Tour de France 2019 is a gruelling event. The 21 stage race begins on the flat. But this isn’t for long. The race winds its way through flat, hilly and finally mountainous terrain. This year, we now know, is one of the most demanding Tour de France races. It includes 7 mountain stages with 5 mountain-top finishes. Because the seven mountain stages climb above 2,000 metres, it is one of the highest Tours for many years. This adds another challenge for the riders, that of breathing at high altitude. This is particularly challenging for riders of the 2019 Tour, as the highest point in the race, the Col de l'Iseran mountain pass has an altitude of 2,770m.
Breathing at high altitude
As a cyclist climbs to high altitude breathing increases. This happens automatically. The reason for this is because the body is responding to less oxygen in each breath. As a result, ventilation increases as they try to increase oxygen uptake. However, in spite of an increase in breathing, less oxygen will reach the working muscles, such as the legs. This is because signals are sent to the nervous system telling it to redirect oxygen from the legs to the diaphragm in order to keep up with breathing at altitude. Consequently, the cyclist’s leg muscles begin to suffer from fatigue. Inevitably, this affects performance.
Effects of high altitude breathing
Breathing harder and quicker is an automatic response to the fall in air pressure. In addition to this, the heart works harder too. It does this to try and increase the flow of oxygen-carrying red blood cells to the lungs. It’s a desperate bid to ensure the lungs don’t ‘steal’ the oxygen-carrying red blood cells from straining muscles.
In this article, 2018 Tour de France winner Geraint Thomas says,
"You just can't do the same powers that you do at sea level… It is just like a thinner sort of air, really, up there. You can just tell, like, when you're breathing, you're just not getting quite as much oxygen in the lungs as you normally would."
Another consequence of the challenges that breathing at high altitude inflicts on the body, is that of greater quantities of lactic acid. Cycling at altitude requires intense power and energy to climb the hills. But the body's response to trying to produce energy with less oxygen is to produce larger amounts of lactic acid. It’s the build-up of lactic acid in the muscles that causes that feeling of ‘muscle burn’. It’s also responsible for slowing a cyclist down as it reduces the muscles ability to function.
Active.com explain that lactic acid is the end product of anaerobic metabolism. It says that a build-up of lactic acid occurs when there is insufficient oxygen to produce the energy required by the exercise. Furthermore, they say that when a very high level of work is reached, as in the Tour, lactic acid production becomes constant. As a result, the cyclist will experience acute muscle fatigue.
Preparing for the challenges of breathing at altitude
This 2019 Review Article in Frontiers in Physiology investigates the use of respiratory muscle training (RMT), including inspiratory muscle training (IMT) with POWERbreathe, for acclimatising to the altitude. The review provides evidence that such training,
“…has the potential to minimize at least some of the limiting factors related to the respiratory system occurring during training / competition at altitude / in hypoxia.”
It goes on to suggest the expected benefits may include:
- A delay in the onset of premature fatigue.
- A delay in respiratory muscle metaboreflex onset/activation.
- An improvement in clearance and tolerance to anaerobic metabolite products.
- A decrease in the perception of dyspnea (‘air hunger’).
- An increase in oxygen saturation values.
- A more favourable blood redistribution to the locomotor muscles.
Recovering from high altitude breathing problems
By incorporating breathing exercises for high altitude before the Tour de France or Giro d’Italia, cyclists will cope better with the challenges of breathing at high altitude. Inspiratory Muscle Training, such as with POWERbreathe, increases the strength and stamina of the breathing muscles, reducing breathing fatigue. Even better would be to perform IMT during turbo training. This will target the inspiratory muscles in the hunched position the athlete will be in during cycling.
Recovering from high levels of lactic acid
For cyclists in the Tour de France and Giro d’Italia an IMT recovery session is proven to be beneficial as it:
- Will ensure that fatiguing inspiratory muscles won’t redirect blood flow from the working muscles to the breathing muscles. This will preserve limb blood flow and reduce reliance upon anaerobic metabolism.
- Will increase the aerobic capacity of the breathing muscles, making them more efficient lactate consumers during and after exercise.
Research shows that breathing against a small inspiratory load immediately after exercise reduces lactate by 16%. It also reduces lactate as soon as exercise finishes, unlike traditional active recovery which may take 5-minutes to clear lactate. Another bonus for Tour de France and Giro d’Italia riders is that subsequent research demonstrates a post-exercise inspiratory resistive loading (after a Wingate test) reduces post-exercise effort perception and improves peak power on subsequent all-out maximal-intensity exercise. This is obviously beneficial when riders need to perform at their best, day-after-day.