Caffeine sensitivity

As wearable technology is improving, and becoming more easily accessible, you are provided with new opportunities to improve your overall health and well-being using feedback from wearable technologies, such as smart watches and rings.

Sleep is likely the most prevalent biomarker measured by wearable technology, and can provide a substantial degree of insight as to how your nervous system is responding to caffeine. While you should initially start with a qualitative self assessment of how recovered you after a night of sleep, you can also use the data provided from wearable technology to better determine your sleep patterns and quality. Thus, when manipulating different variables of your daily routine, such as a different schedule or volume of caffeine, you can determine if a specific implementation of caffeine has any effect on yoir subsequent ability to recover.

The most optimal wearable devices will measure the quantity and quality ofbyour sleep by reporting the aggregate total of sleep, and the time spent in each stage of sleep (light, deep, and REM sleep). You can then Intuit your baseline sleep duration and quality in the absence of caffeine, and compare the statistics when you begin to introduce caffeine in different dosages and methodologies. A large reduction in the volume of deep, REM, or overall sleep, if time spent in bed remains constant, would indicate caffeine is impairing your sleep quality, thus hindering your ability to recover.

If a specific protocol of caffeine improves your physical performance during a workout, but repairs recovery, it may be a viable protocol to employ during a when it is absolutely necessary, but it will inevitably harm your fitness improvements following a workout by impairing your ability to truly adapt to a workout. Adaptation to a novel stressor is the mechanism by which your fitness improves. In a scenario in which a protocol is detrimentally affecting your sleep, there are two major variables that you can manipulate in an attempt to fix sleep disturbances: the timing of caffeine ingestion, and the overall quantity of caffeine. You can reduce the quantity of caffeine you are ingesting, you can terminate further ingestion of caffeine earlier in the day, or you can do both.

Heart rate variability is another quantitative measure to determine how caffeine is influencing you physiologically. Heart rate variability is the variation in the speed of one's heart beat.(de Oliveira, Rackel Aguiar Mendes, et al. ) Heart rate variability is used to quantify the amount of activity from both our sympathetic, and parasympathetic nervous system. The heart rate variability measurement can provide information that can help conclude the efficacy of anstimulant, such as caffeine, and what it's impacts on your fitness and recovery entail. If your Heart rate variability over the course of a day is high, it is indicative that you can both properly elevate, and downregulate your heart rate and arousal. Moreover, if your heart rate variability increases over a period of time, it indicates that your fitness is improving.

Conversely, if you are insufficiently recovering after a workout or event, your heart rate variability will likely decrease, indicating you have a higher resting heart rate due to insufficient rest. Understanding your heart rate variability fluctuations allow you to interpret if caffeine is increasing or decreasing your health. If your heart rate variability begins to decrease in response to caffeine ingestion, it would be in your best interest to alter your current method of caffeine use, and manipulate the variables previously mentioned, to decrease the unintentional effects of the stimulant.

Despite the general accuracy of heart rate variability, one can further benefit from a more in depth examination of their daily nervous system habits if they have the ability to access their low frequency to high frequency ratio. If one's heart rate remains elevated at rest, it will likely impede on their ability to maximally recover from a physical effort. An elevated low frequency heart rate score indicates that an individual is spending an inordinate amount of time with an elevated heart rate, which is typically correlated with high arousal. The low frequency number within heart rate data corresponds to an athlete being in a state of high sympathetic nervous system activity and dominance. Similarly, the high frequency data corresponds with an athlete being in a state of high parasympathetic nervous system activity. You can purchase a technology that will provide feedback as to how much time you are spending within each heart rate zone. If you see the ratio of low frequency activity trending upwards in correlation to caffeine intake, one can assume they have an imbalance of nervous system activity.

If you have the equipment to do so, you can greatly benefit from exploring your subjective feelings, and your objective data when implementing caffeine to determine a dose that will induce maximal benefits. In terms of HRV, the most optimal use of caffeine would allow an athlete to increase their HRV without impeding on your ability to recover from the increase in workload.