Advances in Cross-training:

The Role of Deep Water & Antigravity Treadmill Running to

Prevent Running Injuries

Mark A. Harrast, M.D.Medical Director, Sports Medicine Center at Husky StadiumDirector, PM&R Sports Medicine FellowshipMedical Director, Seattle MarathonClinical ProfessorUniversity of Washington

I have nothing to disclose.

Objectives

1. Introduce two sport-specific cross training methods:a) Deep Water Running (DWR) b) Antigravity Treadmill Training (ATT)

2. Understand the physiology, biomechanics, and performance-related research re these methods

3. Keep it practical

Effective Cross-training

1. Training pattern equivalent intensity & duration to original exercise mode

2. Replicate the ROM and muscle recruitment patterns

Forms of Cross-training(for the runner)

SwimmingCycling

EllipticalDeep Water Running (DWR)

Anti-gravity treadmill training (ATT)

Deep Water RunningRunning in the deep end of a pool/diving well

while wearing a flotation device

Buoyancy

In order to float in water, SG<1.0.

Fat ~0.8Muscle ~1.0

Bone ~1.5-2.0

Wear a flotation device

- Assists in achieving appropriate running mechanics

- Most useful for lean body types (without it, mechanics resemble treading water or stair stepping)

- Max effectiveness: Worn near center of mass

- Increased ease of breathing by maintaining head position at neutral

9

Physiologic Parameters of DWR & Treadmill Running

1. Heart rate2. VO23. Substrate utilization4. Muscle fiber type

Heart RateDWR < treadmill running

Water immersion below thermoneutral temp:

a)peripheral vasoconstriction central blood volume SV & HR to maintain CO

a)Stimulation of skin cold receptors vagal activity

VO2 MaxDWR < treadmill running

Higher in those with previous running experience(& possible better mechanics)

Still adequate for training and CV fitness

•Reduced VO2 Max:a) water temp muscle temps slows

muscle enzyme activityb) Muscle recruitment pattern differences

i. Smaller muscle mass of upper body usedii. Calves are used less (no push off)iii. No antigravity muscle use since buoyant in

water

Differences in Physiologic Parameters

Nine Studies (8-20 athletes)

Nine Studies (8-20 athletes)

Treadmill DWR

VO2 Max 53.1-67.0 46.8-58.4

Max HR 183-198 157-180

Reilly, J Sports Sci 2003Reilly, J Sports Sci 2003

Is there a difference between experienced & novice runners?

In more experienced runners:1. Submax VO2, VO2Max, and HR are similar btwn DWR & TMR2. Possibly due to increased leg muscle recruitment and better adaptation to running form in the water

Azevedo 2010 J Sports SciKilding 2007 J Strength Cond Res

ADAPTATION - training effect

DWR Technique

Kilgore 2011 Coaching Athletics Quarterly; Kilgore 2012 Phys & Sports Med 40 (1): 116-26.

limited research

Guiding Training Intensity:Rating of Perceived Exertion

1-3 points higher in DWR > TMRPerception of work needs to be harder to get

the same metabolic (training) effect

Training Effect / Performance

4-8 week DWR programs,

athletes maintained: VO2max

Anaerobic thresholdLand running economy

Leg strength2 mile and 5K run performance

Bushman, Med Sci Sport Exerc 1997 Wilbur, Med Sci Sport Exerc 1996 Eyestone, A J Sport Med 1993 Hertler, Med Sci Sport Exerc 1992

McKenzie, Clin J Sport Med 1991

Bushman, Med Sci Sport Exerc 1997 Wilbur, Med Sci Sport Exerc 1996 Eyestone, A J Sport Med 1993 Hertler, Med Sci Sport Exerc 1992

McKenzie, Clin J Sport Med 1991

Can you do better than maintain?

8 week DWR program of

progressive interval training

VO2Max

2 mile run performance

Quinn 1994Michaud 1995Quinn 1994

Michaud 1995

Training Tips

1. Don’t just transmit land workouts to the pool2. Higher percentage of DWR sessions should be at a

harder effort (due to the RPE effect and performance studies)a) Include intervals, tempo, and fartlek training to

maintain fitness b) Limit steady state effort runs (not hard enough to

maintain fitness)

Sample training programs:-Liem, Truswell, Harrast 2013 Curr Sports Med Reports 12(3):200-7. -Pete Pfitzinger, MS:

- Kemibe.com/distancecoach/labreports/water.shtml- Kemibe.com/distancecoach/labreports/9wkH2O.htm

DWR Summary:Practical Recommendations

1. Gradual familiarization is important since mechanics are somewhat different.

2. Wear a flotation device.3. More interval training (harder workouts)4. DWR demonstrates a training effect, at a

minimum, to maintain, but also potentially improve performance.

Antigravity Treadmill Training (ATT)

1. Designed by NASA engineers

2. Internal scale/force plate

3. Air-filled pressure controlled chamber

4. Unweighting from 100%BW 20%BW (in 1% increments)

5. Used for rehab as well as training

Accuracy of Unloading (Body Weight %)

McNeill 2015 J Strength & Conditioning R

Not Accurate (>5% difference)

Accurate (no stat sig diff)

Fairly Accurate (<5% difference)

100%93% 90% 60%

20%28% 80% 50%

30%36% 70% 40%

Guiding Training Intensity

1. HR – the same btwn ATT and TM

2. RPE – similar btwn ATT and TM

McNeill 2015 J Sports Sci & MedicineHoffman 2011 Arch PMR Kline 2015 J Strength & Conditioning R

3. Conversion table of speeds at different BW% to get the same metabolic demand as TMR. (increase speed to get the same training effect with decreased BW%)

%BW 6mph10 min/mile

7.5mph8min/mile

10mph6min/mile

60% 6:26 5:26 4:19

70% 6:54 5:40 4:23

80% 7:36 6:18 4:55

90% 8:26 7:00 5:28

Kline 2015 J Strength & Conditioning R

Conversion Table

Biomechanics

vGRF on Land & AT1.Increases with increasing speed

2.Levels off at higher speeds

Raffalt 2013 Res Q Exercise & Sport

vGRF with Lower BW% 1.Decreases (but not

proportionally)2.Faster speeds drop >

slower speeds

Can run at a similar VO2 with significant less vGRF by lowering BW% and increasing speed

Contour plots of impact peak, active peak, &

vertical loading rate

Grabowski 2008J Applied Biomechanics 24:288-97.

Heel Striker Forces

Mid-foot Striker Forces

Grabowski 2008J Applied Biomechanics 24:288-97.

Speed BW% MetabolicPower (W/kg)

Impact Peak

(x BW)

Active Peak

3m/s(8:56pace)

100% 11.68 1.61 2.38

4m/s(6:42pace)

82% 11.68 2.1 2.27

5m/s(5:22pace)

43% 11.68 1.61 1.61

Training Tips1. For healthy runners:

a) Keep BW% (85-95%) and speeds high to normalize motor patterns (most sport specific)

b) Supplement land running with HIIT or faster paced intervals/tempo runs on AT

Training Tips1. For healthy runners:

a) Keep BW% (85-95%) and speeds high to normalize motor patterns (most sport specific)

b) Supplement land running with HIIT or faster paced intervals/tempo runs on AT

2. For injured runners:a) Start at 50-65%BW (determine what is acceptable, ie no pain)b) Stay there for ~ 1 week (minimum)c) Increase 5-10%BW increments weeklyd) No pain during or after runninge) Move to land running after comfortable at 90-95%BW

Training Tips1. For healthy runners:

a) Keep BW% (85-95%) and speeds high to normalize motor patterns (most sport specific)

b) Supplement land running with HIIT or faster paced intervals/tempo runs on AT

2. For injured runners:a) Start at 50-65%BW (determine what is acceptable, ie no pain)b) Stay there for ~ 1 week (minimum)c) Increase 5-10%BW increments weeklyd) No pain during or after runninge) Move to land running after comfortable at 90-95%BW

3. Land based training can be transferred to ATT (unlike DWR)

Training Tips1. For healthy runners:

a) Keep BW% (85-95%) and speeds high to normalize motor patterns (most sport specific)

b) Supplement land running with HIIT or faster paced intervals/tempo runs on AT

2. For injured runners:a) Start at 50-65%BW (determine what is acceptable, ie no pain)b) Stay there for ~ 1 week (minimum)c) Increase 5-10%BW increments weeklyd) No pain during or after runninge) Move to land running after comfortable at 90-95%BW

3. Land based training can be transferred to ATT (unlike DWR)4. Consider using a metronome to focus on cadence

ATT Summary:Necessary future research

1. What are the long term effects of training at a higher speed and lower weight?

2. The relationship btwn BW reduction and GRF’s remains to be better defined.

3. What is the ideal amount of weight support to rehab various diagnoses (stress fractures, post-op achilles tendon surgeries, etc)?

4. How quickly can one advance their weight support?5. For injury prevention, what are ideal parameters of

weight support and speed for a predetermined metabolic workload (but to keep vGRF’s down)?

6. Optimal training methods? (HIIT/supramaximal speeds?)

Thank you