LED blanket improves athlete performance and can help in treating obesity

Prototype developed by Brazilian researchers can help in sports training and patient rehabilitation and is expected to reach the market by the end of the year.

By Karina Toledo

Agência FAPESP – Researchers at the Federal University of São Carlos (UFSCar), Brazil, have developed a blanket with LEDs (light emitting diodes) that has been proven in clinical and pre-clinical testing to have the capacity to increase muscle strength and resistance provided by the physical activity while also reducing inflammation and accelerating post-training tissue regeneration.

The product, developed in partnership with scientists from the São Carlos Institute of Physics (IFSC) at the University of São Paulo (USP), was patented and is expected to reach the market before the end of 2014.

Some of the research was conducted with FAPESP funding as part of the doctoral research of Cleber Ferraresi. The advisor on the project was Prof. Nivaldo Antonio Parizotto, of the Center for Biological and Health Sciences (CCBS-UFSCar), who gave a lecture on phototherapy at the 29th Annual Meeting of the Brazilian Federation of Experimental Biology Societies (FESBE) held in August in Caxambu (MG).

“Low-intensity phototherapy works together with physical exercise to cause muscle tissue to respond more intensely to the stimulus and produces a very interesting performance effect. It can be useful in sports, as well as in the rehabilitation and functional recovery of patients in a variety of circumstances,” Parizotto said in an interview with Agência FAPESP.

According to the researcher, the blanket will be made of a plastic material and will have 50-200 LED bulbs of various sizes, according to the part of the body to be treated. It can be used in two different wavelengths: red (630 nanometers (nm)) and infrared (850 nm).

“We’ve conducted several studies to determine what dose is needed to obtain the best muscle response and when phototherapy is most effective. Our data show that ideally, intervention soon after physical activity is best,” Parizotto explained.

He went on to explain that the light helps stimulate what are known as satellite cells – a type of stem cell found in peripheral muscle fibers. These cells remain in a quiescent (resting) state until they are activated through physical exercise. They then proliferate, differentiate and regenerate the injured muscle fiber and increase the tissue.

“We know that the practice of physical activity stimulates the release of oxygen free radicals, causing what is known as oxidative stress. Our studies indicate that using the blanket after training promotes the entry of certain enzymes into muscle cells to help neutralize these free radicals, thereby reducing inflammation and fatigue and accelerating muscle regeneration,” Parizotto said.

Mechanisms of action

This group of researchers has conducted several experiments in an attempt to further explain the mechanisms through which phototherapy helps muscle tissue.

During Ferraresi’s doctoral research, for example, experiments involved the use of microarray technology to analyze the expression of 44,000 genes in volunteers who underwent strength training.

“To evaluate changes in the patterns of gene expression, we took biopsies of the vastus medialis oblique muscle of the thigh before and after training. We also analyzed muscle strength using a method known as isokinetic dynometry,” Parizotto explained.

The volunteers were separated into two groups. Both performed quadriceps weight training exercises for a period of 12 weeks. After the training sessions, half received phototherapy and the other half received a blanket that only simulated the treatment.

In the phototherapy group, the strength measured in the target muscle increased by nearly 55%, compared with only a 27% increase in the other group. The findings were published in the journal Lasers in Medical Science.

“Microarray analysis showed that the LED blanket increased gene expression related to muscular hypertrophy and reduced the expression of genes that inhibit the increase in muscle mass. In other words, it created a molecular structure to sustain this greater increase,” the researcher said.

In another clinical study conducted during the master’s research of Wouber Hérickson de Brito Vieira, also under the advisorship of Parizotto, 45 women performed aerobic strength training using a stationary bicycle for 12 weeks, and some of them received post-training phototherapy treatment on the quadriceps femoris muscle.

Analyses showed that the phototherapy reduced muscle fatigue and improved exercise tolerance. These findings were also published in the journal Lasers in Medical Science.

Another clinical study was conducted during the master’s research of Thiago Maldonado, this time with 16 young professional athletes from the Palmeiras Soccer Club.

“All of the volunteers followed the training routine prescribed by the athletic trainer for five days a week over the course of six weeks, but one group received the LED blanket on the thigh muscle after training, while the other group received only a placebo treatment,” Parizotto explained.

According to the researcher, at the end of the experiment, the group that had received phototherapy demonstrated superior physical performance in the vertical jump (9.4% among blanket users compared with 3.6% among placebo users) and forward leap (8.8% among blanket users compared with 3.2% among placebo users), as well as faster sprint speeds (-2.97% among blanket users compared with -1.04% among placebo users).

Obesity treatment

Another arm of the study is being carried out in partnership with scientists from the Federal University of São Paulo (Unifesp), who are investigating the effectiveness of the laser blanket in treating obesity.

During clinical trials, 64 women performed one hour of training that combined aerobic and weight training exercises three times per week. The group that received phototherapy directly after the training sessions presented a 48% higher loss of body mass. They also experienced higher overall fat loss (47%) and visceral fat loss (53%), greater reductions in waist (35%) and hip (72%) circumferences and marked improvements in lipid profiles (reduction of cholesterol and triglycerides).

The researchers are currently analyzing how phototherapy modulated the production of inflammatory cytokines in the adipose tissue of the volunteers.

“As you know, obesity is associated with a chronic inflammatory response. The blanket helps contain this inflammation and increase fat burning during physical activity,” Parizotto said.