An increasingly popular trend in sports performance programs has been increased attention to recovery and regeneration methods. Sports performance training, such as weight lifting, conditioning, and plyometrics, are methods that can help individuals improve their sports performance, but at the same, may result in fatigue, delayed onset muscle soreness (DOMS), and a potential decrease in future performance if recovery is not complete before the next strenuous training session. Athletes who recovery quickly may begin to train at higher intensities compared to those who are not fully recovered. Additionally, new technology for sports performance has become increasingly popular as well.
One technological advancement within the past ten years has been the use of low level laser therapy (LLLT). LLLT was approved for use by the FDA in 2002. LLLT has been found in 2500 articles and shown positive results in 120 double blind studies. It has become increasing popular in physical therapy and chiropractic practices to treat pain, reduce inflammation, and other issues specific to those practices. It was not until recently that research has begun to show LLLT has the potential to increase human performance in healthy subjects.
Light amplification by stimulated emission of radiation (LASER) has been used for a variety of medical purposes since the 1960s. Low level laser therapy, also referred to as cold laser, or phototherapy, is a low powered laser that is not able to cut through skin, unlike many surgical lasers. Lasers that are surgical are able to provide enough heat to the tissues to increase temperature over 50 C. LLLT is typically infrared light with wavelengths of 632.5-904 nm with power ranging from 5mW to 25,000mW. Some devices may also include light emitting diodes (LEDs), which have a scatter effect of light, compared to a narrow beam seen from a laser. Devices also come with options of continuous or pulsed light. Pulsed light is more powerful and can penetrate deeper depths in the tissues. It is able to achieve greater light intensity extending deep into the tissue.
Mechanisms of LLLT
LLLT can have a local effect and a systemic effect on an individual. The benefits from a local treatment include increased cell metabolism and collagen synthesis in fibroblasts, increase in action potential of nerve cells, increased immune function, stimulation of DNA and RNA synthesis in the nucleus, increased formation of capillaries by release of growth factors, and increased leukocyte activity..
Systemic effects occur when cells products substances that spread and circulate in blood vessels and lymphatic system. Acupuncture points, trigger points, blood irradiation, lymph nodes, and nerve roots may all be stimulated in order to get systemic effects. LLLT is safe when used properly. Individuals known to have cancer, are pregnant, and are sensitive to light are recommended to not use LLLT. Unlike ultraviolent light which has been shown to cause mutations, LLLT uses infrared wavelengths and are considered safe.
The laser provides photon energy to penetrate the skin, where cellular photoreceptors, more specifically within mitochondria, accept the energy and lead to increased speed on cellular processes. It’s been demonstrated that LLLT influences cytochrome C oxidase in the electron transport chain. Cytochrome C oxidase is the terminal enzyme of the electron transport chain, and when stimulated, increases adenosine triphosphate (ATP) production. ATP Is the main energy source of the cell, and an increase in its production would lead to enhanced cellular function.
During exercise, ROS is generated from contracting skeletal muscle, with nitric oxide (NO) and superoxide being the primary agents. The tissues have a well-developed system to regulate ROS and prevent potential harmful effects. Slow-twitch fibers have a higher concentration of these protective systems than fast twitch fibers. During the inflammatory response, ROS is produced by neutrophils to attack degenerated cells. This increase in ROS is one of the initial events in exercise induced muscle injury, often seen after intense exercise. Since the tissues may be damaged to some degree, these cells and tissues will need ATP to provide energy for the repair process.
When investigating muscle damage and fatigue, common blood markers include blood lactate, creatine kinase, and C reactive proteins (CRP). Blood lactate concentration is widely used to monitor performance and recovery, and it is also a surrogate marker of recovery after exercise. The CRP concentration is a very useful nonspecific biochemical marker of inflammation, measurement of which contributes importantly to (a) screening for organic disease, (b) monitoring of the response to treatment of inflammation and infection, and (c) detection of intercurrent infection in immunocompromised individuals, and in the few specific diseases characterized by modest or absent acute-phase responses.
With this background in place, research by Junior et al. in 2010 found that LLLT pre-exercise LLLT helped increased endurance for repeated elbow flexion against resistance and decreased post-exercise levels of blood lactate, creatine kinase, and C reactive protein. This study is helps provide insight that LLLT has potential to provide performance enhancement benefits from a recovery and workout perspective. Strength and conditioning coaches looking to reduce post exercise fatigue may want to include LLLT into their warm-up and preparations for workouts.
Immune System Modulation
It has been established that a chronic dose of intensive training can decrease immune function. At this point, individuals are likely to become sick and may be required to miss training to recover from such an illness. Using LLLT, athletes may be able to boost immune function. According to Tuner & Hode, blood irradiation using LLLT, also called photohemotherapy, has been used in Russia for many years. When the blood is irradiated, there is improvement in immune system, microcirculation, decrease in blood viscosity, increased oxygenation, normalization of homeostasis, and activation of the proliferation processes. This area of study is still relatively new in research circles, however, the current literature exists to show that laser therapy plays a role in activating and boosting the normal reaction of the immune system components.
From a sports performance perspective, this technique has many important applications. First, intense exercise has been shown to decrease immune function. Decreased immune function is an attribute of intensive training and will eventually lead to decreased performance and potentially illness. Following intensive exercise, the body may see elevated temperatures, cytokines, and stress-related hormones may lead to depression of the body’s immune defenses. Fighting this is important in order to maintain optimal performance.
Immunomodulation through blood irradiation (applying laser to a highly vascular area of the body) is important during an athlete’s basic training period, also called general preparation phase. Further, immunomodulation may take place during later phases of training following the basic training phase. According to Potemkin’s protocols, athletes may receive treatment on the apex beat of the heart and on the cubital fossa for a course of 10 days and may be repeated later on in training. During the specialized training phase, additional areas may be treated and include the liver and spleen, which both play an important role in blood physiology. Protocols during strength training include treating specific muscles for short periods of time.
Another benefit from regular photohemotherapy is an increase in microcirculation. Microcirculation includes small blood vessels in the body consisting of the capillary network, the arterioles, and the venules. Microcirculation is responsible for regulation of blood flow in individual organs and for exchange between blood and tissue. Approximately 80% of the total pressure drop between the aorta and the vena cava occurs in these vessels.
An increase in microcirculation improves the body’s self-healing capacity due to increased blood flow to tissues. In a recent study, they found treating areas around the knee led to increased microcirculation. Nitric oxide (NO) is one of the most important physiological regulators of the microcirculation, which activates vasodilatation via activation of cGMP-dependent pathway. Further, it appears blue wavelengths of light might have additional benefit when it comes to blood irradiation.
Blood viscosity, which is the resistance to blood flow, plays an important role in oxygen delivery to the cells. Increased viscosity leads to a decreased on oxygen delivery to the cells. Since LLLT has been shown to decrease viscosity, there would be an increase in oxygenation to the cells. Photohemotherapy would be used during general and intensive training periods.
A common concern using LLLT is the recommended treatment times to achieve results. According to Potemkin’s recommendations using a 25,000 mW super pulsed laser with a 905 nm wavelength required treatment times of 1-2 minutes for most sites per athlete. Devices with smaller wavelengths and less power might require more time to achieve similar results. Additionally, many treatments can be done multiple times a day, as recommended in the table below.
Table: Applications of Low Level Laser Therapy on Sports Performance
|Before Exercise||During Exercise||After Exercise||Other|
|Immunomodulation||AM & PM|
For the strength and conditioning coach, there are many ways to implement laser therapy into a training program. The easiest and fastest protocol would be photohemotherapy administered prior to workout. The laser would be applied to the athlete’s cubital fossa, carotid artery region, or to the apex beat of the heart, all for a period of one to two minutes total treatment time. Ideally this would be done before a workout begins. In a team setting, laser treatment might be included as part of a warm-up station that allows all athletes to participate in a warm-up sequence while getting benefits of laser. Additional lasers would reduce the logistical issues associated with treatment. This treatment would be best suited during the general preparation phases of a yearly training plan.
Laser may also be applied during the strength training segments of workouts. Ideally, the athlete would laser the targeted muscles prior to the session. In larger group settings, applying laser during rest can help keep workout tempo quick, since a treatment time of about one minute is usually required. A three person group may rotate in a spot-lift-laser sequence. It has become increasingly popular for exercise routines to incorporate multiple sets per exercise. In exercises such as squats where multiple muscle groups are involved, the athlete may apply laser to the quadriceps on the first and second sets, the hamstrings on the third and fourth sets, and other areas such as lower back on any additional sets that may be required. In a program that requires only one set of an exercise, such as squats or deadlifts, the athlete can split the treatment time in half. Using this technique would appear to work well in programs that utilize a maximum strength phase that incorporates longer rest periods between sets, compared to shorter rests and lighter loads often seen in the general preparation phases. Since a maximum strength phase would have a limited number of lifts, each athlete would have the potential to utilize the rest time with laser treatments on various muscle groups.
In early 2014, Oregon Project coach Alberto Salazar publically discussed the teams use of LLLT
During therapy sessions, LLLT can be used depending on the athletes status during the session. For example, a runner comes to see me with tightness in the hamstrings and a painful sensation in the Achilles region. I would use the laser for a few minutes on both inguinal regions aiming for the femoral artery and nerve, as they can be reached with larger wavelength lasers. This serves to increase blood flow in a major circulation “highway” that transports blood down through the entire lower leg. Depending on how large of an area, I would move the laser the impaired muscles. Often a trigger point can be done, or a larger scan of the entire muscle. For the Achilles, I would first treat the popliteal fossa, for the same reason we did the inguinal region. Then I would scan the Achilles on the sides, not directly on top of it. I would expect the Achilles pain decreased, if not eliminated following the session, and a sense of looseness in the muscle regions. There is a time delay as a result of the reactions that occur. I would then begin manual massage work as needed on the athlete.
LLLT shows tremendous potential as an innovative and effective recovery and performance enhancement option. As more research is done, LLLT will continue to show promising uses in sports performance. It’s short treatment times allow many athletes to receive treatment in a short time, which is so important in settings such as collegiate environments where time for training is limited based on time of year. Sports performance coaches should explore the possibility of incorporating LLLT into their training plans and joining efforts with their athletic training staff to ensure each athlete performs at their optimal level.
Phototherapy 101. Douglas Johnson (2007)
Ernesto Cesar Pinto Leal Junior et al. Effects of Low-Level Laser Therapy (LLLT) in the Development of Exercise-Induced Skeletal Muscle Fatigue and Changes in Biochemical Markers Related to Postexercise Recovery J Orthop Sports Phys Ther 2010;40(8):524-532.
C-reactive protein: a critical update. Mark B. Pepys and Gideon M. Hirschfield J. Clin. Invest. 111:1805–1812 (2003).
Low-Intensity Light Therapy: Exploring the Role of Redox Mechanisms Joseph Tafur, M.D. and Paul J. Mills, Ph.D. Photomedicine and Laser Surgery Volume 26, Number 4, 2008 Pp. 323–328
The Laser Therapy Handbook. Jan Tuner & Lars Hode (2004)
Biomedical Support and Quantum Medicine of Top Achievement Sport. Leonid Potemkin (2001)
Lenz et al (2008) Blood viscosity modulates tissue perfusion. Transfus Altern Transfus Med 9(4) 265-272.