|The scientists used an LEDT device from Thor on two points on the distal portion of the vastus lateralis, two points on the distal portion of the vastus medialis and two centered points along the rectus femoris (see Figure 1, right).|
When I started this blog a few years ago, I was guilty of believing that supplements would be the most relevant ergogenics for anyone who trains, myself. Today, ~2,300 articles later, this has changed: don't get me wrong - supplements can be useful, but diet, training and - at least in a few cases - even things like using light emitting diode therapy (LEDT) or low-level laser therapy (LLLT), as it is also called, are much higher on the "things that really work"-list.
In that, it is important to point out that a recent study from the Georgia Southern University (Hemmings. 2016) is neither the first study to show significant performance / recovery benefits from LEDT, nor is it the first study I wrote about (read previous articles). The experiment Hemmings et al. conducted is yet the first to evaluate the effects of different dosages of LEDT (30 vs. 60 vs. 120 seconds on each irradiation point, see Figure 1, right) that was applied by the means of a low-level laser (THOR, London, UK) on muscular fatigue of the quadriceps after two sets of three maximal voluntary isometric contractions (MVIC).
|Figure 1: Comparison of repetitions and blood lactate concentrations between all four trials; illustration of the irradiation points that were used for LEDT (Hemmings. 2016)|
|LLLT therapy has also been shown to almost double the muscle gains in a study with an 8-week eccentric training program | more|
A recent meta-analysis (Nampo. 2016) evaluated both, the effects of LLLT and LEDT, on exercise capacity and muscle performance of people undergoing exercise when compared to placebo treatment. Sixteen studies involving 297 participants were included in the meta-analysis that shows a mean improvement of the number of repetitions of 3.51 reps (0.65–6.37; P = 0.02), a 4,01 second delay in time to exhaustion (2.10–5.91; P < 0.0001), and - unlike the study at hand - a sign. reduction in lactate levels (MD = 0.34 mmol/L [0.19–0.48]; P < 0.00001) and increased peak torque (MD = 21.51 Nm [10.01–33.01]; P < 0.00001).
|Exercise capacity - Number of reps (left), time to exhaustion (right | Nampo. 2016)|
|Lactate is not the enemy - remember? Caffeine and Bicarbonate (NaHCO3), two proven ergogenics increase, not decrease blood lactate accumulation while still boosting subjects' performance during a standardized yo-yo performance test | learn more.|
What about gains and does timing matter? No, you don't have to be afraid that LLLT would have the same negative effects on your gains as ice-baths. It has, after all, already been shown to double the gains in a 2015 8-week study in healthy volunteers | read more! And the timing, yeah... Well, yes timing does matter! You have to apply it before the workout to see effects... at least for immediate 1RM strength gains this is the case according to a very recent study by Vanin (2016) - future studies will tell if using it post, as a recovery tool can be effective in the long-term.As a SuppVersity reader you will, for example, remember that proven ergogenics such as bicarbonate and beta alanine increase the accumulation of lactate significantly... ok, you may argue that they simply protect the muscle from the tiring effects of lactate, but eventually there are other more likely candidates to explain the onset of fatigue such as the accumulation of other muscle metabolite, a decrease in free energy of adenosine triphosphate, limited O2 or other substrate availability, increased glycolysis, pH disturbance, increased muscle temperature, reactive oxygen species production, and altered motor unit recruitment patterns (Grassi. 2015; Poole. 2015), which could eventually explain why our muscles fatigue and why the lactate levels increase (reduced ATP, for example, will necessarily increase glycolysis and eventually the lactate accumulation).
- Bublitz, Caroline, et al. "Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure—a pilot study." Lasers in medical science (2016): 1-7.
- Byrne, Christopher, Craig Twist, and Roger Eston. "Neuromuscular function after exercise-induced muscle damage." Sports medicine 34.1 (2004): 49-69.
- Grassi, Bruno, Harry B. Rossiter, and Jerzy A. Zoladz. "Skeletal muscle fatigue and decreased efficiency: two sides of the same coin?." Exercise and sport sciences reviews 43.2 (2015): 75-83.
- Hemmings, Thomas J. "Identifying Dosage Effect of LEDT on Muscular Fatigue in Quadriceps." Journal of Strength and Conditioning Research (2016): Publish Ahead of PrintDOI: 10.1519/JSC.0000000000001523..
- Poole, David C., and Thomas J. Barstow. "The critical power framework provides novel insights into fatigue mechanisms." Exercise and sport sciences reviews 43.2 (2015): 65-66.
- Vanin, Adriane Aver, et al. "What is the best moment to apply phototherapy when associated to a strength training program? A randomized, double-blinded, placebo-controlled trial." Lasers in Medical Science (2016): 1-10.