Blonyx Research Update: What Hybrid Training Does to Your Body, the Boston Taper, and Protein's Big Catch

What HYROX and CrossFit Actually Do to Your Body

This review mapped 39 studies from 2015 to 2025 on what high-intensity functional training, the kind used in CrossFit and HYROX, actually does physiologically. Across the studies, VO2max improved by 8 to 15% and strength in major lifts improved by 10 to 20%, alongside gains in local muscular endurance and power output. These benefits were more pronounced in people who were already trained, particularly those with more resistance training experience, not people just starting out. More experienced athletes also showed better fatigue tolerance and more consistent performance under stress.

My thoughts: This is a nice data-backed answer to "does HYROX or CrossFit actually make you fitter, or just more tired." Yes, on both the aerobic and strength side, especially once you're already reasonably trained.

The Taper That Actually Predicted a Faster Boston Marathon

This study surveyed 917 runners registered for the 2022 Boston Marathon, 495 women and 422 men, about their training in the year before the race and matched it to their official finish times. Higher weekly running distance, more running sessions, more hard or quality sessions, and more cross-training in the four months before the race were all linked to faster times. The clearest finding was about pacing training itself: runners who cut back their running frequency in the final four months, relative to the prior eight, finished faster than those who kept the same frequency or increased it.

My thoughts: This is a great real-world confirmation of something we already coach: build the base, then actually back off frequency before race day. The runners who trusted the taper ran faster than the ones who kept grinding right up to Boston.

Why Protein Studies May Be Overselling the Benefits

This meta-analysis pooled 75 randomized trials and 1,206 athletes using a Bayesian statistical model to see whether protein supplements actually improve athletic performance and recovery, not just support muscle growth. Protein-carbohydrate combinations significantly improved endurance performance compared to placebo, and pure protein supplements also significantly improved both endurance performance and muscle strength. For recovery, pure protein outperformed carbohydrate alone for glycogen resynthesis. There's an important catch though: every one of these significant results came from trials where the protein group and control group weren't eating the same total calories, so some of the apparent benefit could simply reflect extra energy intake rather than protein itself. The authors call the overall evidence for protein's effect on performance and recovery limited because of this.

My thoughts: The interesting part here isn't that protein-carb combos help performance, it's that none of these positive findings survive once you account for total calories. Every significant result came from trials where the supplemented group simply ate more overall. That doesn't mean protein does nothing, but it means we can't credit protein alone for these numbers yet. Worth reinforcing that comparison studies need matched energy intake before overselling the results.

— That's all for now, train hard!