The aim of this study was investigate the effects of different intrasession exercise orders in the neuromuscular adaptations induced by concurrent training in elderly. Twenty-six healthy elderly men (64.7 ± 4.1 years), were placed into two concurrent training groups: strength prior to (SE, n = 13) or after (ES, n = 13) endurance training. Subjects trained strength and endurance training during 12 weeks, three times per week performing both exercise types in the same training session. Upper and lower body one maximum repetition test (1RM) and lower-body isometric peak torque (PTiso) and rate of force development were evaluated as strength parameters. Upper and lower body muscle thickness (MT) was determined by ultrasonography. Lower-body maximal surface electromyographic activity of vastus lateralis and rectus femoris muscles (maximal electromyographic (EMG) amplitude) and neuromuscular economy (normalized EMG at 50 % of pretraining PTiso) were determined. Both SE and ES groups increased the upper- and lower-body 1RM, but the lower-body 1RM increases observed in the SE was higher than ES (35.1 ± 12.8 vs. 21.9 ± 10.6 %, respectively; P < 0.01). Both SE and ES showed MT increases in all muscles evaluated, with no differences between groups. In addition, there were increases in the maximal EMG and neuromuscular economy of vastus lateralis in both SE and ES, but the neuromuscular economy of rectus femoris was improved only in SE (P < 0.001). Performing strength prior to endurance exercise during concurrent training resulted in greater lower-body strength gains as well as greater changes in the neuromuscular economy (rectus femoris) in elderly.

Strength training seems to be an interesting approach to counteract decreases that affect knee extensor strength, muscle mass and muscle quality (force per unit of muscle mass) associated with ageing. However, there is no consensus regarding the changes in muscle mass and their contribution to strength during periods of training and detraining in the elderly. Therefore, this study aimed at verifying the behaviour of knee extensor muscle strength, muscle volume and muscle quality in elderly women in response to a 12-week strength training programme followed by a similar period of detraining. Statistical analysis showed no effect of time on muscle quality. However, strength and muscle volume increased from baseline to post-training (33 and 26 %, respectively). After detraining, the knee extensor strength remained 12 % superior to the baseline values, while the gains in muscle mass were almost completely lost. In conclusion, strength gains and losses due to strength training and detraining, respectively, could not be exclusively associated with muscle mass increases. Training-induced strength gains were partially maintained after 3 months of detraining in elderly subjects.

Achilles tendon material properties already improved after 4 weeks of high-load training: stiffness increased while CSA remained unchanged. Tendon hypertrophy (increased CSA) was observed after 8 training weeks and contributed to a further increase in Achilles tendon stiffness, but tendon stiffness increases were mostly caused by adaptations in tissue properties.

The aim was to investigate the effects of the intra-session exercise order during water-based concurrent training on the neuromuscular adaptations in young women. 26 women (25.1±2.9 years) were placed into 2 groups: resistance prior to (RA) or after (AR) aerobic training. Subjects performed resistance (sets at maximal effort) and aerobic training (exercises at heart rate corresponding to the second ventilatory threshold) twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexion) and lower-body (knee extension) one-repetition maximum test (1RM) and peak torque (PT) were evaluated. The muscle thickness (MT) of upper (sum of MT of biceps brachii and brachialis) and lower-body (sum of MT of vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) was determined by ultrasonography. Moreover, the maximal electromyographic activity (EMG) of upper (biceps brachii) and lower-body (sum of EMG of vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (43.58±14.00 vs. 27.01±18.05%). RA and AR showed MT increases in all muscles evaluated, while the lower-body MT increases observed in the RA were also greater than AR (10.24±3.11 vs. 5.76±1.88%). There were increases in the maximal EMG of upper and lower-body in both RA and AR, with no differences between groups. Performing resistance prior to aerobic exercise during water-based concurrent training seems to optimize the lower-body strength and hypertrophy.

Knee osteoarthritis (OA) is associated with quadriceps atrophy and weakness, so muscle strengthening is an important point in the rehabilitation process. Since pain and joint stiffness make it often difficult to use conventional strength exercises, neuromuscular electrical stimulation (NMES) may be an alternative approach for these patients. This study was aimed at (1) identifying the associations of knee OA with quadriceps muscle architecture and strength, and (2) quantifying the effects of a NMES training program on these parameters. In phase 1, 20 women with knee OA were compared with 10 healthy female, asymptomatic, age-matched control subjects. In phase 2, 12 OA patients performed an 8-week NMES strength training program. OA patients presented smaller vastus lateralis thickness (11.9 mm) and fascicle length (20.5%) than healthy subjects (14.1 mm; 24.5%), and also had a 23% smaller knee extensor torque compared to the control group. NMES training increased vastus lateralis thickness (from 12.6 to 14.2 mm) and fascicle length (from 19.6% to 24.6%). Additionally, NMES training increased the knee extensor torque by 8% and reduced joint pain, stiffness, and functional limitation. In conclusion, OA patients have decreased strength, muscle thickness, and fascicle length in the knee extensor musculature compared to control subjects. NMES training appears to offset the changes in quadriceps structure and function, as well as improve the health status in patients with knee OA. Keywords: osteoarthritis; muscle architecture; muscle strength; WOMAC; electrical stimulation Osteoarthritis (OA) is one of the major degenerative diseases and it affects elderly women more frequently than elderly men.1,2 The prevalence of OA is expected to increase dramatically in the near future due to the increased life expectancy and an increasing rate of obesity of the world population.3 The knee is the most affected joint with 13.6% of women above 60 years showing radiographic evidence of OA and/or clinical symptoms. 2OA causes erosion of articular cartilage, weakening of subchondral bone, meniscal degeneration, inflammation of the synovium, and intra-articular osteophytes. 4 These changes lead to a reduction in the range of motion, and increase in joint stiffness and pain. 5In addition to the effects on the joint structure and function, OA also has a negative effect on the musculoskeletal system. Patients with knee OA have decreased knee extensor strength compared to healthy subjects 6-10 and compared to the healthy contralateral limb.11,12 Evidence also suggests that the muscle weakness is associated with a decrease in muscle mass. 11,12However, although a reduction in muscle thickness 11 and anatomical cross-sectional area 12 have been described in OA patients, we were unable to find evidence on how muscle weakness was related to changes in other muscle architecture parameters associated with strength, such as fascicle length, and pennation angle.Fascicle length is related to the number of sarcomeres aligned in series in the ...

INTRODUÇÃO: O nível de atividade física pode interferir na capacidade funcional, influenciando na saúde e qualidade de vida dos idosos. OBJETIVO: Comparar os níveis de atividade física e qualidade de vida entre idosos que praticam exercícios físicos regulares e idosos sedentários, e verificar a associação entre o nível de atividade física e a qualidade de vida nos grupos. MÉTODOS: Foram avaliados 50 idosos do sexo feminino (n= 34) e masculino (n= 16), com idade de 70,24±8,8 anos, divididos em dois grupos - sedentários (G1, n=25) e praticantes de exercícios físicos regulares (G2, n=25). Realizou-se entrevista individual, aplicando-se Anamnese; Questionário Internacional de Atividade Física (IPAQ) e Perfil de Saúde de Nottingham (PSN). A normalidade dos dados foi testada por meio do teste de Shapiro-Wilk, utilizando-se ainda os testes U de Mann-Whitney (qualidade de vida) e Qui-Quadrado (nível de atividade física). A associação entre o nível de atividade física e a qualidade de vida foi avaliada por meio do teste ETA² (p<0,05). RESULTADOS: Em relação ao PSN, o G1 apresentou reduzida qualidade de vida, comparado ao G2. Já para o IPAQ, somente o G1 apresentou diferença significativa (p=0,00) em relação ao G2. Além disso, para o G1, 50% do nível de atividade física foram associados à qualidade de vida, enquanto o G2 apresentou 64%. CONCLUSÕES: De acordo com os resultados encontrados no presente estudo, idosos praticantes de exercícios físicos e idosos sedentários apresentam bom nível de atividade física. Entretanto, idosos praticantes de exercícios regulares possuem maior nível de atividade física, explicando a melhor qualidade de vida neste grupo.

It is unclear if applying larger or more symmetrical pedal forces leads to better performance in cycling. The aims of this study were to assess the relationship between pedal force production and performance in a cycling time trial and to evaluate the relationship between asymmetries in pedal force production and performance. Fifteen competitive cyclists/triathletes performed a 20 km cycling time trial on a cycle trainer while bilateral forces applied to the pedals were recorded along with total time. Total forces applied to the pedals were computed and converted into dominant and non-dominant forces using a leg preference inventory. Pedal force asymmetries ranged from 43% (in favour of the dominant limb) to 34% (in favour of the non-dominant limb). The relationship between total pedal force (averaged from both pedals) and performance time was small (r=-.32, effect size=.66) as well as the association between the asymmetry indices and performance time (r=.01, effect size=.06). In conclusion, applying large forces on the pedals and balancing pedal force application between the dominant and non-dominant limbs did not lead to better performance in this cycling time trial.

BackgroundEccentric exercises have been used in physical training, injury prevention, and rehabilitation programs. The systematic use of eccentric training promotes specific morphological adaptations on skeletal muscles. However, synergistic muscles, such as the triceps surae components, might display different structural adaptations due to differences in architecture, function, and load sharing. Therefore, the purpose of this study was to determine the effects of an eccentric training program on the triceps surae (GM, gastrocnemius medialis; GL, gastrocnemius lateralis; and SO, soleus) muscle architecture.MethodsTwenty healthy male subjects (26 ± 4 years) underwent a 4-week control period followed by a 12-week eccentric training program. Muscle architecture [fascicle length (FL), pennation angle (PA), and muscle thickness (MT)] of GM, GL, and SO was evaluated every 4 weeks by ultrasonography.ResultsFascicle lengths (GM: 13.2%; GL: 8.8%; SO: 21%) and ML increased (GM: 14.9%; GL: 15.3%; SO: 19.1%) from pre- to post-training, whereas PAs remained similar. GM and SO FL and MT increased up to the 8th training week, whereas GL, FL increased up to the 4th week. SO displayed the highest, and GL the smallest gains in FL post-training.ConclusionAll three synergistic plantar flexor muscles increased FL and MT with eccentric training. MT increased similarly among the synergistic muscles, while the muscle with the shortest FL at baseline (SO) showed the greatest increase in FL.