UKC

I've got into the habit of using deep heat on my legs before I start a run - something I'm breaking away from as I'm not injured!

However, I'm very curious as to whether or not Deep Heat (other products are available) actually does anything other than stimulating the surface of the skin. I can't honestly say that I've felt any benefit and a good warm up and hand massage to calf muscles before I run seems to be better.

Anyt thoughts or evidence - online sources don't appear to be particularly academic in nature.

In reply to Rampikino:

Scientifically speaking, unpublished data from my own research into the matter (n=1) suggests that when playing rugby on a bitter February morning, it made the first hit easier to bear.

Plus, I like the smell.

In reply to Rampikino:

Use it as chamois cream by mistake then repeat that question! I can assure you it definitely does something.

In reply to Rampikino:
It featured on a BBC programme earlier this year about home remedies. It suggested that it stimulates the nerves making you feel as if it is heating you, but there is no muscle warming.

However, they did say that that feeling alone if applied after exercise can reduce inflammation when compared with applying nothing.

I'm sure it'll still be on I player.... "The truth about your medicine cabinet"

In reply to Rampikino:

It reminds me of school rugby matches if that helps?

In reply to Rampikino:

Good question. Excuse the reference source!

Mentholatum Deep Heating Rub (active ingredients: 30% Methyl salicylate & 8% Menthol, both being external analgesics

Methyl salicylate;
in high concentrations as a rubefacient and analgesic in deep heating liniments (such as Bengay) to treat joint and muscular pain. Randomised double blind trial reviews report evidence of its effectiveness that is weak, but stronger for acute pain than chronic pain, and that effectiveness may be due entirely to counter-irritation. However, in the body it metabolizes into salicylates, including salicylic acid, a known NSAID

Menthol is an organic compound made synthetically or obtained from corn mint, peppermint or other mint oils. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is (&#8722-menthol, which is assigned the (1R,2S,5R) configuration. Menthol has local anesthetic and counterirritant qualities, and it is widely used to relieve minor throat irritation. Menthol also acts as a weak kappa opioid receptor agonist.

In reply to Rampikino:

Searching for 'methyl salicylate' on PubMed gives a few hits, one for inhibiting the progression of arthritis in rats. So there you go.

In reply to Rampikino:
It used to make me whippet run really fast if you put some on its tackle pre rabbit ting

In reply to Rampikino:

From memory when I had similar thoughts on Deep Heat.

It acts as an agonist for ion channels on neurons in a similar way to capsaicin (hot chillis). I believe it acts on the TRPM channel on the neurons responsible for sensing changes in temperature (capsaicin acts on TRPV). These are Transient-Receptor-Potential-(X) channels. These channels open, allowing ions (sodium and calcium mainly) into the neurons. This alone does not cause neurons to fire, but it reduces the threshold for activation, sensitising them.

Crucially this means that the "warm" receptors are activated by body temperature. These receptors are located in the skin, hence why the cream acts so fast.
This may increase blood flow to the skin, which may indirectly increase blood flow to the muscles, but I believe this is BS and actually the only function of deep heat is to provide this feeling of warmth.

The reason this can reduce pain though is that the neurons feeling the warmth flood the CNS (brain) with happy warm feelings, so the CNS "ignores" the pain feelings from the muscles, the sensory neurons from the skin and muscles of an area go to the same place in the brain - This is massively in a nutshell and based on memory , so I may have forgotten something, or made a lot of it up.

from what I remember, the research suggests that deep heat provides no benefit to injured muscles than the massaging effect of rubbing the cream in. So massage may be just as effective.

Having said all that, if it's effective in helping relieve pain, even indirectly, then obviously it has its uses.