Photobiomodulation increases mitochondrial citrate synthase activity in rats submitted to aerobic training.

This study investigated the effects of photobiomodulation by low-laser laser therapy (LLLT) on the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and the anaerobic threshold (AT) in rats submitted to treadmill exercise. Fifty-four rats were allocated into four groups: rest control (RCG), rest laser (RLG), exercise control (ECG), and exercise laser (ELG). The infrared LLLT was applied daily on the quadriceps, gluteus maximum, soleus, and tibialis anterior muscles. Muscle samples (soleus, tibialis anterior, and cardiac muscles) were removed 48 h after the last exercise session for spectrophotometric analysis of the CS and LDH. The CS activity (µmol/protein) in ELG (16.02 and 0.49) was significantly greater (P < 0.05) than RCG (2.34 and 0.24), RLG (6.25 and 0.17), and ECG (6.76 and 0.26) in the cardiac and soleus muscles, respectively. The LDH activity (in 1 Mm/protein) in soleus muscle was smaller (P < 0.05) for ELG (0.33) compared to ECG (0.97), RLG (0.79), and RCG (1.07). For cardiac muscle, the LDH activity was smaller (P < 0.05) in ELG (1.38) compared to ECG (1.91) and RCG (2.55). The ECG and ELG showed increases in the maximum speed and a shift of the AT to higher effort levels after the training period, but no differences occurred between the exercised groups. In conclusion, the aerobic treadmill training combined with LLLT promotes an increase of oxidative capacity in this rat model, mainly in muscles with greater aerobic capacity.

Effects of low-level laser therapy (808 nm) on isokinetic muscle performance of young women submitted to endurance training: a randomized controlled clinical trial.

Low-level laser therapy (LLLT) has shown efficacy in muscle bioenergetic activation and its effects could influence the mechanical performance of this tissue during physical exercise. This study tested whether endurance training associated with LLLT could increase human muscle performance in isokinetic dynamometry when compared to the same training without LLLT. The primary objective was to determine the fatigue index of the knee extensor muscles (FIext) and the secondary objective was to determine the total work of the knee extensor muscles (TWext). Included in the study were 45 clinically healthy women (21 ± 1.78 years old) who were randomly distributed into three groups: CG (control group), TG (training group) and TLG (training with LLLT group). The training for the TG and TLG groups involved cycle ergometer exercise with load applied to the ventilatory threshold (VT) for 9 consecutive weeks. Immediately after each training session, LLLT was applied to the femoral quadriceps muscle of both lower limbs of the TLG subjects using an infrared laser device (808 nm) with six 60-mW diodes with an energy of 0.6 J per diode and a total energy applied to each limb of 18 J. VT was determined by ergospirometry during an incremental exercise test and muscle performance was evaluated using an isokinetic dynamometer at 240°/s. Only the TLG showed a decrease in FIext in the nondominant lower limb (P = 0.016) and the dominant lower limb (P = 0.006). Both the TLG and the TG showed an increase in TWext in the nondominant lower limb (P < 0.001 and P = 0.011, respectively) and in the dominant lower limb (P < 0.000 and P < 0.000, respectively). The CG showed no reduction in FIext or TWext in either lower limb. The results suggest that an endurance training program combined with LLLT leads to a greater reduction in fatigue than an endurance training program without LLLT. This is relevant to everyone involved in sport and rehabilitation.

Effects of low level laser therapy (808 nm) on physical strength training in humans.

Recent studies have investigated whether low level laser therapy (LLLT) can optimize human muscle performance in physical exercise. This study tested the effect of LLLT on muscle performance in physical strength training in humans compared with strength training only. The study involved 36 men (20.8±2.2 years old), clinically healthy, with a beginner and/or moderate physical activity training pattern. The subjects were randomly distributed into three groups: TLG (training with LLLT), TG (training only) and CG (control). The training for TG and TLG subjects involved the leg-press exercise with a load equal to 80% of one repetition maximum (1RM) in the leg-press test over 12 consecutive weeks. The LLLT was applied to the quadriceps muscle of both lower limbs of the TLG subjects immediately after the end of each training session. Using an infrared laser device (808 nm) with six diodes of 60 mW each a total energy of 50.4 J of LLLT was administered over 140 s. Muscle strength was assessed using the 1RM leg-press test and the isokinetic dynamometer test. The muscle volume of the thigh of the dominant limb was assessed by thigh perimetry. The TLG subjects showed an increase of 55% in the 1RM leg-press test, which was significantly higher than the increases in the TG subjects (26%, P = 0.033) and in the CG subjects (0.27%, P < 0.001). The TLG was the only group to show an increase in muscle performance in the isokinetic dynamometry test compared with baseline. The increases in thigh perimeter in the TLG subjects and TG subjects were not significantly different (4.52% and 2.75%, respectively; P = 0.775). Strength training associated with LLLT can increase muscle performance compared with strength training only.

Isoflavone-supplemented soy yoghurt associated with resistive physical exercise increase bone mineral density of ovariectomized rats.

OBJECTIVE: To determine the effects produced by the ingestion of a fermented soy product (soy yoghurt), supplemented with isoflavones and associated with a resistive exercise program, on the bone metabolism of mature ovariectomized (Ovx) and sham-ovariectomized (sham-Ovx) rats. METHODS: A total of 56 rats were used. They were divided into 2 sedentary control groups, the Ovx control group (C-Ovx) and the sham-Ovx control group (C-Sovx), each with 7 sedentary animals, and 2 treated groups, Ovx and sham-Ovx, with 21 animals each. These two treated groups were subdivided into three subgroups of seven animals each, which received the following treatments: consuming the soy yoghurt+sedentary, only subjected to resistive exercise, and consuming the soy yoghurt+resistive exercise. Both the program of resistive exercise and the consumption of soy yoghurt (at 3 mL/(kg body weight day)) continued for 12 weeks. The soy yoghurt was supplemented with isoflavones at 50mg/100g of product. The animals were sacrificed and their right-side femurs and tibias removed and assessed for bone mineral density (BMD). The alkaline phosphatase activity (AP) was determined in the blood serum. RESULTS: There was a significant increase in both femur and tibia BMD values and in serum alkaline phosphatase activity in all the treated subgroups, compared with the control groups (p<0.05). CONCLUSION: The ingestion of the soy yoghurt supplemented with isoflavones was capable of preventing a loss of bone mass in Ovx rats and of increasing bone mass in sham rats, whilst the resistive exercise program was effective in augmenting the bone mass in sham and Ovx rats.

Glutamina como suplemento ergogênico / Glutamine as a ergogenic supplement

A glutamina (gln) é o aminoácido livre mais abundante no corpo humano representando cerca de 20% do total de aminoácidos livres no plasma e mais de 60% do pool de aminoácidos livres totais no músculo. A gln é considerada um aminoácido condicionalmente essencial sob certas condições clínicas como traumas, estresse, septicemia, câncer e esforço físico intenso. É um importante substrato celular não só por ser um aminoácido, mas por também ser fonte de energia, de nitrogênio e de carbono, para a síntese de outras moléculas. Atualmente, é um dos suplementos nutricionais mais utilizados por atletas e praticantes de atividades físicas como suplemento ergogênico por ser considerado natural e legal, ou seja, passível de promover melhoria de performance e crescimento da massa muscular magra. Com o objetivo de analisar as pesquisas publicadas envolvendo o desempenho no exercício e o uso de suplementação por glutamina e seus possíveis efeitos ergogênicos, utilizamos nesta revisão as pesquisas registradas nos principais bancos de dados eletrônicos e principais revistas científicas da área de nutrição e fisiologia aplicada. Concluímos que muito ainda deve ser pesquisado para o conhecimento efetivo sobre os efeitos ergogênicos da suplementação por gln. The development of physical fitness, as well as sports in their different forms of manifestation, are objectives to be achieved in programs of physical education and sports in which an individual is submitted to a training process. [For this, it is necessary that people train.] Consequently, the physical educator or sports professional must have knowledge of their concepts and relations. From the presentation of evolutive aspects of concepts of physical fitness, sports, and sports training, the aim of this paper was to analyze the relations between them.

Glutamine (gln) is the most abundant free amino acid in the human body, accounting for about 20% of the total of free amino acids in the plasma and more than 60 % of the pool of free amino acids in skeletal muscles. Gln is considered a “conditionally” essential amino acid under certain clinical conditions, such as trauma, stress, sepsis, cancer, and intense physical effort. Glutamine is an important cellular substrate, not just because it is an amino acid, but also because it is a source of energy, nitrogen, and carbon for the synthesis of other molecules. Currently, glutamine is a natural, legal nutritional supplement usually included in the diet of athletes and non-athletes as an ergogenic aid to improve body composition such as lean muscle growth and exercise performance. With the objective of analyzing the literature on exercise, the use of glutamine supplementation and its possible ergogenic effects, this paper examines the main scientific databases and journals on the subject of nutrition and applied physiology. The conclusion reached is that much more research on the ergogenic effects of glutamine supplementation must take place.