Power Development

1. Power Development Aaron Wellman University of Michigan Football Director of Strength and Conditioning

2. Youth Sport Injuries Dr James Andrews… • Five to sevenfold increase in injury rates in youth sports • Many with mature-type injuries Why? • Specialization • Almost ½ of sports injuries in adolescents stem from overuse • Professionalism • Training kids as if they are professional athletes Dr. Andrews recommendations • Kids need at least 2 months off each year to recover from a specific sport, preferably 3 to 4 months.

3. Don’t confuse reading with believing! -Martin Rooney Programs based on “Science.” Special Warfare Community Science has been proven wrong over and over again! Base Your Program on Scientific Principles AND Pragmatic Experience The ART of S&C is what sets you apart!

4. What “Science” Says About Fatigue… 2012 study by Noakes, Frontiers in Physiology Archibald Hill (English physiologist) Peripheral Model of Fatigue Assumed that lactic acid is only produced under anaerobic conditions and that increased muscle lactate concentrations are the cause of peripheral fatigue. We now know that BOTH of these assumptions are invalid. Acidosis has little or no effect on the strength of contractions in skeletal muscle of mammals (Bandschapp, et. Al.)

5. Fatigue Noakes suggests: Exercise performance is not limited by a failure of skeletal muscle. Rather, exercise performance is regulated in anticipation specifically to insure that no such biological failure can occur. Believes fatigue is not a physical event but an emotion used by the brain to regulate exercise performance. He notes in the final stages of any given race, perhaps as many as 65% of the muscle fibers in both the leading athletes’ legs are inactive and do not contribute to the physical effort. Why? Brain-generated sensations of fatigue place a moveable limit on performance. Conclusions…

6. Fatigue Noakes Concludes with the following hypothesis… In the case of a close finish, physiology does not determine who wins. He suggests, that, because of the sensations of fatigue, which originally evolved to prevent damage or even death to the body, the brains of the second placed finishers accept defeat in the final stages. He suggests that the winner is the athlete for whom defeat is the least acceptable rationalization and who is able to withstand the unpleasant feelings of fatigue the most successfully.

7. Our Philosophy Maximize Speed, Strength, and Power while Minimizing Orthopedic Stress (certain exercises possess more inherent risk than others) • Demand Investment: Program has to challenge them • Coach: Technique, Effort, Discipline, Accountability, Toughness • Motivation: (Red Shirts, Victors Board, Before and After Photos) • Basic, Progressive Exercises • Prepare!

8. Power Development • Power Defined • Which Exercises? • Post-Activation Potentiation (PAP) 4. Programming

9. Strength vs. Power • Strength: The ability to exert a maximal force against a resistance (independent of speed) • Power: The ability to exert a maximal amount of force in the shortest possible time interval. Power (P) = Force (F) x Velocity (V) Simplifying: • Get Stronger and/or • Get Faster

10. Power Development To some degree every athlete will need to develop power! “Even a marathon runner needs to sprint to the finish line.” Louie Simmons An athlete’s ability to display a high level of explosive power is believed to be one of the most important factors in determining athletic success. (McBride)

11. A Fundamental Relationship Exists Between Strength and Power • Stronger athletes possess favorable neuromuscular characteristics that form the basis for superior power production. (Cormie) • The strength level of an athlete will always dictate the upper limit of their potential to generate maximal power because the ability to generate force rapidly is of little benefit is maximal force is low. • An athlete does not have to do an inordinate amount of power training until a solid foundation of strength is developed An increase in strength directly effects power output.

12. A Fundamental Relationship Exists BetweenStrength and Power Your choice of resistance exercise will lead to velocity-specific adaptations. • Heavy Loads: improve the high-force, low-velocity portion of the force-velocity curve • Light Loads: improve the low-force, high-velocity portion of the force-velocity curve. Train both high-force AND high-velocity movements!

13. Force-Velocity Relationship

14. Force-Velocity-Power Relationship

15. Effect of Training on F-V Curve

16. Choosing Velocity Appropriate Exercises High Force/Low Velocity (Lower Body) • Squat Variations (Front, Back, Box, Chains, Single Leg) • Hex Bar Deadlift Low Force/High Velocity (Lower Body) • Keiser Speed Squat • Olympic Variations • Hex Bar Power Pull • Squat Jumps • KB Swings

17. What Are The Best ExercisesFor Developing Power?

18. Hex Bar vs. Power Clean • Swinton looked at power outputs of 19 male powerlifters and found average peak power output of hex bar (speed) deadlift to be 4,872W, with individual outputs as 6,145W. • Winchester et. al. and Cormie et. al. reported maximum peak power output values of 4,230 W and 4,900W respectively for college athletes performing the power clean. Performing “traditional” exercises with submaximal loads may be ineffective for developing muscular power because of the period of deceleration prior to the barbell stopping.

19. Hex Bar Power Pull • Swinton (2012) compared hex bar ‘power pull’ to barbell squat jumps. • Hex bar produced higher power outputs than squat jumps at 20%, 40%, and 60% of 1 RM • Highest power output was recorded with 20% of 1 RM Deadlift

20. Power Outputs • Kawamori (2005) peak power outputs highest for hang clean @ 70% of 1 RM power clean. • Intensities between 50-90% Not Significantly Different! • Kilduff (2007) did not find any significant differences in peak power between loads of 50-90%. • Comfort (2011) looked at power outputs using 60% 1 RM PC load for each.

21. Rate of Force Development • Comfort (2009 & 2011) compared rate of force development • Both studies found RFD was maximized by mid-thigh clean and mid-thigh clean pull.

22. UM Football (Athlete A) Compared movements and recorded highest peak power outputs of each • CM Squat Jump • Hang Clean (135, 155, 185, 205, 225) • Hang Clean Pull • Hex Bar Power Pull (No Counter Movement!)

23. UM Football (Athlete B) Compared movements and recorded highest peak power outputs of each • CM Squat Jump • Hang Clean (135, 155, 185, 205, 225) • Hang Clean Pull • Hex Bar Power Pull (No Counter Movement!)

24. Hex Bar Power Pull

25. Hex Bar Power Pull

26. Hex Bar Power Pull: From Pad

27. Hex Bar Power Pull: From Pad

28. Calculating Power Using Vertical (CMJ) Jump Johnson & Bahamonde Formula (1996) Power-peak (W) = 78.6 · VJ (cm) + 60.3 · mass (kg) - 15.3 · height (cm) - 1,308 Power-avg. (W) = 43.8 · VJ (cm) + 32.7 · mass (kg) - 16.8 · height (cm) + 431

29. UM Power Development • Generally performed following proper warm-up at beginning of workout, preferably in the absence of fatigue. • No more than 3 reps per set (power output stays at or above 90% of Pmax) • Train both max strength and speed strength in a manner which allows for optimal rest, recovery, and adaptation to occur. • Certain exercises are better suited than others… (explosive pushup vs. bench press) • Actual Speed vs. Intent to Move Fast • Behm and Sale (1993) proposed that it’s the intention to move a given load quickly, not actual speed that determines training response.

30. Athletic men performed jump squats with either 30% (JS30)or 80% (JS80)of 1 RM Squat Agility test, 20 m sprint and jump squats with 30, 55, and 80% were done pre- and post- Results The JS30 group had improved velocity capabilities regardless of the load, which did not occur in the JS80 groups. JS80 group showed improved force capabilities, with no effect (in some cases a negative effect) on velocity capabilities. JS80 group significantly improved their agility times but performed significantly worse in 20 m sprint.

31. Heavy resistance training may increase initial acceleration while velocity is slow, but light resistance increases acceleration capabilities during higher velocity movements. Squat max correlates well to the first 15 m of sprinting in high school aged athletes. (Keiner, Wirth, and Schmidtbleicher, 2012)

32. Post-Activation Potentiation

33. Post-activation Potentiation (PAP) PAP is induced by a voluntary conditioning contraction performed typically at a maximal or near-maximal intensity, and has consistently been shown to increase both peak force and rate of force development during subsequent twitch contractions. • Examples: • Barbell Squat > Weighted Vertical Jump • Hex Bar Power Pull > Body Wt. Vertical Jump Muscular performance characteristics are acutely enhanced as a result of their contractile history.

34. Post-activation Potentiation How does PAP work…from scientific standpoint? • Phosphorylation of myosin regulatory chains: max contraction alters structure of myosin head and leads to increased sensitivity of myosin head to ca+ ions released by the sarcoplasmic reticulum. • Increased recruitment of higher order motor units: max contraction activates adjacent motoneurons via afferent neural volley and H-Reflex enhancement which increases neurotransmission. • Change in pennation angle: max contraction decreases pennation angle which increases force transmission to tendon. (Tillin and Bishop, 2009)

35. Post-activation Potentiation How does PAP work…from Non-scientific standpoint? When you perform a 3-5 RM followed by a light explosive set…to your nervous system, it’s like “lifting a ½ can of water when you think it’s full.” -Verkhoshansky

36. PAP: What We Need to Know… • It’s been shown that contractions of maximal or near maximal (>80% of dynamic or isometric MVC) optimize PAP. (Sale) (Rahimi) (Saez et. al) • Peak PAP is achieved immediately after a conditioning contraction, but instantly begins to decrease. (Vandervoot, et, al., Gossen and Sale, Baudry and Duchateau) • Fatigue is also present immediately after! • Fatigue seems more dominant in the early stages of recovery, and consequently, performance of subsequent voluntary activity is diminished or unchanged. Fatigue subsides at a faster rate than PAP, so potentiation of performance can be realized at some point during the recovery period.

37. Post-activation Potentiation (PAP) The conditioning contraction may also cause fatigue, and it’s the balance between PAP and fatigue that will determine the net effect on performance of a subsequent explosive activity. (Robbins)

38. Post-activation Potentiation (PAP) • Fatigue diminishes force-generating capabilities, while PAP potentiates or excites them. • PAP and fatigue develop and dissipate at different rates

39. Post-activation Potentiation (PAP) This relationship is affected by a combination of factors including: (Robbins) • Volume of conditioning contraction (sets, reps and rest interval between sets) • Intensity of conditioning contraction (contractions >80% optimize PAP) • Type of conditioning contraction (dynamic or isometric) • Subject characteristics (strength, fiber-type distribution, training status) • Type of subsequent activity

40. Post-activation Potentiation (PAP) • Volume of conditioning contraction • PAP may develop faster than fatigue, so possible to use immediately after a low volume conditioning contraction. • As CC volume increases so does fatigue, so rest interval may be required before PAP is realized. French et. al. (2003) • Peak torque increased after 3x3 sec. isometric contractions • Peak torque significantly decreased after 5x3 sec. isometric contractions The specific recovery period required for different CC volumes has yet to be determined!

41. Post-activation Potentiation (PAP) 2. Intensity of conditioning contraction • The consensus is that maximal contractions (> 80%) optimize PAP. • Type of conditioning contraction • Doesn’t seem to be a clear relationship between contraction type (isometric vs. dynamic) and PAP response. • Studies on each type have shown both significant increases and little to no changes in subsequent explosive activity. • We typically use 1-3 reps at 85-90% immediately (0-60 sec) followed by explosive movement: Hex Bar concentric only Deadlift Body Weight VJ

42. Post-activation Potentiation (PAP) • Subject Characteristics Muscular Strength: • Gourgoulis (2003) found 4.0% increase in CMJ height after 5 sets of back squats in those would could squat 350 lbs or more. • Only .4% increase in those who could not squat 350 lbs. • Kilduff (2007) also reported a correlation between CMJ peak power potentiation 12 minutes after a 3 RM Back squat WHY?? Possibly due to subject fiber-type distribution. Those with a higher percentage of Type II fibers may achieve greater PAP responses.

43. Post-activation Potentiation (PAP) • Subject Characteristics Muscular Strength: • Gourgoulis (2003) found 4.0% increase in CMJ height after 5 sets of back squats in those would could squat 350 lbs or more. • Only .4% increase in those who could not squat 350 lbs. • Kilduff (2007) also reported a correlation between CMJ peak power potentiation 12 minutes after a 3 RM Back squat WHY?? Possibly due to subject fiber-type distribution. Those with a higher percentage of Type II fibers may achieve greater PAP responses.

44. Post-activation Potentiation (PAP) • Subject Characteristics Training Level: • Athletes accustomed to higher levels of training develop fatigue resistance, and may be more likely to realize PAP (Chiu, 2003) • Some evidence shows that PAP works better for strong athletes who are not very powerful; i.e. they have trouble converting their strength to power (Schneiker, 2006) Conclusions: Evidence suggests that individuals most likely to benefit from PAP include those with a greater muscular strength, a larger percentage of type II fibers (although fatigue may also be greater in these individuals) and a higher level of resistance training.

45. Post-activation Potentiation (PAP) 5. Type of Subsequent Activity • While a CC might enhance performance in a particular dynamic activity, it may have no effect or decrease performance of another activity. • Important to match the kinematics of the CC to those of the subsequent explosive activity! • This becomes a challenge when attempting to use PAP to enhance specific explosive sporting activity (sprinting, long jump, etc)

46. Post-activation Potentiation (PAP) Implementation Heavy Bench Press > MB throw, Plyo Push Ups (select athletes only) Squats or HB Deadlift > Vertical Jumps, Split Jumps Straight Bar Deadlift, RDL > Sprints, Broad Jumps

47. Summer Template

48. Summer Program Anatomical Adaptation (Weeks 1-2) Purpose: • To prepare the athlete for high-intensity training that takes place during the next phase. • Prepare the muscles tendons and ligaments for the Max Strength Phase Weight Training: • Use a variety of exercises at sub-maximal loads • Circuits work well in this phase Running: • Use sub-maximal intervals: full gassers, ½ gassers, 110’s, 200’s, 300’s Jumping: • High frequency/Low amplitude Jumps (hops): Line jumps, dot drill, QF ladder jumps

49. Summer Program Max Strength: 3-5 (Weeks 3-6) Purpose: • To develop max strength in the Upper Body Pressing movements and Compound Lower Body movements. Weight Training: • Train these exercises in the 3-5 rep range • Use Relative Intensities to program training Running: • Resisted Sprints Jumping: • CMJ, Box Jumps, SL Box hops

50. Summer Program Power: (Weeks 7-10) Purpose: • To develop max power in the Upper Body Pressing movements and Compound Lower Body movements. Weight Training: • Train at MaxP (HVP = MaxP -10%, LVP = MaxP + 10%) • Include PAP Running: • Sprints out of 3 pt. or position stance Jumping: • Plyos (< .25 sec GCT)