Friday Tidbits #7: 4-7-8 Breathing & more
Welcome to Friday Tidbits. This is a very short email with morsels of information to help you tweak your life and health for optimum longevity and healthy ageing.
15 Dec 2023
Breathing & Stress
The 4-7-8 breathing technique is referred to the “natural tranquilizer for the nervous system” - Dr Andrew Weil.
How to do it: inhale for a count of 4 - then hold your breath for a count of 7 - then exhale for a count of 8. Start with 6 rounds of breath. Increase to a total of 5-10 minute. Watch the video by Dr Andrew Weil or on my channel.
Similar to most breathing techniques used for relaxation, nasal breathing is encouraged. Some people may find the slow exhale difficult. If this is the case, it may help if you pretend to blow out candles on a birthday cake or use a hissing exhale, trickling the air out through the teeth.
The 4-7-8 breathing control aims to reduce anxiety and help to fall asleep faster 1.
Vierra et. al 2 investigated the effect of sleep deprivation and 4-7-8 breathing on 42 participants. Half the group was subjected to sleep deprivation. It goes without saying that lack of sleep is not good for mental and physical health and performance. Both groups completed 3 sets of 4-7-8 breathing for 6 cycles. The study found an improvement in HRV after participants in the Heart rate and blood pressure decreased in both groups.
The 4-7-8 technique improve autonomic nervous system regulation by increasing parasympathetic activity. This signals the brain to calm the body down and improve physical response to anxiety.
Sleep
Your early morning phone habit is ruining your sleep.
Many of us reach for our mobile phone within minutes of waking. After checking for “urgent” messages, we check on what we might have missed on social media - Instagram, TikTok, Facebook and a multitude of others. Every few seconds, we get new and exciting entertainment. In fact, your brain anticipates the stimulus and this makes scrolling so addictive.
Have you ever experienced the worst sleep the night before a new or exciting event? It feels like you have not been asleep at all. You wake every hour checking the alarm clock. Perhaps you needed to catch an early morning flight? Or have to get up early for an exam or work meeting?
Part of this phenomenon is the anticipatory effect of the neuromodulator, dopamine (3). When you are looking forward to something, dopamine is released. Dopamine is called the “molecule of more” and it drives our behaviour to chase the reward. Your brain predicts that something good is going to happen, this motivates your behaviour and you get “rewarded” by the outcome 3. If the outcome is as good as you predicted, you feel great. If the outcome is not as good, then you feel disappointed and keep chasing the next possible reward.
Help!
The advise I often give to my clients is to cut the ties - slowly. And it will be painful. Start by waiting 15 minutes after waking before you pick up your phone. Increase the time by 15 minutes every week, aiming for 1-2 hours.
In the words of one of my clients, Nic:
“Delaying my phone habit improved my sleep and anxiety more than anything else. My brain fog is also gone.”
Movement
Exercise in hot conditions can tank your performance - especially if you are not used to it.
“Duh!”
The 2020 Olympics in Tokyo was predicted (and turned out to be) very hot. To test the effect on performance de Korte et. al tested 106 Dutch elite athletes under control conditions of 16C with 55% humidity and 48 hours later in 32C with 75% humidity 4. Athletes exercised on a cycling ergometer at 70% of maximum heart rate for 20 minutes, after which the power output (watts) were increased by 5% every 3 minutes, until exhaustion. They found that time to exhaustion in the hot environment decreased by ~16 minutes, equating to a decrease in exercise performance of 26 +/- 11%. Endurance athletes experienced a higher increase in core body temperature and sweat rate compared to power and skill based athletes. Notably, there are large variations between individuals.
But what exactly is the reason?
Most research show that maximal oxygen uptake by muscles is reduced hot environments - VO2max is lower by 0.25 L/min 5. The theory is that the thermal stress leads to a higher proportion of blood flow to the skin surfaces. Skin blood flow can be as much as 7 L/min during maximal vasodilation. The skin blood vessels become engorged and blood pools in the skin, especially in lower limbs. Basically, your legs feel like lead. Blood volume and cardiac filling is reduced leading to cardiovascular strain.
With more blood at the skin surface, less blood is sent to contracting muscles per given cardiac output. Unsurprisingly, muscles have to rely more on anaerobic metabolism. Another factor is the vasoconstriction to liver and kidneys during exercise, which reduce the ability to remove lactate from the blood stream.
Thermosensors in the skin and body sense the rise in temperature and sends this information to the brain’s thermoregulation centre. In response, you sweat and more blood flow is directed to the skin surface. When sweat evaporates, it cools the skin surface and this cools the blood flowing near the surface. The cooled blood is sent back to the heart to be redistributed to deeper tissues. Sweat rates are highly variable between individuals, ranging 1-11 litres per 24 hours. In prolonged high intensity exercise 1 litre per hour is common, but can be as high as 3.7 litres. Sweating can lead to dehydration if fluid is not replaced. This reduce the total blood volume, making the blood more sticky. And this reduce sweat rate - to preserve blood volume - and the ability to dissipate heat is lowered, core body temperature rises.
During exercise-heat stress, competing metabolic and thermoregulatory demands for blood flow make it difficult to maintain an adequate cardiac output. Evidence show that acclimatised athletes perform better.
References:
Russo, Marc A et al. “The physiological effects of slow breathing in the healthy human.” Breathe (Sheffield, England) vol. 13,4 (2017): 298-309. doi:10.1183/20734735.009817
Vierra, Jaruwan et al. “Effects of sleep deprivation and 4-7-8 breathing control on heart rate variability, blood pressure, blood glucose, and endothelial function in healthy young adults.” Physiological reports vol. 10,13 (2022): e15389. doi:10.14814/phy2.15389
Nagano-Saito, A., Cisek, P., Perna, A. S., Shirdel, F. Z., Benkelfat, C., Leyton, M., & Dagher, A. (2012). From anticipation to action, the role of dopamine in perceptual decision making: an fMRI-tyrosine depletion study. Journal of Neurophysiology, 108(2), 501-512. https://doi.org/10.1152/jn.00592.2011
de Korte, J.Q., Bongers, C.C.W.G., Hopman, M.T.E. et al. Exercise Performance and Thermoregulatory Responses of Elite Athletes Exercising in the Heat: Outcomes of the Thermo Tokyo Study. Sports Med 51, 2423–2436 (2021). https://doi.org/10.1007/s40279-021-01530-w
Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations. Washington (DC): National Academies Press (US); 1993. 3, Physiological Responses to Exercise in the Heat. Available from: https://www.ncbi.nlm.nih.gov/books/NBK236240/