Hi guys, some little reading if you are into all the hype, well most of us riding with power are into it Summary of Intervals, Thresholds, and Long Slow Distance: the Role of Intensity and Duration in Endurance Training -- Authors Stephen Seiler and Espen Tønnessen TERMS HIT= High Intensity Aerobic Interval Training (1-8mins of repeated bouts at 90-100% of vo2max with 1 to 5 mins of rest) CT=Continuous Training at Lower Intensity (at or below LT1 for 30 mins or more) The 3 Polarized Zones P1=Zone between 50% vo2max and VT1/LT1 intensity (2-2.5mmol) P2=Zone between VT1/LT1 and VT2/LT2 intensity (2-2.5mmol-4mmol) P3=Zone between LT2/VT2 4mmol+ and below 100% vo2max NOTE: MAP and the ANAEROBIC Zones are to the right of P3 (e.g. Coggan's L5/6/7) A. On differences between HIT and CT 1. HIT has been around since the 1920s in various forms (its not new!) 2. Untrained athletes benefit equally from any intervention. 3. Lots of inconclusive studies regarding adaptations from HIT vs CT from 70s through 90s for trained athletes. 4. When there are differences results of more recent studies lean towards CT promoting peripheral adaptations whilst HIT promotes central. 5. HIT intensity studies comparing 30sx175% MAP, 4min@85% MAP, 8min@80% MAP showed 4min@85% yielded best results for endurance performance. 6. HIT volume studies found that 1xLT, 4xCT, 1xHIT was not bettered with more HIT and lead to overtraining/reaching symptoms. B. Intensity and duration of HIT and CT 7. An interesting aside, Lactate concentrations at MLSS are higher in activities activating less muscle mass. 8. Ultimately the training targets for training interventions are cells. 9. But sadly, we still don't know the impact training duration/intensity has on intercellular signalling and protein synthesis. 10. After about 10 workouts of same intensity x duration there will be no increase in AMPK. ie, we adapt to it and then adaptations halt. 11. Glycogen depletion can enhance adaptations to training (!) 12. Antioxidants can reduce adaptations to training. 13. There is likely substantial overlap of effects between increasing intensity and increasing duration of a workout. 14. Table 2 - pros/cons of increasing intensity from 70 to 90% of vo2max for any given duration (tempo to just above threshold) +ves: increase stroke volume, lactate shift right, angiogenesis (more blood vessels) -ves: premature fatigue central and peripheral, reduce stimulus for fat burning systems, inadequate stimulus of slowtwitch (?) 15. Table 3 - pros/cons of increasing duration from 45 to 120 mins for exercise at 60-70% of vo2max (tempo intensity) +ves: improved movement economy, enhanced fat oxidation, right shift in lacte turnpoint, mitochondrial synthesis (?), increased oxidative enzymes -ves: might be maladaptive pedalling for higher intensity, accumulation of fatigue if carb insufficient C. What do Elite Athletes do ? 16. 1991 NZ Marathoners 8% intervals, rest at 77% of 4mmol (OBLA), roughly 60-65% vo2max 17. 1995 100/200m swimmers (event of 1-2mins max) swam 77% of their 1150km of traing below LT1 18. 1998 German 2k rowers (6-7min event); no training at lactate threshold, 4% at 6-12mmol (!), rest at < 2mmol. 19. 2001 French/Portugese marathoners ran 78% of their miles below LT1. 20. 2003 Kenyan 5/10km runners ran 85% below LT (not clear if 1 or 2) 21. 2005 8 spanish runners trained over 6 months with distribution; P1 71%, P2 21%, P3 8%; -ve correlation if dropped P1 time. 22. 1970-1990 Norwegian Rowers training volumes increased 20% mostly low intensity, high intensity dropped by a third, replaced by intervals as 85-95% of vo2max. Performance improved by roughly 10% over this period. 23. 2009 German rowers performed 95% below 2mmol, the 5% of P2+P3 work shifted to >P3 intensities in competition prep phases. 24. 2007 Spanish U23 cyclists Nov-Jun; winter = P1 164h P2 42h P3 5h, spring = P1 182h P2 57h P3 21h; perf plateaud during spring cycle 25. 2002 German TP Sydney Gold medal team, 200 days leading to Olys; P1 140d P2 20d P3 6d 26. 2006 12 17yr old Norwegian XC Skiers; P1 91% P2 6% P3 2.6% NOTE: P3 may be underreported due to use of HR tiz. D. An 80:20 rule and why it is so prevalent ? 27. Studies of elite athletes show remarkable consistency with 80% of training done below LT1 28. Elite athletes training 10-12 times per week are likely to spend 1-3 sessions above MLSS 29. Seiler and Kirkland propose P1 75-80% P2 5% and P3 15-20% recognising that; 30. There is some variability in how the remaining 20% is spent between P2 and P3 by sport 31. Large volumes of training at low intensity might be optimal for maximizing peripheral adaptations 32. Small volumes of high intensity training fulfill the need for optimizing signaling for enhanced cardiac function and buffer capacity 33. Athletes may migrate towards a strategy where longer duration is substituted for higher intensity to reduce the stress reactions associated with training and facilitate rapid recovery from frequent training 34. Note; There is probably considerable variation between athletes for the size of the P1 zone. 35. Note; Some athletes train much closer to LT1 because the technique required is difficult at lower intensities. 36. Running imposes severe ballistic loading stress that is not present in cycling or swimming. There seems to be a strong inverse relationship between tolerated training volume and degree of eccentric or ballistic stress of the sport 37. Swimming, rowing, and cross-country skiing are all highly technical events with movement patterns that do not draw on the genetically pre-programmed motor pathways of running. Thus high volumes of training may be as important for technical mastery as for physiological adaptation in these disciplines 38. Rowers and speed skaters do less movement-specific training than most other athletes, but they accumulate substantial additional hours of strength training and other forms of endurance training. E. Is 80:20 optimal, or would more threshold + HIT give a better 'bang for buck' ? 39. Many studies on this in the last 10 years. 40. 2001 Junior XC Skiers 12h/week high vs 16h/week moderate - Despite 60 % more training volume in MOD and perhaps 400 % more training at lactate threshold or above in HIGH, physiological and performance changes were modest in both groups of already well-trained athletes 41. 1999 14 XC Skiers 1year with 16% at LT, 7 non-responders changed to High Intensity in Year 2; no change in performance development 42. 2007 elite distance runners, 6xPolarised v 6xThreshold for 5 months; Polarised showed significantly greater race time; -157 ± 13 vs ‑122 ± 7 s 43. 2008 elite rowers; 9xLow intensity v 9 70low:30high; low had greater rightshift of lactate curve, high preserved AWC, results similar. 44. Looking at collected data they noticed a trend for recreational athletes to fall into a training black hole; despite plan prescribing distribution of intensities amateurs did low intensity workouts too high and high intensity workouts too low. 45. 2001 The recreational group that trained more polarized, with more training time at lower intensity, actually improved their 10-km performance significantly more at 7 and 11 wk. 46. 4-min work duration and 2-min recovery duration combine to give the highest physiological response and maintained speed "to counter athletes falling into black hole" (my words) 47. Soccer pro becomes elite cyclist; did 2.5 years of nr lactate threshold/vo2max 10h each week then switched to 20h/week polarised; FTP/LT power increased 14% in first 18 weeks. 48. Pentathlete becomes runner; <2003 low-volumne high-intensity to polarised; CV/LT speed increased by 5% F. Conclusions 49. There is reasonable evidence that an ~80:20 ratio of low to high intensity training (HIT) gives excellent long-term results among endurance athletes training daily. 50. Low intensity (typically below 2 mM blood lactate), longer duration training is effective in stimulating physiological adaptations and should not be viewed as wasted training time.