The Wild Health Take: Week 10
Each week Dr. Carl Seger listens to your favorite podcasts to summarize the data and give you our precision medicine take. Here's this week's take:
Who: The DRIVE w/ Peter Attia, MD
What: #218- AMA #38: Can you exercise too much?
- On The DRIVE podcast, there have been many different opinions on exercise, including topics like minimum effective dose and the most effective exercise. Challenges exist in trying to point to the minimum effective dose and optimal dose of exercise because so many factors play a role, including individual activity level and lifetime experience with exercise. For example, people who currently do zero physical activity have the highest mortality risk. Still, with even the slightest increase from zero exercise to light movement, a 20-25% reduction in all-cause mortality has been shown. This is non-linear and the rate likely slows as activity levels increase. Most of these studies are epidemiological, relying on recalled or self-reported data from participants, which can impact the accuracy of the information (like with nutritional studies).
- One particularly well-known critique of the relationship between exercise and longevity is the J-Curve. James O’Keefe discussed this in a previous podcast with Peter. This concept outlines the potential dangers of “too much” fitness in regards to longevity and health. There were 9 studies in O’Keefe’s review. Peter discusses the differences across the studies, pointing out some important issues that may decrease the potency of the conclusions. One glaring issue with the 9 studies mentioned is that 8 of the 9 had confidence intervals. However, 7 of the 8 studies with confidence intervals showed that the results from the J-curve data were not statistically significant. This means that while the data points may show a J-curve relationship between exercise and longevity (some increasing benefit from sedentary to fit, then a steep decreasing benefit from fit to most fit), the actual confidence in the results did not show that the data was significant. The biggest takeaway here is that, while on the surface these studies look to have significance, by looking deeper into the way the studies were conducted (sample sizes and confidence intervals), we see that the data is not statistically significant.
- While the J-curve may not be statistically significant, there are still risks that can occur with exercise. It is important to keep in mind that the incidence of risk is significantly lower than the benefits of exercise. The two major concerns in exercise are cardiac events and orthopedic injuries. The longer and more physically demanding something is, the higher the risk of sudden cardiac death; however, the risk is still very low ( 0.1-0.2%). This risk has less to do with the exercise itself and more with the need for better or more consistent health screenings, as many of the cardiac deaths associated with exercise were attributed to arrhythmias or atherosclerotic events. The other concern with exercise is orthopedic (overuse musculoskeletal injuries), which are involved in more complex, explosive movements; however, the risk is also small relative to the benefit.
- Extreme exercise may predispose individuals to atrial fibrillation and other cardiac events (like coronary calcification or fibrosis of myocardial tissue). This predisposition to A-fib may be attributed to genetics, in Dr. Attia’s experience. It is thought that athletes can develop A-fib because of the increased short-term inflammation, increased vagal tone at rest and heightened sympathetic tone during exercise. Because exercise at that caliber remodels the atria and ventricles to be larger and allow more blood to pump with each heartbeat, it is thought that this can potentially lead to A-fib in some athletes. The big takeaway here is that most people probably don’t need to be doing 20+ hours of intense cardio weekly and thus can decrease the risk.
- The majority of people can and should be exercising more, rather than less, and will see benefits from exercising for 1 hour per day. The risks of exercise (cardiac and orthopedic) are minimal, occurring in only 0.1-0.2% of the population who are even doing the amount of training that would bring on these events.
How: It is important to consider the potential risks of exercise recommendations. Additionally, we should understand the interpretation of studies surrounding these risks in order to fully identify whether or not the risk is greater than the benefit. Based on this podcast, the risk is virtually nonexistent for most and there is benefit from more activity rather than less. It is important to note that individual risk and situations should be considered, including lifestyle and current health status. These considerations help identify the optimal exercises and exercise structure that would benefit the individual.
Who: Andrew Huberman Ph.D., Professor of Neurobiology and Ophthalmology at Stanford School of Medicine
What: Sleep Toolkit: Tools for Optimizing Sleep & Sleep-Wake Timing
1. Sleep is the foundation of mental and physical health. It is essential for all types of performance. Sleep contributes to wound healing, skin health, longevity, cognitive health and all foundational bodily functions. In order for your brain and body to sleep and to focus, the nervous system needs cues or inputs. These are provided by different stimuli from the outside world. The stimuli that control sleep are light, temperature, food, exercise, body temp, and other substances, like caffeine. There are three critical periods in a 24-hour circadian cycle: 1. early morning/waking and the ~3 hours following waking 2. Daytime into early evening 3. 6-7pm until falling asleep. Using various stimuli during these critical periods can help support healthy sleep.
2. Critical Period 1: Ensure a healthy release of cortisol to increase metabolism, focus, movement, and the immune system, by viewing bright, natural outdoor sunlight within 30-60 minutes after waking for 5-30 minutes (depending on cloudiness). If you live somewhere that is commonly dark and overcast, sunlight replacement is suggested. Utilize things like ring lights, LED tablets, or sunlight panels. You can use temperature as a tool to increase core body temperature through cold water exposure (shower or cold tub) for 1-3 minutes or with exercise. The best time to exercise for the purpose of improved sleep is early in the day. Caffeine blocks adenosine receptors in the brain and helps limit sleepiness. Caffeine intake should be delayed for 90-120 minutes after waking when possible to avoid the afternoon crash. Eating healthy, whole foods early in the day supports energy levels throughout the day by increasing the metabolism.
3. Critical period 2: For the best sleep, avoid consuming caffeine during this time (not later than 4 pm and <100 mg total). If you like naps, try to limit them to 90 minutes or less and not so late in the day that it impairs your ability to fall and stay asleep at night. If you don’t like naps, try the Reveri app or a NSDR (non-sleep deep rest) script for 10-30 minutes during the day. Exercise in the afternoon will further increase your body temperature and delay your circadian clock. Caffeinated pre-workout is not recommended during this time. Getting natural light throughout the day and viewing sunlight in the late afternoon/sunset for 5-30 minutes serves an additional beneficial purpose by inoculating your system against the effects of artificial light in the late evening hours. When the sun is at a low solar angle, it triggers the neurons in your eye and communicates with your circadian clock that it is evening time and sleep is coming.
4. Critical period 3: Avoid bright artificial lights of any color. Even with blue blockers very bright light will wake up your brain and body. As the sun goes down, keep lights dim and physically low (desk and floor lamps instead of overhead lights), and use as little artificial light as possible. Use temperature in the evening by taking a hot bath or sauna for 20-30 minutes to activate the compensatory system to reduce your core body temperature. Make your sleeping environment cooler by at least 3 degrees to help stay asleep. If you have to exercise late in the day, follow with a hot bath or shower to adjust body temperature. Other tools: Eye masks can improve sleep (if not too tight or covering the forehead making you too warm), ear plugs may help (more personal preference), or elevating the feet by 3-5 degrees allow the circulation of fluids in your brain (lymphatic washout). For those with sleep apnea, there may be relief by training nose breathing during sleep by using medical tape to tape your mouth shut.
5. Other sleep tools: Consistent sleep and wake times improve quality and depth of sleep. Alcohol causes disrupted sleep, so avoid before bed. THC and CBD have an anxiety lowering effect, but don't optimize sleep. Huberman uses a combination of supplements, the “Sleep Stack”: magnesium threonate, apigenin, and theanine. You don't need to take all three, though they can have a synergistic effect. Suggested doses: 145mg Mg threonate (may need more or less), 50mg apigenin, and 100-400mg theanine. 5% of people report GI upset with Mg threonate. Theanine, even at the lowest doses, can cause vivid dreams that some find disruptive to sleep. Take supplements 30-60 minutes before bedtime. These are preferable to melatonin, which is a hormone. Taking melatonin chronically can potentially be problematic over time. May also try 2g glycine and 100mg GABA intermittently, every 3-4 nights to enhance sleep. Then, every other night, take 900mg Myo-Inositol in addition to the sleep stack on nights when not taking the glycine and GABA. Supplements suggested if environmental and lifestyle factors are not helping sleep.
How: Maximize sunlight viewing throughout the day. Exercise in the morning. Drink caffeine 90-120 minutes after waking and not past 4pm. Eat healthy food in the early morning hours. Take a cool shower in the morning and a hot bath or sauna in the evening. Avoid artificial or bright lights after sunset. Create a cool sleep environment. Try other tools as needed. These will all contribute to enhanced sleep and, therefore, daytime alertness and overall well-being.
Who: Tara Brach
What: Three Blessings in Spiritual Life: Part 2 Inner Fire
- Buddha says, “Inner fire is on the tip of intention.” Waking up the inner fire is becoming conscious of what really matters. Ask yourself, “What do I love?”
- When we are connected with inner fire, there is connectedness to all parts of life. Remember what matters and carry it through. The more you are in touch with what really matters, the more aligned you are. When you are connected with inner fire you are able to overcome all circumstances.
- “Whatever you frequently think about or ponder becomes the inclination of the mind.”- Buddah
- What keeps us from our inner fire?
- We want something deeper, but our energy is low so we opt for something more convenient.
- We seek the approval of others.
- When we pause on what is important, we achieve more.
How: Inner fire carries us forward. It’s important to bring intention, meaning, and care to our inner fire by allowing time to pause throughout the day. Build in short moments of pause to bring awareness and gratitude to your inner fire. Simply pause and ask, “What do I love?”