Benefits of Lactate during Exercise

An increase in lactate levels during training helps you to manage energy resources and to adapt your body to exercise.

Athletes and coaches often consider lactate only as a source of fatigue and pain, but this is not true. Lactate is not a dead endpoint of anaerobic metabolism, but a molecule that contains fuel and can be moved around in your body as needed. It also acts as a signal to your muscles to adapt to exercise.
Our cells store only a small amount of ATP (= molecule containing energy), which means that they have to replenish their stores continuously. They have three mechanisms to do so: the ATP-phosphocreatine system, the glycolytic system and the oxidative system.
The ATP-phosphocreatine system
Phosphocreatine is a high energy molecule which can be broken down to generate ATP. It is a very quick system that does not require oxygen and does not produce lactate, but as there is only a limited amount of phosphocreatine available, it is only used for the 5 to 15 first seconds of high intensity exercise. It is therefore only interesting for sprinters, and not for endurance athletes.
The glycolytic, oxygen independent or anaerobic system
We can also generate ATP by breaking down glucose or glycogen. This is a quick system that does not require oxygen, but produces only a limited amount of ATP. It is the preferred system of the fast switch (type 2) fibres. The end product is pyruvic acid, which can be taken up in the oxygen dependent system (see below) or transformed into lactate.
The oxidative, aerobic or oxygen dependent system
Pyruvic acid can be taken up by mitochondria, which are the cell’s energy plants. It enters then a complex series of chemical reactions and finally produces a large amount of ATP. This system is slow and requires oxygen, but as it can produce a large stream of energy for a long time, it is preferred by the slow switch (type1) fibres.
Increasing the intensity
Recent studies have shown that the amount of oxygen present in the muscle cells never decreases that much that the oxidative system has to stop. The terms “anaerobic” and “aerobic” are thus incorrect, and should be replaced by “oxygen independent” and “oxygen dependent”.
As you increase the intensity of your workout, only the oxygen independent system is quick enough to respond, and it will produce more pyruvic acid than the slower, oxidative system can handle. If your cells produce more pyruvic acid, more lactate will be formed.
Moving energy around
Contrary to popular believe, lactate is not a waste product, but an energy rich molecule. It reaches the bloodstream and is taken up by neighbouring type 1 fibres, other muscles, the liver, the heart, the brain or about any other organ. It is then transformed back into pyruvic acid and used as fuel. In the liver and in inactive muscles, it can even be transformed back into glucose or glycogen and stored.
The point at which the lactate production exceeds the clearance is called the lactate threshold. Obviously, it is not a real threshold but a gradual process. As you get fitter, your body becomes better at taking up and using lactate from the bloodstream, and you will able to work harder or run faster before reaching your threshold.
A signalling molecule
Scientists now believe that lactate also promotes the formation of new mitochondria, and therefore makes your muscles better adapted to exercise.
To stay healthy, your body has to maintain a balance between the different chemical substances in your cells and fluids. Some scientists think that an increasing amount of lactate in your blood is a signal for your unconscious brain that you are working very hard, and that this balance might be disrupted if you continue. To make sure that this will not happen, your brain will slow you down by making you tired and recruiting less muscle fibres. This is in accordance with the central governor theory, about which I have blogged previously.
The good and the bad
All the chemical substances in your body have advantages and disadvantages, and there are therefore no bad molecules. It is all about balances. Lactate is not an exception, and it deserves a much better reputation than it actually has in the popular press.
Love lactate and enjoy your workout!
References
G A Brooks. Cell – cell and intracellular lactate shuttles. J Physiol 2009; 587(Pt23): 5591-5600.
R S de Oliveira Cruz, R A de Aguiar, T Turnes et al. Intracellular shuttle: the lactate aerobic metabolism. ScientificWorldJournal 2012, 2012: 420984.
A Philp, A L Macdonald and P W Watt. Lactate – a signal coordinating cell and systemic function. J Exp Biol 2005; 208: 4561-4575.

The Health Wonder

The medicinal properties of nature are beneficial in treating disorders ranging from skin abrasions to microbial infections.

 

Eastern medicine has used the curative properties of neem in a variety of ways for centuries. In a poultice, it was applied to raw wounds to dry and disinfect the area. Before the era of toothpaste, people would chew pieces of the bark of a neem tree to freshen their morning breath. Children with chickenpox would be bathed with water in which neem leaves had been soaked overnight to calm the itchy rash. Noticing that a lane lined with neem trees attracted less mosquitoes and pests, people burned neem bark as a bug repellent, much like the citronella candles of today. In fact, the uses of neem were believed to be so wide spread that it came to be known as sarvroghari or, quite literally, 'ridder of all disease'. Octogenerian Jagdish Goel, a scholar and avowed neem fanatic, agrees and credits his advanced, disease-free age to this wonder herb.
Neem as an antiseptic

• A warm poultice made with crushed neem leaves and turmeric helps to soothe wounds, reduce swelling and hasten healing.
• Neem leaves boiled in water, cooled and crushed can be applied to skin sores caused by chicken pox, eczema or ulcers to relieve associated symptoms such as itching and to prevent infection of open sores.

Neem as anti-microbial treatment

• Neem oil taken orally as is or in capsule form helps prevent the overgrowth of candida, a fungus whose proliferation in the body can cause yeast infections.
• Neem preparations, specifically oil derived from its seed kernel, have been scientifically shown to be effective treatments for athlete's foot, ringworm of skin and nails and other fungal infections of the lungs and mucous membranes.
• Many diseases caused by microorganisms living inside insects have potential to be treated with neem concoctions. In India, neem-leaf teas have been found to be effective in the treatment of malaria, which is caused by a protozoan found inside mosquitoes that reside in that region.

Neem as an insecticide

• Pure neem oil rubbed onto the scalp is an effective treatment of head lice.
• Essential oil of neem can be used in a homemade preparation as an insect repellant. The oil's intense odor repels mosquitoes and other small insects.

Neem as a contraceptive

• Neem oil is believed to be an organically strong spermicide. Research is underway to isolate components of the oil of a neem seed kernel that can be developed as an effective birth control measure. Neem oil works by slowing down sperm mobility enough to prevent fertilization.
• Neem oil also works as a veritable "morning after pill". Applied inside the uterus, it prevents implantation of the fertilized egg thus preventing pregnancy.

Indigenous to a sizeable region of the world, neem has the potential to have far reaching medical consequences. With focused research, this inexpensive, non-toxic and organic source can be utilized to its full extent as the miracle herb that it is touted to be. However, until that point is reached, caution and common sense needs to be applied to all handling of this wonder that is neem.
References:
'Neem: A Tree for Solving Global Problems'. The National Academies Press (Accessed 9/17/2012)
'Neem'. Organic India (Accessed 9/15/2012)
Upadhyay, Kaushic and Talwar. 'Antifertility Effects of Neem Oil by Single Intrauterine Administration: A Novel Method of Contraception'. Proceedings of the Royal Society Series B. Biological Sciences.