHAL, H.
LABORATOIRE MOUVEMENT SPORT SANTÉ (M2S)
Introduction: Aging induces alterations of sympathoadrenergic system (Zouhal et al. 2008). It could be explained by an increase in the
sympathetic nervous activity with advancing age and/or by a compensatory mechanism related to the fall of the organization sensitivity
to sympathoadrenal stimulation (Mazzeo et al. 1997). It is well known that endurance training induces an increase in adrenal gland (AG)
and adrenal medulla (AM) volume in young rats (Stallknecht et al. 1990). Previous internal study showed that high frequency of endurance
training is more efficient in young rat (Poulain et al. 2008). In old rat, the endurance training frequency efficient to modify the volume of AG
and AM remained to be clarified. The purpose of the present study was to compare the effects of two endurance training programs with
different frequencies (endurance training session per week) on AG and AM in old rats.
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