Masimo MightySat™ Pulse Oximeter Protocol
by Johnathan Edwards MD*
Pulse oximetry is a safe, effective noninvasive method for athletes to measure their own oxygen saturation in a convenient location. Peripheral oxygen saturation or SpO2 has a good correlation to the state of oxygenation in the arterial blood system in humans. It is in fact our arterial blood system that delivers blood to our muscles and organs which defines the capabilities of our athletic endeavors. Pulse oximetry measures the ratio of red to infrared light absorption of pulsatile blood flow. Until recently, the pulse oximeter was reserved for medical use focusing on respiratory care, but with scientific advances, this device is accessible to everyone and it has specific uses in the optimization of athletes.
Core Benefits of the MightySat Pulse Oximeter for the Athlete
- Autonomic Nervous System bio-feedback is very important for the athletes
- Breath holding exercises – the athletes can see in real time how the SpO2 and heart rate responds and can visually appreciate the SpO2 optimizing with their breathing techniques
- Curiosity – every athlete is curious about how their body is doing, and this affects confidence
- Develops an understanding how the athlete’s SpO2 can change from day to day and be able to make decisions based on the values observed
- Guides workouts, intensity, and recovery
- Individualizes the “recovery story” of an athlete’s physiology
- Optimal oxygenation and hydration during different situations – sea level, altitude, fatigue
- Removes the guess work out of altitude training
- Visualization of the SpO2, pulse wave, pulse index, and PVi
Pulse Oximetry in Athletes
Pulse oximetry is a valuable tool for any athlete competing in a multitude of sports to guide them through health and training decisions. Athletes, using pulse oximetry to guide daily training and living activities, are going to have a distinct advantage over those who do not because knowing that something is not going in the right direction before it becomes a problem is essential to prevention of overtraining, undertraining, or to maximize performance. Monitoring oxygenation can function as a spot check for athletes to know that they are capable of having a really good training session, or if they are not hitting their training goals, a direction to the reason why. The pulse oximeter and the other paramaters of the MightySat pulse oximeter can be used as tool to maximize performance. The reward is that it may pay off just before or at a crucial sporting event. Finally, it is a great feeling for the athlete to know what is going on inside of the body.
Use of oxygen measurements can give the athlete confidence that the body’s physiology is doing well and that nothing has changed. Having the confidence that everything is going as planned can be as valuable as actually training.
Knowing the body is optimally oxygenated gives a mental edge to an athlete that everything is going as well as possible.
Plethysmography Variability Index
PVi or Pleth Variability Index is a tool unique to Masimo pulse oximeters. PVi is a valuable tool that can be used to help assess hydration status, especially in moderate to severe dehydration.
Low SpO2 can signal the athlete to modify training and / or to seek medical evaluation.
The PVi can be used to help guide hydration and decisions to be more or less aggressive in hydration strategies as it may relate to training and performance.
How I Educate My Athletes To Use The Masimo MightySat Pulse Oximeter
Breathing exercises that develop carbon dioxide retention tolerances are valuable for many reasons to an athlete. Consistent practice of breathing exercises can increase resistance to low oxygen / high carbon dioxide states, exercise the accessory respiratory muscles, produce a release of nitric oxide and provides a short period of meditation and reflection. I try to focus on the practical mental and physiologic components of breathing exercises, using a tool that is practical anywhere and anytime. The advantages of having the athlete use the MightySat pulse oximeter for these exercises:
- The athlete has an initiative to use the pulse oximeter each morning.
- They need the pulse oximeter to watch the SpO2 and heart rate along with the exercise.
- A visual monitor to follow the extremes of their SpO2 and heart rate.
There are many high quality, legitimate studies showing the benefits of breathing exercises. It’s no secret that a well-functioning immune system protects the body from pathogens, which can reduce an athletes performance, but sometimes the immune system is not strong enough by itself. The immune system is controlled by the autonomic nervous system, and it has long been thought that we could not voluntarily influence our immune system nor the autonomic nervous system. Recent studies have shown that humans do indeed have the potential and ability to influence the autonomic immune system (ANS) with the power of the mind.
Every morning, I have my athletes drink a cold glass of water and note their baseline values from the MightySat pulse oximeter. In a comfortable position, I have them start their routine breathing exercises. They execute full, controlled, rapid breathes for a 20 to 40 count. Usually, there is a feeling of light headedness or tingling in the extremities, and, once this is achieved, I have the athlete continue the breaths until the SpO2 reads 99 or 100%. This teaches them the correct breathing techniques that optimizes their oxygenation. Once they comfortably reach a satisfactory SpO2, I instruct them to fully exhale and hold their breath using a timer. While they are in a breath hold, there should be no urge to breath. This is a time for reflection and meditation as well as mentally “scan” their bodies while not having any urge to breath. During this time the SpO2 should remain at 99 or 100%. Normally, when 90 to 120 seconds pass, the heart rate and SpO2 will progressively decrease. And I instruct them to not panic and just go with it. Once they feel a tingling or urge to urinate (nitric oxide release), I tell them to start reciting the alphabet and hold respiration until it feels uncomfortable. Usually, the SpO2 is decreased to less than 60%, and I have even seen it drop to 40% at times. The heart rate often drops to 25 to 35 beats per minute in some people. Athletes often report being able to breath freely and open after the exercise. They also report an intense moment of mental clarity afterwards. I usually suggest repeating the process 2 to 4 times a day and even more if they are fatigued or feeling sick.
There are many points to highlight that are useful for the athlete:
- The athlete will become accustomed to how their SpO2, heart rate, and breathing are interconnected. Essentially learning how to control their ANS.
- The athlete will notice subtler changes in their physiology and be able to make better decisions about their training and recovery.
- After months of training, the breathing exercises and the use of the MightySat can provide the athlete with a trend that can tell them how their body is responding to various training stresses.
- There is a feeling of empowerment, in that the athlete can do something about their situation on their own, at their convenience, and not have to depend on someone else to gauge their situation.
When racing or training at altitude, it is very important to know how the body is responding to the increase in elevation. Certain physiologic processes such as an increase in nitric oxide and production of Hypoxia Inducible Factor (HIF) from the kidneys and liver to optimally stimulate their bone marrow in producing more red blood cells with the goal of enhancing their performance. There is also an adaptation within the red blood cells themselves.
I instruct the athlete to be note the SpO2 before and after training. They can use the pulse oximeter along with the breathing exercises to optimize their oxygenation. Again this may be helpful in maximizing performance, which often occurs at higher altitudes. Knowing that the body is acclimatizing properly can be a big mental relief to an athlete. Because every athlete knows, that there is a chance the acclimatization may not be effective or may not peak at the desired time. Being able to know the body is resting at a lower SpO2 can be a big confidence booster for the athlete.
Low Oxygen Interval Training
The pulse oximeter is useful to monitor SpO2 during training in low oxygen or hypoxic environments. It is useful for the athlete to see how their SpO2 decreases with hypoxic efforts. It gives them feedback, increasing their confidence that they are performing the correct exercises and that their equipment is functioning properly.
I also have the athlete periodically check their SpO2 while training longer sessions at zone 2 using low oxygen environments. This helps them adapt to lower SpO2 levels while exercising. For example, they may hold 60% of their FTP under hypoxic conditions. The target SpO2 might be 90%, so they need the pulse oximeter to direct their training and know their SpO2 level.
Using a pulse oximeter on race days is an individual choice for the athlete. It is a great tool to make sure that everything is status quo and that the athlete is optimally oxygenated. I advise using the pulse oximeter after each race or event to know where their body’s rhythm lies. And with the technology of the Masimo MightySat, the ability of helping asses one’s hydration status can be invaluable.
A Low SpO2 Reading
There are many reasons an SpO2 reading can be low, but the first thing I teach an athlete is to not panic. A SpO2 reading is not meant to be taken alone and must be taken along with other vital signs to build an accurate picture of where the athlete’s physiology lies. If there are other signs of fatigue along with the low SpO2 reading, then it might be wise to decrease the training load and / or optimize recovery protocols and seek medical consultation. A low SpO2 associated with a decreased breath hold may signal a decreased lung capacity or acid base imbalance, especially if the athlete has been training in highly polluted environments or has a respiratory infection. The PVi as well as other factors should be taken into consideration. The PVi can guide hydration and decisions to be more or less aggressive in hydration strategies as it may relate to training and performance, especially in times of severe dehydration.
Race/Game Day Routine
Every cyclist has a protocol of breathing at the start gate to optimize their oxygenation as they start a time trial. Starting a time trial well is crucial to the confidence to the athlete and can often dictate how the rest of the event will go. Knowing your lungs will be clear before an event is crucial and performing breathing exercises is a perfect way to achieve this. This system or protocol can be used at the start line, start gate or at the beginning of any sport’s competition, race or game.
* Dr. Edwards is a paid consultant for Masimo Corporation