Exercise is Medicine

by Jade Teta ND, CSCS, and Keoni Teta ND, CSCS, LAc

Vascular Occlusion Training for Muscle Growth

Vascular occlusion training (VOT) is a workout technique that slows the removal of blood from a particular muscle group by applying pressure distal to a muscle group. Blood pressure cuffs or elastic bands are applied to a muscle, such as the biceps femoris, to occlude the blood vessels and decrease venous return. The purpose of this technique is to increase the accumulation of local metabolic byproducts. These compounds include lactate, IL-6, IL-15, and other “muscle molecules.” They are not simply waste material but now understood to be potent stimulators of muscle growth and fat loss through intracellular and hormonal mechanism.^4–12

Review of Vascular Return

Unlike arteries, veins have low pressure. They depend on valves and both the contraction and relaxation of muscles to help return blood to the heart. Valves keep blood from flowing backwards and moving muscles create a pumping action on the vessels to push blood forward.

Squeezing a muscle, like a biceps, causes a contraction that constricts the blood vessels. When the tension is released, the blood vessel relaxes. This contraction and relaxation when coupled create a pumping action, with the valves assuring that blood moves in the right direction.

Muscle Molecules

IL-6, IL-15, nitric oxide, and lactate are often thought of as detrimental compounds, unique to the immune or vascular system or simply waste products. However, they are each now known to have profound impacts on metabolism and are actually part of exercise’s cascade or beneficial effects.^4–12

IL-6 when it is released from muscle can increase up to 100 times. Contrary to its effects when coupled with TNF alpha and IL-1 beta, IL-6 in the concentrations generated during exercise is anti-inflammatory.¹³ It raises levels of IL-10 and lowers TNF alpha and IL-1 beta by increasing soluble TNF alpha receptors and IL-1 receptor antagonists.^7–8,13 It also crosses over into hormone action increasing fat breakdown.

Il-15 is released from muscle during exercise as well. It is stimulated mostly by contraction of type II muscle fibers. IL-15, like IL-6 is hormonelike in action when released in the context of exercise. Its increases muscle protein synthesis and fat breakdown.^4–6

Lactate and nitric oxide are both generated and released from muscle tissue where they can act in autocrine, paracrine, or in the case of lactate, endocrine fashion.^9–8 The signal sent by these molecules is an adaptation signal. They both increase mitochondrial synthesis. Lactate, in possible hormonal action (a receptor was recently discovered for lactate), stimulates both HGH and testosterone release.^9,11

Together, Il-6, IL-15, NO, and lactate are potent stimulators of metabolic adaptation. Muscular contractions under occlusion stimulate the metabolic accumulation of these compounds. This may lead to increased growth hormone production, increased activation of fast-twitch muscle fibers, and a host of other changes that increase muscle stimulation and growth.

Research on VOT

A recent study in the January 2010 issue of the International Journal of Sports Medicine reviewed the most recent understanding of VOT.³ The common dogma regarding weight training intensities for muscle growth dictate 4 to 5 sets of 8 to 12 reps with a weight between 65% and 75% of a 1RM (i.e., a weight that can be lifted one time only, where the second rep is impossible).

This review highlights studies showing vascular occlusion with 45% to 55% lighter weights generates the same growth stimulus of traditional weight-training protocols. This means vascular occlusion protocols may be able to bolster results while minimizing injury risk. This is an appealing tool when dealing with the frail and elderly.

Other studies have shown vascular occlusion greatly increases the production of growth hormone despite very light loads. Takarada et al. and Suga et al. have demonstrated that this effect is coming through multiple mechanisms and includes metabolic accumulation possible through accumulation of the compounds mentioned above.^1,2

Contraction Occlusion

There are two ways to impose vascular occlusion. One way is to apply a tourniquet distal to a muscle to slow the removal of blood and metabolic byproducts from the area. This is the way it is done in research. However, this method is not clinically viable for health professionals wishing to utilize the benefits of this style of training.

There are different workout techniques that may be able to generate a similar effect. Manipulating muscular contraction is one potential solution. The idea is to use the squeezing action of a contracted muscle to “clamp down” on blood vessels and slow venous return. This may increase the metabolic accumulation of the key signaling molecules mentioned above.

Pulsing contractions (where the muscle is repeatedly contracted while not allowing it to fully relax: or holding muscle contractions (where the muscle is squeezed hard and not released for a period of time) can act as the poor man’s version of vascular occlusion.

Occlusion Workout

There are several ways to use pulses and holds in your workouts. One option is to do a straight set and then a hold or pulse at the end. For example, if you are doing a biceps curl, you would first complete 10 traditional repetitions. At the conclusions of the set and before resting, you would bring the weight to the middle of the range of motion (upper and lower arm at 90 º) then either hold by squeezing down hard, or pulse by squeezing hard and slightly relaxing repeatedly.

This holding or pulsing portion of the set should be held until the muscle reaches full fatigue. Burning in the muscle is a good indication the metabolic accumulation is occurring. The contraction occlusion method can be used in a number of ways. Pulses and holds have been mentioned, but very slow reps, partial reps, and any other method that manipulates and focuses the contraction a muscle can work. These techniques are also easy to teach clinically.

Here is a quick occlusion workout:

• Choose two exercises for the three biggest muscle groups (e.g., squats and leg curls for legs, chest press and dumbbell chest fly for chest, lat pull-downs and rows for back).

• Do 3 sets of 10 for each exercise.

• At the end of each set, do a 10-second hold followed by a 10-second pulse

• Rest 1 to 2 minutes before going to the next exercise.

Notes

1. Takarada et al. Rapid increase in plasma growth hormone after low intensity resistance exercise with vascular occlusion. J Appl Physiol. 2000;88:61–65.

2. Suga et al. Intramuscular metabolism during low-intensity resistance exercise with blood flow restriction. J Appl Physiol. 2009;106:1119–1124.

3. Loenneke et al. A mechanistic approach to blood flow restriction. Int J Sports Med. Jan 2010;31(1):1–4.

4. Nielson et al. Expression of interleukin-15 in human skeletal muscle – effect of exercise and muscle fibre type composition. J Physiol. 2007;584(1):305–312.

5. Quinn et al.Oversecretion of interleukin-15 from skeletal muscle reduces adiposity. Am J Physiol Endocrinol Metab. 2009;296(1):E191–E202.

6. Nielson et al. Association between interleukin-15 and obesity: interleukin-15 as a potential regulator of fat mass. Clin Endocrinol Metab. 2008 Nov;93(11):4486–4493.

7. Pederson et al. Role of myokines in exercise and metabolism. J Appl Physiol. 2007;103:1093–1098.

8. Pederson et al. Muscle-derived IL-6 – a possible link between skeletal muscle, adipose tissue, liver and brain. Brain Behav Immun. 2005;19:371–376.

9. Liu et al. Lactate inhibits lipolysis in fat cells through activation of an orphan g-protein-coupled receptor, GPR81. J Biol Chem. 2009 Jan;284(5):2811

10. Ho Lin et al. Stimulatory effect of lactate on testosterone production by rat Leydig cells. J Cell Biochem. 2001;83:147–154.

11. Luger et al. Plasma growth hormone and prolactin responses to graded levels of acute exercise and to a lactate infusion. Neuroendocrinology. 1992;56:112–117.

Lee-Young et al. Endothelial nitric oxide synthase is central to skeletal muscle metabolic regulation and enzymatic signaling during exercise in vivo. Am J Physiol Regul Integr Comp Physiol. May 2010;298(5):R1399–1408.

12. Teta J, Teta K. Exercise is Medicine: the anti-inflammatory effects of high intensity exercise. Townsend Lett. November 2006.