The last newsletter had a glitch which is to say I screwed it up! I mistakenly included a writeup from a previous medical mailbag instead of the correct writeup for the MMB segment on tendon injuries. That writeup along with the writeup for sleep aids, the MMB segment from episode 176 are both contained in this newsletter. The references for tendon injuries were correctly included in the last newsletter and are not reproduced here.

Table of Contents

• Tendon injuries-Episode 175 MMB

• Stuart Jenkins-Olympic Trials runner to co-founder …

• Episode takeaways:

  • References used for the MMB

Tendon injuries-Episode 175 MMB

Wrongly misconstrued and misclassified as tendinitis, the vast majority of tendon injuries are actually a result of a degenerative process and not an inflammatory one as the name ‘tendinitis’ would suggest. This is what we discovered during our medical mailbag segment when we answered a listener question related to tendon injuries; why they are so prevalent and why they are so hard to rehabilitate. While the dogma for many has been to utilize the tools that we often utilize against inflammation-ice, anti-inflammatory medications and even steroids, these have no impact on hastening the recovery from tendinosis and may even make things worse. Tendinosis is the degenerative process that results from overuse and injury and can be long lasting and very difficult to overcome. We talked about the ways to differentiate these two processes, how to employ best practices to overcome injury when you are faced with one and give some idea of how long you can expect the whole thing to take.

I have talked about the importance of sleep and its impact on exercise performance before but we have never talked specifically about how some of the different sleep aids on offer can work to help improve the quantity and quality of sleep that you get. There are a host of these things marketed to us; from weighted or cooling blankets to fancy pillows and mattresses to supplements like melatonin all offer the kind of sleep that we used to be able to get when we were teens. But is any of the hype true? Juliet and I spent the Medical Mailbag segment of this episode looking at the science behind the matter and hopefully it won’t lead to your drifting off…or maybe if it does, we will have discovered a new sleep aid! At any rate, you might be happy to know that there are some things that can help and surprised to learn that some of the things we thought were helpful are in fact, not quite and beneficial or at least not in the way we might hope.

Stuart Jenkins-Olympic Trials runner to co-founder of Blumaka

Stuart according to Stuart: CEO, accomplished leader, with a proven track record for innovation and success. Over 30 years of experience bringing industry changing ideas to market and shaping the future of footwear.

In a world where our running shoes are often treated like disposable fashion items, Stuart Jenkins, CEO of Blumaka, is on a mission to change the narrative. With a background in competitive running that once led him to the Olympic trials, he’s now tackling the issue of foam waste in footwear with a sense of urgency that’s downright inspiring. After uncovering the shocking amount of foam waste generated by shoe manufacturing – enough to produce billions of insoles – he decided to repurpose that foam into high-quality, sustainable products. This episode isn't just a feel-good story; it's a wake-up call about our consumption patterns. Jenkins shares his journey from an aspiring Olympian to an entrepreneur who’s not just talking about sustainability but actively making strides to improve it. He discusses the innovative processes Blumaka employs to ensure that the foam waste is transformed into products that not only last longer but also perform better than the standard insoles we’re used to tossing aside after a few runs. The irony? The very material we think of as trash is becoming a crucial component in high-performance footwear. And if you’ve ever wondered what happens to those old shoes piling up in your closet, Jenkins has some insight that might just inspire you to rethink your recycling efforts.

Episode takeaways:

• Shoes have a massive environmental footprint; consider where your foam footwear ends up after you've worn it out.

• When it comes to sleep, cooling blankets might actually help you catch those elusive Z's, according to some studies.

• If you're looking to get the most out of your sleep, investing in a firmer mattress could significantly enhance your rest and recovery.

• Don't underestimate the power of a sleep routine; it can make or break your performance on race day.

References used for the MMB

Moyen, N. E., Ediger, T. R., Taylor, K. M., Hancock, E. G., Holden, L. D., Tracy, E. E., Kay, P. H., Irick, C. R., Kotzen, K. J., & He, D. D. (2024). Sleeping for One Week on a Temperature-Controlled Mattress Cover Improves Sleep and Cardiovascular Recovery. Bioengineering (Basel, Switzerland), 11(4), 352. https://doi.org/10.3390/bioengineering11040352

• Sleeping on an active temperature-controlled mattress significantly improved sleep quality for participants (n=54). Cooled conditions led to:

  • increased time in deep and REM sleep.

  • improved cardiovascular metrics (decreased HR, increased HRV)

• Some sex differences reported (men showed increased light sleep time given warmer mattress conditions in the second half of the night).

Wei, Y., Zhu, Y., Zhou, Y., Yu, X., Lin, H., Ruan, L., Lei, H., & Luo, Y. (2023). Investigating the influence of an adjustable zoned air mattress on sleep: a multinight polysomnography study. Frontiers in neuroscience, 17, 1160805. https://doi.org/10.3389/fnins.2023.1160805

• A smart adjustable air mattress, which the authors say is designed for comfort, improved sleep efficiency with notable sex differences.

• All participants showed increased REM sleep, decreased N2 proportion, and reduced heart rate. Men showed a decreased N3 proportion. 

Kuo, T. B., Li, J. Y., Lai, C. T., Huang, Y. C., Hsu, Y. C., & Yang, C. C. (2013). The effect of bedding system selected by manual muscle testing on sleep-related cardiovascular functions. BioMed research international, 2013, 937986. https://doi.org/10.1155/2013/937986

• Firmness of mattress/pillow had an effect on cardiovascular function during sleep.

• The "strong" bedding system (firmer matress/pillow) reduced sympathetic activity, increased vagal tone, and improved baroreceptor sensitivity compared to the "weak" system (n=10).

Tobeiha, M., Jafari, A., Fadaei, S., Mirazimi, S. M. A., Dashti, F., Amiri, A., Khan, H., Asemi, Z., Reiter, R. J., Hamblin, M. R., & Mirzaei, H. (2022). Evidence for the Benefits of Melatonin in Cardiovascular Disease. Frontiers in cardiovascular medicine, 9, 888319. https://doi.org/10.3389/fcvm.2022.888319

• Review paper: Melatonin acts on the cardiovascular system through receptor-dependent signaling (via MT1, MT2, RZR, RORα receptors) and as a “free radical scavenger,” influencing multiple pathways that help reduce cardiovascular disease risk.

• Melatonin is being used in preclinical and clinical trials as a treatment/protective agent for cardiovascular diseases - clinical data is currently not definitive.

• Melatonin may protect the heart from damage, help control blood pressure, and reduce arrhythmias. 

Celorrio San Miguel, A. M., Roche, E., Herranz-López, M., Celorrio San Miguel, M., Mielgo-Ayuso, J., & Fernández-Lázaro, D. (2024). Impact of Melatonin Supplementation on Sports Performance and Circulating Biomarkers in Highly Trained Athletes: A Systematic Review of Randomized Controlled Trials. Nutrients, 16(7), 1011. https://doi.org/10.3390/nu16071011

Meta-analysis of 21 final articles found that melatonin supplementation: (varying doses across studies 5mg-100mg though most in the 5-10 range)

• reduced exercise-induced oxidative stress, reduces inflammation, lowers muscle damage biomarkers, improves liver and kidney function markers after intense exercise.

• did not significantly alter hormone levels (e.g. testosterone, cortisol, or growth hormone)

• improved metabolic parameters, improved some performance metrics (aerobic/anaerobic capacity, strength, fatigue)

• some evidence for decreased strength and power (see football study below)
  
  

Kisiolek, J. N., Smith, K. A., Baur, D. A., Willingham, B. D., Morrissey, M. C., Leyh, S. M., Saracino, P. G., Mah, C. D., & Ormsbee, M. J. (2022). Sleep Duration Correlates With Performance in Ultra-Endurance Triathlon. International journal of sports physiology and performance, 17(2), 226–233. https://doi.org/10.1123/ijspp.2021-0111

• Sleep duration decreased significantly over the course of a 3-day ultra-endurance triathlon, with total sleep time dropping from an average of 414 minutes pre-race to 300 minutes before stage 3.

• Less total sleep time was significantly correlated with slower race performance, particularly in stages 1 and 3, where TST explained about ⅓ of the variation in performance.

• Other sleep quality measures (sleep onset latency, wake episodes, and sleep efficiency) did not significantly change during the race.

de Sousa Nogueira Freitas, L., da Silva, F. R., Andrade, H. A., Guerreiro, R. C., Paulo, F. V., de Mello, M. T., & Silva, A. (2020). Sleep debt induces skeletal muscle injuries in athletes: A promising hypothesis. Medical hypotheses, 142, 109836. https://doi.org/10.1016/j.mehy.2020.109836

• Sleep is vital for athletes’ physical and cognitive recovery, but intense training can lead to sleep issues.

• Sleep debt is linked to a higher risk of musculoskeletal injuries, possibly due to hormonal imbalances (e.g., lower testosterone, higher cortisol).

• Poor sleep may trigger overtraining syndrome, inflammation, and immune dysfunction, which are all likely involved in the mechanism of injury.

Almendros-Ruiz, A., Lopez-Moro, A., Conde-Pipò, J., Santalla, A., Requena, B., & Mariscal-Arcas, M. (2023). The Effects of Melatonin Supplementation on Professional Football Player Performance: A Systematic Review. Nutrients, 15(20), 4467. https://doi.org/10.3390/nu15204467

• Systematic review (8 papers included in final analysis) on melatonin administration and football performance. 

• Inconsistent results: melatonin does not seem to directly enhance performance and may even decrease performance when taken before exercise.

• Melatonin shows promise in aiding recovery by reducing oxidative stress, muscle damage, and inflammation post-exercise (recovery vs. performance enhancement).
  
  

Dattilo, M., Antunes, H. K., Medeiros, A., Mônico Neto, M., Souza, H. S., Tufik, S., & de Mello, M. T. (2011). Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis. Medical hypotheses, 77(2), 220–222. https://doi.org/10.1016/j.mehy.2011.04.017

• Sleep deprivation leads to hormonal changes that promote a proteolytic environment

  • Increased cortisol 

  • Decreased testosterone

  • Decreased Insulin-like Growth Factor 1 (IGF-1)

• Authors hypothesize that sleep debt impairs muscle recovery by reducing protein synthesis and increasing protein degradation

Milewski, M. D., Skaggs, D. L., Bishop, G. A., Pace, J. L., Ibrahim, D. A., Wren, T. A., & Barzdukas, A. (2014). Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. Journal of pediatric orthopedics, 34(2), 129–133. https://doi.org/10.1097/BPO.0000000000000151

• Survey data shows sleep is correlated with injury in adolescent athletes - those with less than 8 hours of sleep were 1.7 times more likely to be injured.

Leeder, J., Glaister, M., Pizzoferro, K., Dawson, J., & Pedlar, C. (2012). Sleep duration and quality in elite athletes measured using wristwatch actigraphy. Journal of sports sciences, 30(6), 541–545. https://doi.org/10.1080/02640414.2012.660188

• The study assessed sleep via wristwatch actigraphy between Olympic athletes (n = 47) and controls (n = 20).

• Athletes had a significantly decreased sleep quality than controls, and a non-significant difference in time asleep that trended towards athletes sleeping for less time. 

• Sex differences were present: women slept for less time than men did, and had lower “sleep efficiency.” 

Charest J, Grandner MA. Sleep and Athletic Performance: Impacts on Physical Performance, Mental Performance, Injury Risk and Recovery, and Mental Health. Sleep Med Clin. 2020 Mar;15(1):41-57. doi: 10.1016/j.jsmc.2019.11.005. PMID: 32005349; PMCID: PMC9960533.

• Review of literature here documents a consistent-across-the-literature report of decreased time asleep and decreased sleep quality in athletes, with around 39% of athletes not receiving enough sleep (>7 hours).

• Review of issues that result from not enough sleep: worsened performance, increased injury risk, worsened mental health and cognitive performance.

• Review of team-level interventions: teams ought to promote a healthy sleep culture, screen athletes for sleep issues, treat sleep disorders, and manage training/travel schedules to prioritize sleep.

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