Published on January 22, 2016
The Caffeine Guide for Runners
Caffeine is one of the oldest drugs known to man and in many guises – from a shot of espresso to a caffeinated gel – is the go-to choice of many endurance athletes. Beyond its well-recognised stimulant effects there are a host of other pros and cons to this seemingly simple pick-me-up; RunningMonkey poured a mug of java and dug through the evidence. But, first here’s a run down on caffeine levels from common sources – note that caffeine levels in espresso shots can very enormously.
Caffeine Increases Lactic Threshold?
The idea that caffeine can ‘up’ the lactic threshold – the point at which, to be simplistic, you feel the ‘burn’ in the muscles – is often cited by endurance athletes as a benefit. Most research actually shows that what is more likely happening is that caffeine helps regulate (in practice, slow down) the rate at which the muscles consume glycogen, therefore allowing you to go for longer before the muscles are fatigued with lactic build-up. Possibly pedantic when the net result is the same, but that seems to be the case and it’s known as ‘glycogen sparing’. The University of Illinois found in a 2009 study that 300mg of caffeine (around four cups of espresso) reduced the amount of ‘burn’ felt by its test subjects. More on the research here.
Caffeine Leads to High Blood Pressure?
Yes and no. Caffeine does cause short-term (and really quite dramatic) spikes in blood pressure although researchers argue as to why. One camp goes with the idea that caffeine blocks a specific hormone responsible for helping arteries stay healthily wide; another suggests that caffeine stimulates the adrenal gland and prompts an increase in adrenaline (and subsequently BP.)
On the plus side most data suggests there’s noting to indicate that caffeine causes long-term problems with blood pressure. Following meta-research in 2005 German medical journal Therapeutische Umschau concluded: ‘no clear association between coffee and the risk of hypertension, heart attack, and other cardiovascular diseases was found…’
Caffeine Helps Fights Free Radicals?
The body produces free radicals as a result of using oxygen to produce energy, these cause damage to DNA, molecules and tissues. Fortunately, amongst other mechanisms, the body’s natural antioxidant defences ‘fight’ the free radicals. This can be boosted by plant-based foods rich in their own antioxidants. Coffee is a plant, so you can see where this is going…
Coffee actually contains over 1,000 natural substances called phytochemicals (‘phyto’ comes from the Greek for ‘plant’) and many of these are antioxidants that help protect against cell damage caused by free radicals. In a 2011 study Jorge Rafael Leon-Carmona of the Universidad Autnoma Metropolitana-Iztapalapa, Mexico, identified the mechanism by which caffeine’s antioxidants react with free radicals as something called the ‘radical adduct formation’ (RAF). Details of Leon-Carmona’s research here.
Caffeine Improves Awareness and Memory?
If this is the case this could certainly benefit more ‘strategic’ runners when it comes to besting the competition. Amongst other research into this area, Josep M. Serra Grabulosa, from the Department of Psychiatry and Clinical Psychobiology at Universidad de Barcelona has suggested that caffeine in combination with glucose is particularly affective. Potentially making a sugary coffee or caffeinated gel a great way to boost mental agility on the run.
The research, published in Human Psychopharmacology: Clinical and Experimental, reported that volunteers who drank caffeinated coffee in the morning performed better than non-coffee drinkers in tests that involved learning new information. An earlier study, by the same research team, on the effects of caffeine and glucose consumption showed improvements in attention span and long-term ‘declarative’ memory. Read more on the research here.
Caffeine increases VO2Max?
Research seems to constantly flip-flop on findings when it comes to this. An athlete’s VO2 max is a measure of the maximum volume of oxygen that can be taken up by the body; it’s measured in millilitres per kilogramme of body weight per minute (or ml/kg/min). Basically the bigger the VO2 max, the better.
Whilst a 2006 report in the International Journal of Sport Science indicated ‘non-significant modification in VO2 max’ another study from the University of Guelph in Ontario, Canada tells another story. Here researchers noted that tests: ‘…showed that ingestion of caffeinated coffee decreased the time taken to run 1500m, increased the speed of the ‘finishing burst’, and increased VO2 during the high-intensity 1500m run.’
Even those that appear to advocate the effectiveness of caffeine on VO2 max seem to conclude that the mechanisms by which it does so remain elusive.
Caffeine Can Contribute to Osteoporosis?
Strong bones are obviously important to runners (and most other people, natch) so anything that can contribute to the likes of osteoporosis is a problem. Unfortunately there’s plenty of research to suggest that caffeine does potentially do just that by leaching much needed calcium from the bones.
Linda K. Massey, a professor of human nutrition at Washington State University notes that: ‘you lose about 6 milligrams of calcium for every 100 milligrams of caffeine ingested.’ 100mg is roughly 1.5 cups of espresso, but the good news is that 6mg of calcium is only a tiny percentage of the 800 – 1,000mg that a healthy diet should be providing anyway.
Those that are at greater risk of osteoporosis may be best advised to avoid over caffeinating their day and many runner’s already fortify with calcium and vitamin D supplements. Massey concludes: ‘limiting caffeine intake to 300 milligrams a day, while getting adequate calcium, probably offsets any losses caffeine causes…’
Caffeine ‘Speeds Up’ Painkillers?
Sorry but this is another one where the jury is somewhat out. But that said it’s the main reason why caffeine is frequently found in over the counter cold and flu remedies.
However Sheena Derry, a senior research officer at University of Oxford, oversaw a review of some 19 studies covering 7,238 subjects. Looking mostly at painkillers acetaminophen and ibuprofen the review concluded: ‘Combined results from all the studies showed that the groups of patients randomized to take pain medicine that included caffeine had a significantly larger proportion of individuals who had a good level of pain relief.’
As with (possible) VO2 max improvements the mechanism by which caffeine might help in combination with painkillers remains largely unknown. The whole debate is further complicated by the fact that pain – and relief from – is really perceived rather than something that can be easily measured.
More on Derry’s findings, reported by the Center for Advancing Health, here.
Caffeine Causes dehydration?
This is certainly one of the things that most people seem to believe to be true. It really isn’t. Caffeinated drinks like cola and coffee do have a mild diuretic effect (meaning they cause you the need to pee) but that’s not enough to cause dehydration alone. Even if a runner is ingesting caffeine via gels, they would normally be doing so in conjunction with a hydration strategy for their training run or race.
In research carried out by the School of Sport and Exercise Sciences, University of Birmingham, no difference in hydration / dehydration levels were found between subjects drinking water and those drinking caffeinated drinks. Granted the research was funded by the Institute for Scientific Information on Coffee, which is made up of seven major European coffee companies, but there’s plenty of other evidence to back up the claim. Even the exceptionally well-respected Mayo Clinic notes: ‘Drinking caffeine–containing beverages as part of a normal lifestyle doesn’t cause fluid loss in excess of the volume ingested.’
So, Caffeine – Good or Bad?
Perhaps the slightly boring (if reassuring) conclusion is that caffeine, in moderation, is going to do little harm and may do your running some good. A quick boost pulling an all-night run though the medium of coffee looks to be no bad thing and a daily cup or two is going to do less harm than a sugar-laden soft drink.
Before RunningMonkey leaves you to go brew a big jug of Joe you might like to take a look at the useful caffeine comparison list at caffeineinformer.com
Please note: this feature is intended as a guide only and information on caffeine and its consumption shouldn’t be taken above that given by your healthcare professional (in other words, RunningMonkey isn’t responsible for what you put in your body…)