Arsen Gere
Guru
- Location
- North East, UK
Over the years I have read a load of questions and seen answers to them without any real justification. An article in Cycling Active prompted me to read up on something called Interleukin-6 and a lot of the answers dropped in to place for me. So I have compiled some of the things I have read in to something that is easier to understand. I hope it helps you too.
Interleukin-6 (IL6) is a cytokine, a messenger produced by quite a few parts of the body but key ones are muscles and the brain. It has a role in lypolysis (fat break down) it acts as a signal to adipose (fat) tissue. So it plays a part in weight loss and the use of fats rather than sugars in exercise. It also passes across the blood-brain barrier, so IL6 from your legs gets in to your brain.
Its production is not uniform; exercise duration is the key generator for muscle IL6. Exercise intensity has a part to play too. Intense exercise intervals for a period of two hours generates the same sort of levels of IL6 as 4 to 6 hours of longer lower intensity exercise.
Running generates IL6 faster than cycling and over 100 times the background level, but cycling generates a significant amount too. 5 times the normal background level is easy to achieve and this can be as high as 50 times.
IL6 is generated during illness (up to 10,000 time background level), temperature (cold) and exercise can generate up to 110 times background levels. Its production is impaired by blood glucose. Remember these points. IL6 makes exercise harder. This was proven by randomly sampling athletes, injecting IL6 and getting them to run 10k. Those injected were significantly worse performers. So the more there is in your blood the worse you perform at any sport.
IL6 is processed in the brain to produce prostaglandins, these flood your body when you are ill and make it ache. Taking paracetamol reduces the pain caused by prostaglandins. So when you take a lemsip when you have flu you may feel a bit better.
In your resting state, high levels of IL6 are associated with heart attacks.
IL6 background levels fall if you exercise regularly. So you can see how these two may be linked together.
IL6 production declines as the muscles become more efficient when doing the same routine.
IL6 levels peak at around 1 hour after you stop exercising.
IL6 levels are reduced by anti-oxidants, vitamins C and E.
So armed with these facts lets look at some common questions on this forum and see where IL6 may have a role to play. (NB. It does not work in isolation).
Q1: I am doing the same amount of exercise and I have stopped losing weight.
IL6 mobilises the fat store for energy production, your body is more efficient and the levels of IL6 produced have declined, so fat breakdown is not taking place at the same rate. The answer to this is to increase the intensity or duration of exercise to increase IL6, break down the fat and get you to a satisfactory body state/shape.
Q2: I’ve been out and run 18 miles, I had no food or drink during this exercise and I felt ill afterwards, like I had cold or flu, aches. The level of IL6 produced in running is high, no carbs taken means IL6 was even higher (because it was not suppressed). This caused the production of prostaglandins and it makes you feel ill. (Aches, not throw up – sick ).Take a paracetamol and htfu.
Q3: When I swim in the sea, I feel really sleepy tired afterwards unlike in the pool. The exercise and cold temperatures mean your muscles and brain were producing IL6. This caused an increase in cortisol. You need to have 20 mins lie down and shut your eyes, nod off a bit, may be the odd twitch as you fall in/out of sleep. This will sort out the cortisol, serotonin, melatonin and you’ll be fine in no time. If you don’t you’ll feel miserable but not ill. This affects over 40’s more than younger people.
Q4: I bonked a couple of weeks a go now I am flying (Barry Hoban). IL6 production was high when you bonked due to the muscle exhaustion and very low carbohydrates in your blood. Your body has adjusted to this effect, background IL6 is lowered, your muscles are more efficient and produce less IL6 and this effect can last for 3 months or more. Your body is also prepared to break down fats more readily and does not go directly to your carb store, (muscles and liver). So racing or hard exercise seems easier and you don’t depend so much on sugar reserves.
Q5: Does carb depleted training work? Yes. Low carbs = higher IL6 levels. Train carb depleted to artificially increase IL6 levels (ie don’t eat two hours before training and don’t swig on sugary drinks), your training performance will suffer. Background levels of IL6 will fall and muscle production will decrease as in the fat loss case. Race carb loaded to prevent IL6 production and you get a performance increase for the cost of a few jelly babies. Use a carb depleted training regime as your reference, not that one fantastic training session you had when you stuffed your face. If you want fast training sessions and slow races then train carb loaded.
Q6: Should I do long miles if I am only doing short races? Yes, IL6 is produced most effectively by doing long rides 4hrs+, you will benefit from a reduced background IL6 level and lower muscle levels. This can complement higher intensity intervals over a shorter period.
Q7: I feel sleepy tired after a long ride. See Q3.
Here is a meta-study, a summary of a number of papers from 2006.
http://www.medizin.uni-tuebingen.de/transfusionsmedizin/institut/eir/content/2006/6/article.pdf
Interleukin-6 (IL6) is a cytokine, a messenger produced by quite a few parts of the body but key ones are muscles and the brain. It has a role in lypolysis (fat break down) it acts as a signal to adipose (fat) tissue. So it plays a part in weight loss and the use of fats rather than sugars in exercise. It also passes across the blood-brain barrier, so IL6 from your legs gets in to your brain.
Its production is not uniform; exercise duration is the key generator for muscle IL6. Exercise intensity has a part to play too. Intense exercise intervals for a period of two hours generates the same sort of levels of IL6 as 4 to 6 hours of longer lower intensity exercise.
Running generates IL6 faster than cycling and over 100 times the background level, but cycling generates a significant amount too. 5 times the normal background level is easy to achieve and this can be as high as 50 times.
IL6 is generated during illness (up to 10,000 time background level), temperature (cold) and exercise can generate up to 110 times background levels. Its production is impaired by blood glucose. Remember these points. IL6 makes exercise harder. This was proven by randomly sampling athletes, injecting IL6 and getting them to run 10k. Those injected were significantly worse performers. So the more there is in your blood the worse you perform at any sport.
IL6 is processed in the brain to produce prostaglandins, these flood your body when you are ill and make it ache. Taking paracetamol reduces the pain caused by prostaglandins. So when you take a lemsip when you have flu you may feel a bit better.
In your resting state, high levels of IL6 are associated with heart attacks.
IL6 background levels fall if you exercise regularly. So you can see how these two may be linked together.
IL6 production declines as the muscles become more efficient when doing the same routine.
IL6 levels peak at around 1 hour after you stop exercising.
IL6 levels are reduced by anti-oxidants, vitamins C and E.
So armed with these facts lets look at some common questions on this forum and see where IL6 may have a role to play. (NB. It does not work in isolation).
Q1: I am doing the same amount of exercise and I have stopped losing weight.
IL6 mobilises the fat store for energy production, your body is more efficient and the levels of IL6 produced have declined, so fat breakdown is not taking place at the same rate. The answer to this is to increase the intensity or duration of exercise to increase IL6, break down the fat and get you to a satisfactory body state/shape.
Q2: I’ve been out and run 18 miles, I had no food or drink during this exercise and I felt ill afterwards, like I had cold or flu, aches. The level of IL6 produced in running is high, no carbs taken means IL6 was even higher (because it was not suppressed). This caused the production of prostaglandins and it makes you feel ill. (Aches, not throw up – sick ).Take a paracetamol and htfu.
Q3: When I swim in the sea, I feel really sleepy tired afterwards unlike in the pool. The exercise and cold temperatures mean your muscles and brain were producing IL6. This caused an increase in cortisol. You need to have 20 mins lie down and shut your eyes, nod off a bit, may be the odd twitch as you fall in/out of sleep. This will sort out the cortisol, serotonin, melatonin and you’ll be fine in no time. If you don’t you’ll feel miserable but not ill. This affects over 40’s more than younger people.
Q4: I bonked a couple of weeks a go now I am flying (Barry Hoban). IL6 production was high when you bonked due to the muscle exhaustion and very low carbohydrates in your blood. Your body has adjusted to this effect, background IL6 is lowered, your muscles are more efficient and produce less IL6 and this effect can last for 3 months or more. Your body is also prepared to break down fats more readily and does not go directly to your carb store, (muscles and liver). So racing or hard exercise seems easier and you don’t depend so much on sugar reserves.
Q5: Does carb depleted training work? Yes. Low carbs = higher IL6 levels. Train carb depleted to artificially increase IL6 levels (ie don’t eat two hours before training and don’t swig on sugary drinks), your training performance will suffer. Background levels of IL6 will fall and muscle production will decrease as in the fat loss case. Race carb loaded to prevent IL6 production and you get a performance increase for the cost of a few jelly babies. Use a carb depleted training regime as your reference, not that one fantastic training session you had when you stuffed your face. If you want fast training sessions and slow races then train carb loaded.
Q6: Should I do long miles if I am only doing short races? Yes, IL6 is produced most effectively by doing long rides 4hrs+, you will benefit from a reduced background IL6 level and lower muscle levels. This can complement higher intensity intervals over a shorter period.
Q7: I feel sleepy tired after a long ride. See Q3.
Here is a meta-study, a summary of a number of papers from 2006.
http://www.medizin.uni-tuebingen.de/transfusionsmedizin/institut/eir/content/2006/6/article.pdf
