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.
57 entries in Intervals & intensity
COlympiatoppen's Intensity Scale, Version 2 (2024)The Norwegian elite-sport centre's eight-zone I-scale (I-1 to I-8) with RPE, %HRmax, %VO2max, lactate, breathing, time to exhaustion, interval and rest rules, an HRmax field test and national-team…Olympiatoppen (Skarli 2024B-In junior skiers 5–10-minute intervals totalling 40–45 minutes improved performance more than 2–4-minute intervals totalling 15–20 minutesThe longer reps came with twice the work timeSandbakk 2013B+At a fixed power equal to that at VO2max, 30-second work periods with 15-second recoveries gave more work and more time at or above 90% of VO2peak before exhaustion than long work periods at the same powerRønnestad & Hansen 2016BOver 10 weeks, effort-matched short intervals raised VO2max by 8.7% against 2.6% for long intervals in cyclistsRønnestad 2015BSelf-paced intervals with 1:1 rest ended at the same RPE (about 17) and lactate (about 4.5 mmol/L) whether the reps were 1, 2, 4 or 6 minutesBut 1-minute reps reached only 82% of VO2max against about 92% for 2–6-minute repsSeiler & Sjursen 2004A-Effect of training on lactate/ventilatory thresholds: a meta-analysisLonderee 1997BEffects of different interval-training programs on cycling time-trial performanceStepto 1999BInterval training program optimization in highly trained endurance cyclistsLaursen 2002B+Aerobic high-intensity intervals are superior to improve VO2max compared with sprint intervals in well-trained menHov 2022A-Which Training Intensity Distribution Intervention will Produce the Greatest Improvements in Maximal Oxygen Uptake and Time-Trial Performance in Endurance Athletes? A Systematic Review and Network Meta-analysis of Individual Participant DataRosenblat 2025B+Aerobic high-intensity intervals improve VO2max more than moderate trainingHelgerud 2007A-The Additional Effect of Training Above the Maximal Metabolic Steady State on VO2peak, Wpeak and Time-Trial Performance in Endurance-Trained Athletes: A Systematic Review, Meta-analysis, and Reality CheckRosenblat 2023BEffect of 4 wk of deep water run training on running performanceBushman 1997BInfluence of water run training on the maintenance of aerobic performanceWilber 1996BThe 10-20-30 training concept improves performance and health profile in moderately trained runnersGunnarsson & Bangsbo 2012BReduced volume and increased training intensity elevate muscle Na+-K+ pump α2-subunit expression as well as short- and long-term work capacity in humansBangsbo 2009BModerate association of anthropometry, but not training volume, with race performance in male ultraendurance cyclistsKnechtle 2009BEffects of Low and High Cadence Interval Training on Power Output in Flat and Uphill Cycling Time-TrialsNimmerichter 2011BAnthropometric and Training Variables Related to Half-Marathon Running Performance in Recreational Female RunnersKnechtle 2011BHow Do Endurance Runners Actually Train? Relationship with Competition PerformanceEsteve-Lanao 2005C+Interval Training for Performance: A Scientific and Empirical Practice. Special Recommendations for Middle- and Long-Distance Running. Part I: Aerobic Interval TrainingBillat 2001B+Training to Enhance the Physiological Determinants of Long-Distance Running Performance: Can Valid Recommendations be Given to Runners and Coaches Based on Current Scientific Knowledge?Midgley 2007BInterval training at 95% and 100% of the velocity at VO2max: effects on aerobic physiological indexes and running performanceDenadai 2006B+Training Periodization, Methods, Intensity Distribution, and Volume in Highly Trained and Elite Distance Runners: A Systematic ReviewCasado 2022BTraining-Intensity Distribution During an Ironman Season: Relationship With Competition PerformanceMuñoz 2014B+The Effect of Periodization and Training Intensity Distribution on Middle- and Long-Distance Running Performance: A Systematic ReviewKenneally 2018B+Crossing the Golden Training Divide: The Science and Practice of Training World-Class 800- and 1500-m RunnersHaugen 2021AIn previously inactive adults, interval training reaches 80% of its VO₂max gain in about 11 minutes a session and flattens by ~23; steady moderate training needs ~52 minutes for its 80% and had not flattened at the longest dose studiedA dose–response meta-analysis of 69 RCTsMattioni Maturana 2026B+Easy sessions run AT the first threshold (the top of the moderate domain) gave the same 6-week gains as running 10-15% below itWith a somewhat higher psychophysiological load that stayed within acceptable limitsGuimarães 2026BFast-start/decreasing-speed (DEC) and varied-intensity (VAR) long intervals both accumulate more time ≥90% VO₂peak than speed- and duration-matched constant-speed intervals (CON) in well-trained XC skiersAnd are equivalent to each otherRønnestad BR 2022A-Effects of 16 weeks of pyramidal and polarized training intensity distributions in well-trained endurance runnersSeasonal TID SEQUENCINGFilipas 2022BThe Road to Gold: Training and Peaking Characteristics in the Year Prior to a Gold Medal Endurance Performance11 Olympic/World-champion XC skiers and biathletes trained ~800 h / 500 sessions in their gold-medal year; ~90% of endurance training time below the first lactate threshold, 10% above; volume fell…Tønnessen E 2014BSkeletal Muscle Characteristics Among Distance Runners: A 20-Year Follow-up Study28 men who were highly trained distance runners in 1966-74, re-biopsied ~20 years later: the 11 who had stayed highly trained (>70% type I at baseline) were unchanged on average, while the 10…Trappe 1995BMuscle Fiber Composition and Enzyme Activities of Elite Distance RunnersGastrocnemius biopsies in 14 elite distance runners, 18 middle-distance runners and 19 untrained men: elite runners had 79% slow-twitch fibers, ST fibers 22% larger than FT, and SDH activity 3.4×…Costill DL 1976BMyosin Heavy Chain IIX Overshoot in Human Skeletal MuscleIn sedentary men, 3 months of heavy resistance training cut vastus lateralis MHC IIX from 9.3% to 2.0% (IIA 42.4% → 49.6%); after 3 months of detraining MHC IIX overshot to 17.2%, above the…Andersen JL & Aagaard P 2000C+The Effects of Endurance, Strength, and Power Training on Muscle Fiber Type ShiftingNarrative review: IIA↔IIX interconversion is well established; whether type I and type II interconvert is disputed; high-velocity/ballistic work is discussed as a route toward more type II…Wilson JM 2012BMuscle Fiber Typology Substantially Influences Time to Recover from High-Intensity ExerciseAfter 3 × 30-s Wingates, knee-extension MVC torque had fully recovered in 20 min in slow-typology men but was still not recovered 5 h later in fast-typology men (power drop −61% vs −41%); n=20Lievens E 2020BMuscle Metabolic and Neuromuscular Determinants of Fatigue During Cycling in Different Exercise Intensity DomainsBlack MI 2017BBreak Point of Serum Creatine Kinase Release After Endurance Exercise15 healthy young men, 90 min cycling on 3 consecutive days: CK rose from 3 h after the first session; peak CK split into high (>500 IU/l) and low (<300 IU/l) responders, so the "break point" of CK…Totsuka M 2002BQuantifying Training Intensity Distribution in Elite Endurance Athletes: Is There Evidence for an "Optimal" Distribution?11 nationally competitive junior XC skiers over 32 days: ~75% of endurance sessions in zone 1, 6-8% in zone 2, 17-18% in zone 3 — a polarized pattern with little training at thresholdSeiler KS & Kjerland GØ 2006