Each week, I comb through the latest endurance, sports science, psychology, and coaching research. So you don’t have to. Don’t worry, this is a nerdy passion. I try to distill it into plain language, practical takeaways, and reflections on what it means for the kind of running I do here at Waybound: thoughtful, purposeful, human. No hype, no clickbait. Just notes, honest questions, and my usual healthy dose of criticism and skepticism. Perfect for trail runners and overthinkers.
This week’s research roundup August 4 – Aug 11, 2025
I dive into fresh endurance and coaching research ranging from consensus on elite training and nutrition, to real-time biometric monitoring in desert ultras, hypoxic training effects, uphill/downhill biomechanics, and even a Foucauldian take on coaching discourse. We also get practical insights on postpartum pelvic floor health, patchy pre-race medical screening practices, clotting risks after ultras, foam roller training benefits, strength training’s impact on the gut microbiome, and how a simple run-walk plan can ease chronic low back pain. The common thread? Resilience, individual context, and the limits of reductionist or mechanical models, reminding us that running is as much about adaptation, intuition, care as it is about metrics or protocols.
This week’s research titles
– Consensus Statements—Optimizing Performance of the Elite Athlete
– Real‐Time Monitoring of Biometric Responses During a 200‐km Ultra‐Endurance Race Across the Desert
– Effects of 4-week continuous hypoxic training on skeletal muscle oxygenation using near-infrared spectroscopy and functional magnetic resonance imaging
– Biomechanical Considerations for Uphill and Downhill Trail Running
– Endurance running coaching’s mechanical topography: a Foucauldian discourse analysis of coaches’ knowledges
–The effects of lumbo-pelvic-hip complex strengthening exercises on pelvic floor health in postpartum women: A systematic review & meta-analysis
– Pre-race medical screening and harm reduction approaches in ultra-endurance racing: A descriptive pilot study of global practice
– Superior effects of high-intensity interval eccentric cycling training on neuromuscular adaptations with similar aerobic adaptations to concentric cycling
– Effects of acute sleep deprivation and extreme fatigue on cognitive performance and cardiac autonomic function during an expedition adventure race: a case report
– Promise and Pitfalls of Viscoelastic Testing for Assessing Blood Haemostasis in Ultra-Endurance Sports
– Resistance Training Reshapes the Gut Microbiome for Better Health
– The Effect of Exercises Accompanied by Foam Rollers on Some Body Composition Components and Health-Related Fitness Indicators in Women Aged 30–35 Years
See also 6 other worthy footnotes and essays of trail and ultra related science.
Consensus Statements—Optimizing Performance of the Elite Athlete
This consensus, developed at an international conference in November 2024, synthesizes current best evidence on training, nutrition, female athlete health, injury management, and emerging technologies for elite performance. It emphasizes sport-specific, individualized strategies; a mix of high-volume moderate work and high-intensity intervals; concurrent training; and resilience-building. Nutrition guidance stresses energy and macronutrient periodization, avoiding problematic low energy availability, and a cautious, evidence-based approach to supplements. For female athletes, the panel calls for validated hormone monitoring, attention to iron deficiency, and individualized symptom management, noting huge research gaps. Injury prevention remains challenging, especially for tendon injuries and Achilles ruptures, with rehabilitation guided by criteria-based progression. Tech innovations like wearables and multi-omics show promise but require validation.
Practical takeaways:
– Mix high-volume moderate training with supra-race pace intervals to boost VO₂max, economy, and durability.
– Target the ability to maintain performance late in long events through specific training and nutrition.
– Add resistance, plyometric, sprint training regularly; concurrent work doesn’t blunt adaptations.
– Periodize energy, carbs, fluids to match training phase and competition needs; avoid chronic low energy availability.
– Only use evidence-based aids (e.g., creatine, caffeine) after risk–benefit review and deficiency testing.
– Track cycles with validated methods, monitor iron annually, individualize adjustments for symptoms or contraception effects.
– Act early on tendon issues, rehab Achilles ruptures cautiously, and use shared decision-making for return-to-sport.
-Wearables, biomarkers, AI may allow personalization, but remain experimental for elite sport.
This is basically the “ultra-elite edition” of what I already preach: train with intention, fuel with precision, adapt to unique physiology and individual variability, see the athlete in context (life, health, environment), and balance ambition with durability. The heavy emphasis on resilience, multidisciplinary care, and trial-and-error nutrition mirrors our trail/ultra reality.
– Use the durability framework for long ultra prep, especially multi-day events.
– Integrate concurrent training blocks for trail-specific power and downhill resilience.
– Be proactive on female athlete health markers and use iron profiling.
– Keep rehab criteria-based, not date-based, for returning athletes post-injury.
The female athlete sections are overdue but still limited by evidence gaps.
Real‐Time Monitoring of Biometric Responses During a 200‐km Ultra‐Endurance Race Across the Desert
This observational study tested a prototype real‐time biometric monitoring system during SAMLA 2023, a 200‐km desert ultra‐endurance race in Qatar involving swim, run, bike, and kayak stages. Eighteen male Qatari athletes wore GPS units, ingestible core temperature pills, skin temperature sensors, and HR monitors. Data were sent via smartphone to a cloud dashboard in real time. The system captured ~660 hours of GPS data (up to 57 continuous hours for one athlete) but only ~42% of potential physiological data due to sensor disconnection, loss, or excretion of the pill.
Core temps ranged from hypothermic (35.7°C) to hyperthermic (39.2°C), with similar averages between day and night despite a 12°C ambient swing (16–28°C). One athlete collapsed and was hospitalized, but their biometric readings gave no early warning, underscoring the limits of single‐variable monitoring. Even in “moderate” desert conditions and low race intensity, ultra‐endurance athletes can hit risky thermal extremes (>39°C or <36°C). “Safe” temperatures can still cause dangerous thermal stress. While the sample is small and tech still clunky, it’s a big step toward integrating real‐time biometrics into ultra safety protocols, and it challenges assumptions about when and where thermal risk shows up.
Effects of 4-week continuous hypoxic training on skeletal muscle oxygenation using near-infrared spectroscopy and functional magnetic resonance imaging
This neat little study compared 4 weeks of continuous hypoxic treadmill training (simulated 2,500 m altitude) with normoxic training in 26 healthy young men. Both groups trained 3x weekly at their gas exchange threshold. Muscle oxygen saturation (SmO₂) was tracked during graded exercise, and calf muscle perfusion was assessed during an ischemia–reperfusion test. The hypoxic group showed significantly higher SmO₂ at all measured exercise intensities post-training and improved BOLD-derived measures (peak hyperemic value, minimum ischemic value, time-to-peak, time-to-recovery), indicating enhanced vascular reactivity and oxygen utilization efficiency. Over half of the hypoxic group met the “responder” threshold for SmO₂ improvements, and over 90% did so for BOLD measures.
This study didn’t measure real-world performance changes, so translation to race outcomes is still speculative. The sample was small, male-only, and the protocol short. Without performance metrics, we can’t confirm whether these microvascular changes matter for running times.
Practical takeaways:
– Hypoxic training improved muscle oxygenation at multiple intensities, suggesting better oxygen delivery/utilization during endurance efforts.
– Faster oxygen delivery and clearance post-occlusion points to improved microvascular reactivity, possibly aiding recovery between surges in trail or ultra races.
– Adaptations seem muscle-local, not just systemic, so benefits could apply even if VO₂max changes are minimal.
– A 4-week, thrice-weekly protocol in a hypoxic chamber was enough to produce measurable microvascular gains.
In other words: short targeted hypoxic exposure may meaningfully influence oxygen handling in the legs without requiring prolonged altitude camps (esp. if they’ve plateaued in normoxic training). For athletes constrained by location, a simulated hypoxic block could be an interesting stimulus layered into an annual plan. Given individual variability, hypoxic training should be tested cautiously before race-critical periods. That said, the focus should remain on sustainable load, recovery, and how an athlete responds: hypoxia is a “bonus spice,” not the main course.
Biomechanical Considerations for Uphill and Downhill Trail Running
This dissertation dissects how uphill and downhill running place unique mechanical demands on the body, focusing on stride patterns, joint loading, muscle recruitment, and energy costs. Uphill running tends to shorten stride length, increase cadence, and shift muscular emphasis toward the hip extensors and plantar flexors, while downhill running lengthens strides, increases braking forces, and relies heavily on eccentric quadriceps work. The paper also examines ground reaction forces, posture, and energy expenditure in varied gradients. Importantly, it highlights how trail conditions (technical vs. smooth) further modify mechanics, and how runners might adapt their technique to reduce injury risk and improve efficiency.
Practical takeaways:
– Uphill: Shorter, quicker steps and a forward lean from the ankles improve economy; strong glutes, calves, hip flexors are key.
– Downhill: Controlled cadence, slight knee flexion, stable trunk reduce impact forces; quad eccentric strength is non-negotiable.
– Incorporate both eccentric (downhill: step-downs, weighted lunges, downhill strides) and concentric (uphill: hiking intervals, uphill sprints) strength work to avoid asymmetrical fatigue patterns in ultras. Athletes should regularly practice both on race-like terrain, especially under mild fatigue, to ingrain efficient mechanics and avoid the “quad death” many suffer late in ultras.
– Foot placement precision and ankle stability drills pay dividends; unstable terrain magnifies mechanical inefficiencies.
– Technique changes take time to ingrain; abrupt alterations (e.g., forced cadence) may increase injury risk.
Uphill and downhill efficiency isn’t just about strength, but about awareness, adaptability, and respect for the body’s limits. A runner who can subtly shift technique to match the gradient, while staying relaxed and confident, will not only be faster but more resilient over long races. The paper reaffirms that “strength” in trail running is multidimensional; a marriage of endurance, proprioception, and pacing wisdom.
Endurance running coaching’s mechanical topography: a Foucauldian discourse analysis of coaches’ knowledges
I let out a long sigh every time I see or Foucault, so I could not not include this study. This one takes Michel Foucault’s discourse analysis methods and applies them to six of the most popular endurance running coaching textbooks. The authors show that across physiology, biomechanics, psychology, nutrition, and training methods, the runner’s body is consistently articulated as a machine to be built, tweaked, and controlled. By mapping recurring terms, statements, and concepts, they reveal a mechanical “episteme” that shapes not just how training is planned, but also which kinds of knowledge are considered legitimate. Even seemingly human-centered approaches, they argue, are absorbed into this machine logic, reproducing control, prescription, and output-maximization while marginalizing relational, environmental, and intuitive dimensions of running. The paper challenges whether true innovation in coaching is possible without first breaking free from these entrenched body-as-machine relations.
Practical takeaways:
– Coaches’ language and practices overwhelmingly frame athletes as mechanical systems; this limits space for relational, adaptive, and athlete-led approaches.
– Adding more “sciences” (nutrition, biomechanics, psychology) often just adds more mechanical inputs, rather than genuinely broadening the coaching lens.
– Controlled development is not the same as athlete-led development; constant monitoring and prescription can stifle adaptability and self-awareness.
– Human-centred initiatives (e.g., athlete-centred coaching) risk being co-opted by the machine model unless the underlying discourse changes.
– Breaking the machine logic might involve creating training spaces that value subjective experience, embodied decision-making, and environmental context as much as metrics.
– If introducing a “new” coaching method, examine if it’s truly changing the underlying relationship with the athlete, or just feeding more data into the same machine logic.
Coaching should nurture adaptable, self-aware runners rather than optimise “machines.” Without changing the language and assumptions we bring to coaching, even progressive tools get bent back toward control and output obsession. For trail/ultra coaching, it’s a call to place terrain feel, environmental responsiveness, and athlete intuition at the core, not just as “soft add-ons” to a physiological program.
The study’s strength lies in applying Foucault’s rigorous, theory-driven discourse analysis to a domain that usually takes its knowledge for granted. It’s interesting and rare to see coaching literature interrogated this deeply. However, the focus on textbooks might miss how coaching actually plays out in real interactions; athletes often experience far more nuance, care, and flexibility than manuals suggest. The “body-as-machine” critique is convincing, though perhaps overly totalizing; in practice, some coaches blend mechanical and relational approaches fluidly. Still, the argument is valuable in showing how easy it is for even good intentions to be subsumed by dominant metaphors.
One striking point the authors make is how “helicopter coaching” has become normalized, mirroring overprotective parenting, in which coaches, aided by modern tech, hover over every movement and micro-adjustment. This creates environments where runners are rarely allowed to experiment or self-direct, because deviation is seen as inefficiency rather than growth. The paper also points out that even innovations designed to be athlete-centered (like growth mindset programs or ecological dynamics) often end up bent back into machine-compatible forms (measured, controlled, and standardized) because the underlying soil (mechanical episteme) hasn’t changed. The authors liken this to planting wildflowers in an industrial assembly line: they may sprout, but only in machine-shaped pots.
For coaching practice, this suggests we should consciously check our language, planning structures, and use of tech to avoid defaulting into a machine-maintenance role. It means making space in programs for athlete-driven decision-making, subjective feedback loops, and training that honors unpredictability. In ultra and trail contexts, that might mean fewer prescriptive intervals, more exploratory runs, and structured reflection on body-feel and environment.
On a personal note: Without going into his personal life, Foucault’s frameworks are powerful for uncovering structures of power and how knowledge is shaped by them (I’ve used it in my work often enough). They can also be frustratingly totalizing; implying that escape from dominant discourses is almost impossible. In coaching, this can risk overlooking the messy, improvisational reality where athletes and coaches regularly bend or subvert the “rules” of the system. His tendency to emphasize structures over agency can underplay how coaches and athletes actively co-create meaning. Moreover, Foucauldian analysis can be heavy on diagnosis and light on actionable solutions; useful for revealing the prison walls, but less clear on how to break out without replacing one control system with another. I’ll leave it at that.
The effects of lumbo-pelvic-hip complex strengthening exercises on pelvic floor health in postpartum women: A systematic review & meta-analysis
This systematic review and meta-analysis looked at whether strengthening the lumbo-pelvic-hip complex (LPHC), with or without additional isolated pelvic floor muscle training (PFMT), improves pelvic floor muscle (PFM) health in postpartum women. Eleven RCTs (503 women, ≤2 years postpartum) were included, covering interventions from 6–12 weeks long, with varied exercise types, dosages, and supervision levels. LPHC + PFMT improved PFM endurance (+5.51 seconds) and PFM strength (+0.43 on the Modified Oxford Scale), but effects on pelvic floor dysfunction (PFD) symptoms were not statistically significant. Evidence quality was low due to small samples, inconsistent outcome measures, and methodological variability.
Practical takeaways:
– LPHC work seems most effective when paired with targeted PFMT rather than replacing it.
– Exercises that activate PFMs, transverse abdominis, and diaphragm together may enhance lumbopelvic stability and continence.
– Hip stabilization and gluteal strength work are relevant, given shared fascial connections with PFMs.
– Many interventions underdosed; load progression is essential for strength and symptom improvements.
– Correct PFM activation is tricky; professional guidance boosts technique and engagement.
– Current studies are underpowered to detect meaningful changes in quality of life or incontinence scores.
In other words: postpartum rehab shouldn’t isolate one muscle group in a vacuum: athletes may benefit from whole-system LPHC training. The synergy between PFMs, hips, deep core parallels how trail strength work supports stability on techy terrain. However, like in ultrarunning, dosage, progression, and quality of execution are everything; a couple of bodyweight sets without progression likely won’t cut it.
In postpartum return-to-running programs, consider progressive, functional LPHC strengthening that integrates PFMT, hip stabilization, and deep core activation. Prioritize movement quality, progressive load, and sport-specific functional positions (standing, walking, running). Include education on PFM recruitment, and where possible, collaborate with pelvic health physios for assessment and feedback.
Pre-race medical screening and harm reduction approaches in ultra-endurance racing: A descriptive pilot study of global practice
This pilot study audited 200 ultra races in 67 countries (2023–2024) to assess how often and how well pre-race medical screening and harm-reduction measures are applied. Researchers reviewed 40 data points per race, incl. 22 screening and safety metrics available at registration. They found that a quarter of races had no medical screening at all, and most existing measures were minimal, inconsistent, and poorly aligned with international guidelines.
Three-quarters of races have some screening, but often only basic waivers or vague “medical conditions?” checkboxes. Only 29% required evidence of endurance experience, and <10% used targeted health questions. May enter extreme events with minimal vetting. Less than 13% of races provide hydration/nutrition guidance at registration, leaving runners to source this elsewhere. South America and high-altitude races (>2500 m) had more comprehensive screening. Most races don’t assess specific risks like heat stroke, altitude illness, or EAH at sign-up; athletes should self-screen and prepare. Higher altitude races tend to require acclimatization advice and physician sign-off, but still not universally. Liability was overwhelmingly transferred to participants through waivers rather than managed proactively.
The paper only looked at registration-stage safety measures, some events may do more later, but by then athletes are already committed. We can’t assume that event organizers will adequately screen for risks or prepare athletes for the conditions they’ll face. Our role, then, is to fill that gap, using targeted questioning and scenario planning to anticipate medical, environmental, and logistical challenges. It’s a reminder to train for the race’s true demands, not just its distance or profile, and to educate runners on hydration, heat/altitude acclimatization, and self-monitoring even if the race doesn’t: this could cover cardiovascular risk, injury history, thermal tolerance, hydration/nutrition planning, altitude strategy, and relevant experience.
Running Improves Mental Health Symptoms and Pain Catastrophising in Adults with Chronic Low Back Pain
A value any research done on mental health. This analysis tested whether a progressive run-walk program could improve mental health and pain-related thinking in 40 adults (18–45) with non-specific chronic low back pain. Participants ran 3× per week for 20–30 min., gradually increasing run intervals, while controls remained on a waitlist. Compared with controls, runners showed significant improvements in overall mental health, depression, stress, and pain catastrophizing (but not anxiety), suggesting different mechanisms may be at play. In just three months, a gentle run-walk plan chipped away at fear and gloom in people told for years to be cautious. The gains weren’t just in pace or pain, they were in mindset, in seeing running not as a threat but as a way back to agency. It’s a reminder that sometimes the shortest intervals run can open the longest doors.
Practical takeaways:
– Even modest-intensity, structured run-walk programs can meaningfully reduce pain catastrophizing in chronic low back pain.
– A gradual, interval-based approach starting with short bouts (15–45 sec run, 2 min walk) can be effective and well-tolerated.
– Improvements were achieved despite participants starting with relatively low baseline mental health symptoms, effects may be larger in those with higher distress.
– Nine study-related adverse events occurred. progression and load management matter.
Psychological gains may partly reflect regular contact and support from exercise physiologists, not running alone. The small sample and exclusion of recent runners limit generalizability, and baseline distress was low, capping the potential effect size. The waitlist control did not match contact frequency, so placebo and relational effects may inflate results. Coaches should emphasize early positive experiences, monitor for lower limb overload, and weave in supportive communication. While benefits may be smaller for those without baseline distress, framing sessions as tools for confidence and autonomy could still pay dividends.
The effect of exercises accompanied by foam rollers on some body composition components and health-related fitness indicators in women aged 30-35 years
This study tested an 8-week Pilates-inspired training program using foam rollers on women aged 30–35 (n=8). Sessions ran 3x/week, with exercises combining rolling, balance, resistance, and functional movement. Pre- and post-tests measured strength, flexibility, coordination, balance, and body composition. Results showed significant improvements: increased muscle mass, protein, water, and minerals; decreased fat mass; and better grip strength, flexibility, balance, and coordination. The authors conclude that foam roller–based training is not just recovery fluff, but a tool that can actually improve body composition and functional health indicators.
Practical takeaways:
– Foam roller sessions may help reduce fat mass and increase lean muscle.
– Improved flexibility and balance suggest that rollers add a neuromuscular challenge, not just a massage.
– Consistent foam rolling improved grip strength and arm endurance.
– Roller-based programs could be a low-cost, accessible training supplement for people with limited equipment.
This was a very small sample (8 women), no control group, so results should be read as “promising” rather than “proven.” Coaches might integrate roller-based exercises as a supplement for balance, coordination, and flexibility (esp. for athletes with limited gym access, this could add functional strength and recovery benefits in short, manageable sessions). Rollers are a “nice-to-have” adjunct, not a replacement for running-specific strength or conditioning.
Promise and Pitfalls of Viscoelastic Testing for Assessing Blood Haemostasis in Ultra-Endurance Sports
This invited commentary explains how ultras (heat, dehydration, muscle damage, inflammation) perturb the body’s clotting system. The athletes showed a transient “hypercoagulable” pattern post-race: intrinsic pathway activation, sturdier clots, and signs of throttled fibrinolysis, without clinical events. VET captured clot firmness and lysis resistance in real time, offering a more holistic window than plasma tests alone. The authors highlight big caveats: very small, elite sample, variable timing of blood draws, and no direct platelet-function testing—and call for larger, longitudinal studies to define normal post-ultra ranges and meaningful risk thresholds.
Practical takeaways
– Aggressive rehydration + post-race cooling likely help nudge haemostasis back toward baseline. Easy spins/walks after finishing can aid circulation.
– Delay the red-eye when you can: long-haul flights within 24h of an ultra may add a “second hit.” If possible, push travel, walk the aisle, and use calf pumps on board.
– Compression can be a low-risk helper: compression socks may be useful when standing around after finish lines or during travel.
– Masters & high-risk athletes should be extra intentional: double down on fluids, movement, and flight/post-race planning.
– Routine aspirin/anticoagulants aren’t recommended for healthy athletes; bleeding risk > presumed benefit. Talk to a clinician if you have real risk factors.
Lab “hypercoagulability” ≠ clinical clot. These changes look like an acute inflammatory state and usually resolve, don’t catastrophize a transient lab pattern. Bake recovery logistics into race planning: a 10-minute walk, 1–2L fluids with electrolytes in the first hours, a carb-forward meal, legs-up breaks, and compression during standing/queues. Prioritize a next-day travel window and set an hourly “move alarm” if you must fly. Treat sauna/hot tubs carefully right after hot races; prefer cool or temperate immersion and shade, then heat later in the week. Add “circulation snacks” to the plan: 5–10 minutes easy spin/walk the evening of and the morning after. No routine aspirin “just in case.” If you’ve had prior VTE or significant risk, that’s a medical pathway, not a coaching one.
Resistance Training Reshapes the Gut Microbiome for Better Health
This new preprint shows that resistance training can reshape the gut microbiome, but only if your body actually adapts. Researchers tracked 150 previously sedentary adults through 8 weeks of machine-based strength training. On average, gut diversity didn’t change much. But people who gained the most strength showed clear microbiome shifts: beneficial bacteria like Faecalibacterium and Roseburia hominis increased, both linked to anti-inflammatory, SCFA-producing pathways. The changes built gradually and were most obvious after 8 weeks, suggesting strength gains and microbial changes go hand in hand.
Practical takeaways
– Consistent strength work (2–3×/wk) may nudge your microbiome in a healthier direction, esp. if you actually get stronger (progressive overload, adequate recovery).
– The microbiome signal tracked strength gains, not just showing up. Program blocks you can “win” (e.g., 6–8 weeks with clear progress metrics).
– Since the study didn’t manipulate diet, pair lifting with fiber-rich, plant-diverse meals to support SCFA producers like Faecalibacterium and Roseburia.
– Expect slow burn, not fireworks: Changes were clearer by week 8—think in mesocycles, not weekends.
This was in sedentary adults using smart machines; effects in already-trained trail runners (who have different diets/loads) might be smaller or different. No non-exercise control, and metabolomics were null. Still, strength may also help cultivate a healthier gut ecosystem. But the benefits depend on progressive adaptation: you need to lift consistently (2–3×/wk), aim for measurable gains (reps or load), and support those changes with a diverse, fiber-rich diet. Don’t expect overnight results, think in blocks of 6–8 weeks. For trail and ultra athletes, this reinforces the value of mixing in steady strength cycles: you’re not only building durable muscles and joints, but potentially nudging your gut toward a more resilient state, which can matter for fueling and recovery on long days out.
Worthy footnotes
A Preliminary Study of Lipid Complex Supplementation on Fatty Acid Profile and Blood Antioxidant Status After Downhill Running in Athletes
Łakomy et al., Scientific Reports, 2025
Three weeks of low-dose green-lipped mussel lipid complex (PCSO-524®, ~58 mg EPA + 44 mg DHA/day) in ultramarathoners led to slightly better antioxidant responses (higher post-run SOD, lower MDA) and a healthier AA/EPA ratio after a 30-minute downhill run. It didn’t affect inflammatory cytokines (IL-6, TNF-α), likely because the dose was low and the workout wasn’t inflammatory enough.
For runners/coaches this means there are possible benefits: it may help limit oxidative stress and protect cell membranes during heavy downhill/eccentric training blocks. However, effects were modest, with no measurable impact on inflammation or performance. If you try it, pair with strong recovery habits; use higher omega-3 doses (≥500 mg/day EPA/DHA) for a better shot at benefits. Bottom line: Not worth routine use for most, but could be a niche tool for eccentric-heavy training phases.
Superior effects of high-intensity interval eccentric cycling training on neuromuscular adaptations with similar aerobic adaptations to concentric cycling
John DesRochers, Alexis Chow, David Rubin & Altamash Raja, Research in Sports Medicine, 2025
A cycling study yes, still interesting for runners. They compared 8 weeks of high-intensity interval eccentric cycling (EC) and concentric cycling (CC) in healthy men (n=17) to see how each affected aerobic capacity, muscle size, and muscle function. Both groups trained twice weekly with similar perceived effort, progressing in intensity and volume. Results showed that EC produced much greater gains in concentric sprint peak power output (+27% vs. +9%), squat jump height, and quadriceps cross-sectional area, while aerobic improvements (VO₂peak, incremental peak power output, 6-min walk distance) were similar between EC and CC. Fascicle length and pennation angle didn’t change significantly in either group.
Practical takeaways:
– EC HIIT can build strength/power and aerobic capacity in just two sessions/week.
– Expect bigger jumps in sprint power and explosive leg function from EC than CC.
– EC stimulates more hypertrophy in the quads than CC, useful for strength and injury resilience.
– Both EC and CC deliver similar VO₂peak and endurance gains; no aerobic disadvantage to going eccentric.
EC may require more coordination; results may vary depending on skill with eccentric pedaling. For trail and ultra athletes, this study suggests a way to add potent strength stimulus without sacrificing aerobic development. For runners, EC HIIT could replace some traditional hill sprints or plyo sessions, delivering both muscular and aerobic benefit with lower perceived joint strain. On-bike eccentric training in the gym or with specialized ergometers could be especially valuable in injury return-to-play or as an alternative high-power stimulus for athletes prone to overuse from running.
Resistance Training Reshapes the Gut Microbiome for Better Health
Straub D., Englert T., Beller A., et al. bioRxiv (preprint), 2025
This new preprint tested how 8 weeks of resistance training in 150 previously sedentary adults influenced the gut microbiome. Everyone trained 2–3 times a week on digitally monitored machines, with every rep and load tracked. Across the group, the microbiome looked pretty stable, and stool metabolomics didn’t shift much. But when researchers zoomed in on individual response, a clear pattern emerged: participants who gained the most strength (top ~20%) showed significant microbiome changes by week 8, especially enrichment of Faecalibacterium and Roseburia hominis—butyrate producers linked to gut health and reduced inflammation. In other words, the gut didn’t care if you just showed up; it changed most when your body actually adapted.
The study is valuable because it ties objective strength improvements—not just training exposure—to gut remodeling, filling a gap left by endurance-focused research. Still, the evidence is preliminary: no non-exercise control group, only 16S sequencing (not full metagenomics), and stool metabolomics came up null. For athletes, the message is practical: consistent, progressive strength gains may benefit not just muscles and joints but also the microbiome, with potential knock-on effects for recovery and long-run gut resilience. It’s not conclusive, but for trail and ultra runners already balancing strength work with mileage, this adds one more reason to treat progression in the gym as seriously as progression on the trails.
Effectiveness of Cold-Water Immersion vs. Massage in Reducing DOMS After a Murph-Style Workout
Pereira GS, Paulino GE, de Almeida THMF, et al. PLOS ONE, 2025
This study compared cold-water immersion (20 minutes at 8 °C) and massage (20 minutes Swedish style) after a brutal “Murph”-style workout. Eighteen trained CrossFitters took part. Cold-water immersion reduced soreness much more than massage, by 48 hours, none of the cold group reported pain at rest or while exercising, while the massage group still had some discomfort. Massage did show some benefit, particularly in raising pain tolerance over time, but it didn’t match the quick relief of cold water. For trail/ultra runners, this is a practical reminder: after quad-smashing descents or race weekends, a single cold plunge can make stairs and recovery runs feel possible again within 1–2 days. Massage may still be useful for relaxation and nervous-system downshifting, but if you need to bounce back fast, cold is the sharper tool. Just don’t overuse it during heavy training blocks, since frequent cold exposure can blunt some strength adaptations.
Effects of concurrent training on the Chinese female elite triathletes
Liu C, Zhang Z, Mao R, Xia L, Xie Y. PLOS ONE, 2025
This study looked at 12 elite Chinese female triathletes who did 8 weeks of structured concurrent training (3x/week strength + 3x/week endurance). The block led to stronger squats, better jump power, improved short-distance swim and run times (400 m swim, 2000 m run), and a ~3.6% faster sprint triathlon performance, without changes in VO₂max or longer race performance. The key: adding heavy, progressive lifting and explosive work improved short-distance racing ability without hurting endurance. For training, this suggests athletes can benefit from a focused 6–8 week strength block. Think heavy squats, jump squats, plyometrics, and hill sprints, while keeping endurance load steady. Expect gains in power, surges, and closing speed rather than all-day stamina. To hold onto progress, maintain at least one heavy session per week once the block is done.
Combining Time-Restricted Wheel Running and Feeding During the Light Phase Increases Running Intensity Under High-Fat Diet Conditions Without Altering the Total Amount of Daily Running
Shiba et al., International Journal of Molecular Sciences, 2025
This rat study found that when both exercise and eating were synced to the animals’ natural active phase, they gained less weight and fat on a high-fat diet, had healthier liver and muscle clock rhythms, and reaped more metabolic benefits than when those activities were done at the “wrong” time. Even though mismatched-timing rats ran harder in short bursts, they didn’t see the same fat-loss or clock-health gains, showing that intensity can’t fully offset circadian misalignment. For runners, this could mean much for how timing matters: try to place key workouts and fueling in your natural energy window (often late morning to afternoon) to support performance, recovery, long-term metabolic health, especially if diet quality isn’t perfect.
About Waybound 