Each week in my Research Update, I distill the latest sports science research into practical insights to help you improve your training, performance, and recovery.
In this week's update:
- How caffeine can quietly reduce deep, restorative sleep
- What to eat to ensure an easier return from injury recovery
-
Whether vitamin D helps your muscles recover faster
Caffeine Impairs Sleep Quality and Duration
This review analyzed 32 studies using EEG to examine how caffeine affects sleep quality and duration. The studies used caffeine doses ranging from about 80 mg (roughly one cup of coffee) to more than 600 mg, delivered as coffee, energy drinks, capsules, and tablets. Across the studies, caffeine consistently reduced slow-wave sleep—the deepest and most restorative stage of sleep—while increasing lighter sleep stages. It also delayed sleep onset, reduced total sleep time, and lowered overall sleep efficiency. The effects were dose-specific and timing-dependent, but even caffeine consumed several hours before bed was shown to impair sleep quality.
My thoughts: I stopped drinking caffeine about 10 years ago and noticed it in my sleep more than anything else. I simply felt more rested most nights. I’m a firm believer that even though it's a great ergogenic aid, there are drawbacks that people rarely consider. Impact on sleep and therefore recovery is one of them. If you're sacrificing sleep to train harder, it’s worth reading up on how sleep affects your performance.
The Right Nutrition Can Speed Up Injury Recovery
This review examined how nutrition can help prevent and manage illness and injury in elite cyclists. During injury rehabilitation, energy needs often remain high despite reduced training, and under-eating can slow tissue repair and increase lean muscle loss from inactivity. The researchers emphasize that maintaining adequate protein intake, strategically adjusting carbohydrate intake, and ensuring sufficient intakes of nutrients such as vitamin D, calcium, iron, collagen, and omega-3 fats. The review also highlights the importance of preserving bone health and immune function during periods of reduced activity.
My thoughts: Great practical advice for anyone trying to bounce back from an injury. Most athletes instinctively eat less when they can’t train, but that’s often the wrong move. Your body is rebuilding tissue, managing inflammation, and trying to preserve muscle mass. Recovery is an active process, and good nutrition, and supplements like HMB Sport, can speed it up.
Vitamin D May Speed Up Muscle Growth and Repair
This study tested whether 12 weeks of vitamin D supplementation of 3,000 IU/day could enhance muscle protein synthesis in healthy young adults. During each visit, after supplementation, participants completed resistance exercise and consumed 22g of whey protein.
Vitamin D did not increase total muscle protein synthesis over the full four-hour recovery period. However, it did enhance the early anabolic response during the first hour after exercise and protein intake, suggesting that vitamin D may help muscles respond more quickly to training and nutrition.
My thoughts: This is one of the first studies to directly show that vitamin D may enhance the muscle-building response to protein after exercise. The effect was subtle, but potentially meaningful over time. If you live in a northern climate and don’t get much sun in the winter, it’s worth making sure your vitamin D intake is covered. Blonyx Multivit+ includes your daily vitamin D alongside 22 more essential vitamins and minerals to help fill those nutrient gaps when your diet falls short.
That’s all for this week.
If you learned something new and are curious to know more, check out more articles and my growing list of weekly Blonyx Research Updates where I help you further improve your athletic performance by keeping you up to date on the latest findings from the world of sports science.
— That's all for now, train hard!
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