Science
The research the BLOCKS assistant answers from: 1,118 studies and 81 guides, each graded for how strong the evidence is and who it was measured on, with a link to the original paper.
1,118 entries
BThe Response to Long-Term Overfeeding in Identical TwinsBouchard 1990BEnergy-balance studies reveal associations between gut microbes, caloric load, and nutrient absorption in humansJumpertz 2011B+Walnuts Consumed by Healthy Adults Provide Less Available Energy than Predicted by the Atwater FactorsBaer 2016B+Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human dietsNovotny 2012B+Carbohydrate ingestion during prolonged exercise and net skeletal muscle glycogen utilization: a meta-analysisRothschild 2026BGraded carbohydrate ingestion up to 120 g·h−1 attenuates the reduction in critical power following 3 h of moderate-intensity exercise in a dose-dependent mannerNorte 2026BAccelerating endogenous carbohydrate oxidation impairs durability of the moderate-to-heavy intensity transitionMaunder 2026BExperienced recreational runners who gradually transitioned to Vibram FiveFingers over 10 weeks showed more bone marrow oedema on foot MRI than runners who stayed in their usual shoes: 10 of 19 had an increase in at least one bone (P = 0.009 vs control)Ridge 2013B+RCT in 320 novice runners: 2 weeks of gait retraining with real-time visual feedback aimed at lowering impact loading cut loading rates (d > 0.99) and was followed by 16% vs 38% running injury over 12 months (HR 0.38, 95% CI 0.25-0.59, 62% lower risk) versus treadmill running without feedbackChan 2018B550 injured recreational runners on an instrumented treadmill: strike pattern and peak vertical force were the only biomechanical variables that set one injury location apartMidfoot strike went with Achilles tendon injuries (OR 2.27), forefoot strike with posterior lower-leg injuries (OR 2.59), peak vGRF weakly with hip injuries (OR 1.14); loading rate and cadence did…Hollander 2021B+827 US Military Academy cadets followed through 9 weeks of basic training: the longest ground contact times (>0.42 s) went with 2.15× the risk of overuse lower-extremity injury after adjustment, the shortest stride length with 45% more overuse injury (univariate), and foot strike pattern and cadence were not associated with injuryHelton 2025B+Systematic review of 13 studies on foot strike technique and running-related injury: low evidence for any relationship; 3 of 6 categorical studies found more retrospective injury in rearfoot strikers and 1 found more risk with mid/forefoot strike, but these were very low quality; only 1 of 7 continuous-measure studies found a relationshipBurke 2021C+Narrative critique of the case for switching from a rearfoot to a mid- or forefoot strike: the authors conclude that the switch does not improve running economy, does not eliminate the impact at foot-ground contact and does not reduce the risk of running-related injury; the rearfoot strike is clearly the more prevalent patternHamill 2017B-In 52 collegiate cross-country runners, about 74% had a moderate or severe injury each year; habitual rearfoot strikers had about twice the rate of repetitive stress injuries of habitual forefoot strikers, while traumatic injury rates did not differ significantlyThe abstract names no Achilles, calf or metatarsal resultsDaoud 2012A-Review of 53 studies: non-rearfoot strikers report fewer repetitive stress injuries in retrospective data only, habitual non-rearfoot and rearfoot runners have the same running economy, imposing a non-rearfoot strike on rearfoot runners worsens economy in the immediate term, and loading shifts from knee to ankleChanging strike pattern cannot be recommended for an uninjured rearfoot runnerAnderson 2020A-Meta-analysis of 16 studies in adult distance runners: forefoot strikers land with a plantar-flexed ankle and a more flexed knee, and rearfoot strikers have higher vertical loading rates; the abstract reports kinematics and loading rate onlyRunning economy was not an outcome, and no knee-versus-Achilles load comparison is reportedAlmeida 2015BNatural forefoot-striking women (n=19) had lower patellofemoral contact force (4.3 vs 5.1 body weights) and stress (11.1 vs 13.0 MPa) and a lower knee frontal-plane moment than matched rearfoot strikers (n=19) at 4 m/s, but a higher ankle plantarflexor moment (3.12 vs 2.54 N·m/kg) and Achilles tendon force (6.3 vs 5.1 body weights)Kulmala 2013BHabitual rearfoot and forefoot strikers at 4.5 m/s did the same total lower-limb work and average power; the load sat at the knee in rearfoot and at the ankle in forefoot running, and rearfoot strikers switched to an imposed forefoot strike raised the ankle internal rotation moment by 33%, kept knee abduction moments 48.5% above habitual forefoot strikers and raised total positive limb power by 17%Stearne 2014BHabitual rearfoot (n=19) and forefoot (n=18) runners on a treadmill at 3.0, 3.5 and 4.0 m/s: with their own pattern the groups did not differ in oxygen cost or carbohydrate use; switching to forefoot raised both in rearfoot runners at 3.0 and 3.5 m/s, switching to rearfoot changed nothing in forefoot runners, and at 4.0 m/s the forefoot pattern cost more oxygen with no difference in carbohydrate shareGruber 2013B2017 IAAF World Championship men's 10,000 m final (top 12 finishers, filmed on six laps): no rearfoot strikes at all, forefoot and midfoot strikers in similar numbers with similar finishing times, and no change in pattern even when speed fell and contact time rose mid-raceHanley 2024A-Systematic review and meta-analysis of overground distance running (> 10 km, 12 studies): 79% of runners rearfoot strike early and 86% with increased distance; 11% change pattern, 84% of those from non-rearfoot to rearfoot; evidence for a performance advantage of non-rearfoot striking is inconclusive (5 studies for, 1 in women only, 4 no benefit, none favouring rearfoot)Bovalino & Kingsley 2021BAt 8.1 km of a mid-size city marathon (1991 runners classified), 93.67% were heel strikers; foot-strike class differed with race position (Kruskal-Wallis P <.0001), with faster runners less likely to heel strike, and it did not differ by genderKasmer 2013B2017 IAAF World Championship marathons (71 men, 78 women filmed at ~8.5, 19, 29.5 and 40 km): rearfoot striking was the most common pattern at every point (never below 54% of men or 67% of women), it did not separate top from bottom halves of the men's field, and more than 75% of athletes kept the same pattern across lapsHanley 2019BFilmed at 15 km of an elite-level half marathon (283 runners analysed): 74.9% rearfoot, 23.7% midfoot and 1.4% forefoot strikers; in the fastest group of 50 the split was 62.0 / 36.0 / 2.0%, so midfoot striking became more common with speed, and rearfoot contact time was longer than midfoot + forefoot (200.0 vs 183.0 ms)Hasegawa 2007B90, 120 and 150 g/h of glucose + fructose over 3 h of cycling in trained men: exogenous oxidation rose with the dose (1.23 → 1.48 → 1.62 g/min), whole-body carbohydrate oxidation did not rise from 120 to 150 g/h (2.6 g/min both), exercise capacity afterwards did not differ between 90, 120 and 150 g/h, and the modelled best dose was 107 g/h (95% CI 92-122) with wide individual variationMartyn 2026B+A single run more than 10% longer than the longest run of the previous 30 days raised the rate of overuse running injury (HRR 1.52-2.28 by size of spike) in 5205 adult runners followed for 18 months with Garmin data; week-to-week change showed no relationFrandsen 2025BRecreational (half-)marathon runners (n=997): higher weekly volume and a longer longest run went with faster finish times; for the marathon a longest run under 25 km went with a slower finish (β 13.44, units not stated, likely minutes); no training characteristic was associated with injuryFokkema 2020BElite cyclists, 7 weeks of intervals 3×/week in season with moderate-intensity volume cut by ~33% (~5 h/week) or kept: fresh ~20-min time trial improved (+3% and +2%), the time trial after a 120-min preload did not improve significantly overall (p = 0.19), and preload lactate fell only where volume was keptChristensen 2024BDurability improved similarly after 10 weeks of low-intensity (6.8 h/week) or high-intensity (1.6 h/week) cycling in sedentary and recreationally active adults, measured over a 3-h ride at 48% VO2max; only high-intensity training raised VO2max, and the changes in drift were smallMatomäki 2023BDurability — how to measure it: the fatiguing protocol shapes the result (higher relative intensity and longer duration deteriorate baseline measures more), and nutrition and environment must be controlled for a durability number to be repeatable or comparableHunter 2025B+Training twice every second day with low glycogen versus once daily for 3 weeks in well-trained cyclists (pair-matched, randomised): interval power was lower (297 vs 323 W), the time trial improved ~10% in both groups, and fat oxidation rose with the stacked scheduleHulston 2010BTwice every second day versus once daily for 3 weeks in trained cyclists: the same two sessions (100-min steady ride + 8 × 5 min) stacked 1-2 h apart raised fat oxidation and oxidative enzymes, compromised the interval session, and improved a 60-min time trial by ~10%The same as training once a dayYeo 2008A-Morning versus evening exercise and sleepSystematic review (25 studies, 4233 participants) with a meta-analysis of 16 RCTs (n=611): no clear overall advantage of morning over evening exercise for most sleep outcomes; evening/night exercise…Souabni 2026C+Fat-free mass accretion — limits, targets and best practices (narrative review): drug-free men typically gain ~1.4 kg of fat-free mass over 12 weeks of resistance training (IQR 1-2 kg); practical FFM-index ceiling ~28.5; modest surplus of 0.1-0.25% body weight gain per week, protein 1.6-2.2 g/kg/dTrexler 2026C+Off-season nutrition for natural bodybuilders (narrative review): a ~10-20% energy surplus aiming at ~0.25-0.5% of body weight gained per week for novice/intermediate lifters, more conservative for advanced ones; protein 1.6-2.2 g/kg/day in 3-6 meals of 0.40-0.55 g/kgIraki 2019B+"Much Ado About Zone 2" — a narrative review from the Gurd and Gibala groups: current evidence does not support Zone 2 as the optimal intensity for improving mitochondrial or fatty-acid oxidative capacity; the popular claim rests largely on observational data from elite endurance athletes, and higher intensities matter more at lower training volumesStoroschuk 2025B+3 months of HIIT vs moderate-intensity continuous training (MICT) in obese adults: VO2peak +16% vs +6%; maximal fat oxidation rose only after HIIT; mitochondrial respiration rose in both (+36% vs +67%, no significant difference); after 4 months of follow-up only the HIIT group kept higher VO2peak and fat oxidationVaccari 2020A-Physical recovery modalities in competitive and elite endurance athletesNetwork meta-analysis of 16 RCTs (273 participants): no modality outperformed passive recovery on soreness, creatine kinase or sport-specific performance; compression garments do not improve…Jin 2026B+Weight gain in elite athletes (8-12 weeks, 4 extra strength sessions a week): a counselled energy surplus raised body weight more (3.9% vs 1.5%) but mostly as fat (+15% vs +3% fat mass); lean-mass gain did not differ from eating ad libitum, and 40 m sprint 'decreased' in the counselled group (read as slower; the abstract gives no times)Garthe 2013BMaintenance vs 5% vs 15% energy surplus for 8 weeks in trained lifters: no group evidence for more muscle thickness or squat 1RM with a bigger surplus, more skinfold gain with the high surplus, and body-mass gain predicted fat (skinfold) gain far better than muscle gainHelms 2023