The idea that you can improve your ﬁtness by sleeping in an oxygen tent or doing a few breathing exercises in front of Eastenders has always seemed a little too good to be true. New evidence indicates that improving your breathing ability may be more important than previously thought, and that endurance athletes can improve simply by paying attention to their breathing off the bike.
Breathing is about taking in oxygen, to provide heat and energy in the muscles, and getting carbon dioxide out. Crucially though, there are two parts to this process.
1. Firstly there’s the role played by the lungs, which expand to take in oxygen and contract to expel carbon dioxide.
2. Secondly, there’s the role played by the blood, which transports the oxygen from the lungs to the muscles and then carries carbon dioxide back to be expired.
This distinction is crucial because exercise physiology has placed enormous importance on the second part – oxygen transport – and completely discounted the former – the lungs.
The reason is simple. Exercise physiologists showed that training does not alter lung size or capacity and even at maximal intensity humans have considerable breathing reserve. So scientists concluded that the lungs place no limitation on performance and any training that focuses on them solely – as many of the newer breathing exercises do – is ineffectual.
Instead scientists concentrated on oxygen transport, which clearly did beneﬁt from training, and this led to the development of now familiar concepts like VO² max and lactate threshold and the training techniques widely in evidence today.
Altitude training also relates to the oxygen transport system so may have been viewed more favourably by the scientiﬁc community were it not for the fact that while some studies seemed to show a beneﬁt, many simply did not.
Recently though, things have changed. Both these premises – that training the lungs is pointless and training at altitude brings little endurance beneﬁt – are being signiﬁcantly challenged.
Training breathing muscles – the theory
A group of scientists recently took another look at the breathing process and they came to a radical conclusion. They agreed that lung ventilation had no beneﬁcial effect on endurance performance but realised that expanding and contracting the lungs required muscles. These muscles use energy, just like any other, so they reasoned that if these muscles could be trained to become more efﬁcient then performance might improve.
One of these scientists was Professor Alison McConnell of Brunel University. She has spent the last 10 years trying to establish to what degree exercise fatigues the breathing muscles, whether that affects performance and, if it does, by what mechanism. She now believes she has answers.
“When we exercise we work the inspiratory muscles pretty hard and this triggers a reﬂex causing blood vessels in our limbs to constrict,” she says. “We showed this using the calf muscle. Yet after breathing training, the same exercise did not trigger the reﬂex, meaning more blood ﬂowed to the calf and performance improved.”
Training breathing muscles – the evidence
Though some smaller studies still show little beneﬁt in training the breathing muscles, most of the larger studies – which featured cyclists, rowers and runners – agree with McConnell’s conclusion that a small but signiﬁcant improvement is possible.
A team from the State University of New York took 15 competitive athletes and tested whether 30 minutes of daily breathing exercises for four weeks boosted their endurance in a time-trial. It did, by an average of 4 per cent compared to controls. This is reinforced by two earlier studies showing that breathing exercises improved 25km and 40km time-trial performance by 2.5 and 2 per cent respectively.
“I think we have reached a unanimous consensus now,” says McConnell. “The more robust studies, published in better journals, have all found you get a one-off 2-4 per cent performance increase from training the muscles involved in breathing.”
There are two types of breathing devices on the market and each has different devotees. Professor McConnell, who admits to having a vested interest as she helped develop it, favours PowerBreathe, whereas Professor John Leddy, author of the New York study, prefers a device called a Spirotiger.
PowerBreathe employs a technique called hyperpnea, which involves re-breathing expired air. This trains both inspiratory muscles (those involved with breathing in) and expiratory muscles (those involved with breathing out.) Leddy says other devices are like doing weights with your lungs whereas the Spirotiger is like working them on a treadmill, which for endurance athletes makes more sense.
Unfortunately the Spirotiger will set you back around £400 and it might need to be shipped in from abroad. McConnell reckons PowerBreathe, which costs from £27 and is widely available, is just as effective.
“No study shows beneﬁt in training the expiratory muscles,” she says. “We’re not sure why – maybe they don’t trigger the reﬂex that constricts blood vessels. So using hyperpnea is like taking a sledgehammer to crack a nut.”
McConnell recommends doing 30 breaths twice a day for four to six weeks in a relaxed position, and then, once this feels relatively easy, to do the same in the aerobar position so that the lung muscles get used to working in the squashed state that we place them in while riding.
Altitude training – the theory
Air at altitude is thinner, so for the same volume, breathing at altitude brings in fewer molecules of oxygen than at sea level. Less oxygen is available to bind to the red blood cells which transport it to the muscles, so exercise feels harder. The body adapts by releasing the hormone erythropoietin (EPO), which stimulates production of red blood cells, making the oxygen transport system more effective and improving endurance.
“Making more EPO is one way it works,” says Richard Pullan, a breathing expert and founder of the Altitude Centre, an altitude training company. “It also creates more capillaries to deliver oxygen to the muscles and makes cell membranes more receptive.”
This has been related to training in different ways. One approach is to train at altitude so the system becomes more efﬁcient. Another is to ‘live high, train low’ (LHTL), which involves training at sea level but spending the rest of the time breathing thinner air. Some also champion intermittent hypoxic training: alternating between breathing normal air and hypoxic (low-oxygen) air. Altitude training is also used for acclimatisation and some claim it’s a useful tool when recovering from injury.
Altitude training – the evidence
The evidence on altitude training increasing red blood cell mass is mixed, but as with the breathing exercises, it is tipping towards the positive. Proponents say the beneﬁts were masked in some studies because, with such little oxygen, the athletes had a reduced ability to train hard, hence the development of LHTL, which has greater support.
Two studies at the Swiss Federal Institute of Sports found increases in red blood cell mass when employing the LHTL strategy. Several other studies have shown concrete beneﬁts from intermittent hypoxia. But there are still enough negative studies to cast doubt. A team from the Australian Institute of Sport had 13 cyclists, triathletes and cross-country skiers sleep in an oxygen tent for 23 nights and found no effect at all. McConnell is one of those who remains unconvinced.
“The jury is still out,” she says. “The evidence for improving red blood cell mass is equivocal at best. However, newer studies suggest that it may beneﬁt cycling economy, but we don’t fully understand the mechanism yet.”
These days you don’t need to travel to a high altitude destination to get the beneﬁts of training in thinner air. Gyms like the Altitude Centre in Covent Garden have special high-altitude rooms containing exercise bikes, treadmills and other equipment.
“My aim is to make facilities previously available only to top athletes open to the general public,” says Pullan. “Everyone acclimatises differently to altitude so improvements will vary from person to person, but I strongly believe everyone can beneﬁt.”
Because the facilities are local doesn’t mean they’re cheap. Following an initial £79 consultation, a single session at the Altitude Centre will set you back £40 and Pullan recommends top-level cyclists altitude train twice weekly.
Adopting the LHTL strategy might hurt your wallet even more, as oxygen tents retail at around £1000. To give intermittent hypoxic training a try you’ll need a portable device which allows you to breathe thinner air in between bouts of regular air. These cost around £500 to hire or £3500 new.
Yoga and pilates – the theory
There’s more to yoga and pilates than just breathing, and many, like time-trialler Helen Gorman (see below), have found them beneﬁcial for strength or injury rehabilitation. But some believe there may be a performance beneﬁt simply by learning slow breathing, something yoga and pilates emphasise.
“This is because of the Bohr effect,” says Pullan. “When carbon dioxide levels are raised, red blood cells release oxygen better. By slowing down your breathing, you retain carbon dioxide, meaning more oxygen is released.”
Yoga and pilates – the evidence
Unsurprisingly there have been few studies relating the breathing element of yoga and pilates to exercise performance. However, there is evidence that yogic breathing eases the symptoms of asthma and researchers have also found a beneﬁcial effect on mood and relaxation, which could help before and during a race.
However, several studies have shown that slowing down breathing has little effect on lung function or anything else.
“I’m not aware of any evidence which would indicate a speciﬁc improvement in exercise performance from yoga,” said McConnell. “But there’s no doubt that it can provide control and conﬁdence in breathing and it plays a postural role too. I’d say it’s not an alternative to breathing exercises, but a useful complement.”
Although you might want to attend a class to get the full beneﬁt, this really is a breathing exercise that you can do in front of the television without spending a penny! According to Pullan, the ﬁrst step is to become aware of how you breathe. Ideally you want to breathe deeply through your nose so that your belly goes up and down rather than your chest.
“We are the only land mammal to breathe through our mouths,” Pullan says. “The nose is so much better. It ﬁlters out unhelpful particles, humidiﬁes and warms the air to body temperature and produces nitric oxide which opens air sacs in our lungs.”
Once you’ve mastered this, the next step is to try to slow your breathing down by registering the number of breaths per minute. “This is a great thing to do before a race,” says Pullan. “It’ll open up your capillaries, meaning you’re really ready to go as soon as the gun ﬁres.”
Consulting the althletes
Pro Pilates: Helen Gorman, Time-trialler and former GB swimmer
Helen doesn’t need to be convinced of the importance of breathing, even now she’s swapped the pool for a bike. The 35-year-old, keen to improve her time-trial times and to stave off an Achilles tendon injury, regularly performs yoga and pilates to help. However, when asked whether she believes there is a direct link between breathing and endurance performance, she is unsure.
“I’ve never really applied the breathing element to cycling. I know I would beneﬁt by thinking about it more, but I just enjoy riding my bike. There’s no doubt that the exercises have helped with my injury though and you can’t do them properly without getting your breathing right.”
Gorman used to do regular lengths of underwater swimming to help train her to relax even when starved of oxygen. She thinks yoga and pilates serve a similar purpose, and training her breathing has helped her stay calm during racing.
“There is a meditative element which is very relaxing, especially if you’re tired after a long ride at the weekend,” she says. “You have to concentrate solely on activating the right muscles. I think learning to breathe more deeply and to integrate your breathing with the rhythms of cycling probably is beneﬁcial.”
High Flier: Justin Shevlin, Triathlete
Justin Shevlin, 36, admits that he will try anything if it gives him a competitive edge, and he’s recently turned to both PowerBreathe and altitude training in order to boost his endurance. While he feels that both have been beneﬁcial in different ways, he’s in no doubt which worked best.
“From the minute I started altitude training I could feel the effects within three days,” he says. “PowerBreathe was good but though it only takes a few minutes it’s quite an effort and seemed to take longer to work, whereas with the altitude training you just feel so much more energised and efﬁcient straight away, like taking a short cut.”
Convinced, Shevlin has been regularly training in thinner air and is about to embark on a 10-day spell of sleeping in an oxygen tent. He says he’s already over a minute faster on one of his regular sessions: three-mile reps.
He admits that altitude training may beneﬁt him particularly because he previously suffered from exercise-induced asthma, but he also believes everyone will get something out of it, because of the way it reduces perceived exertion.
“When training at altitude your lungs start screaming at you immediately, so when you return to normal the difference is amazing – it feels so much easier!”