Peer-Reviewed Scientific Publications

SPEED & AGILITY

ACUTE STUDY: CHANGES IN SPRINT KINEMATICS AND KINETICS WITH UPPER BODY LOADING AND LOWER BODY LOADING USING EXOGEN® EXOSKELETONS

Simperingham and Cronin (9)

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Purpose Statement:

To compare the effects of different WR placements on maximal sprinting performance using a non-motorised treadmill.

Introduction:

WR of 5% BM was attached to either the upper and lower body (Figure 11). Eight sport science students performed four sets of two 6 second sprints on a non-motorised treadmill.

Figure 11: Lower and upper body WR
Key Findings:
  1. For the same relative load (5% BM), greater changes with lower body WR were found compared to upper:
    1. the time to cover distances above 10 m and the peak velocities achieved during AP and MVP were significantly slower by -2.3 to -4.2 % with lower WR
    2. lower WR resulted in a – 2.9 % reduction in step frequency during acceleration
  2. Lower body WR loading resulted in increased vertical GRF (up to 5%), while altering peak velocity, contact time and step frequency (< 5 %).
  3. Upper body WR did not alter velocity but reduced FT up to 15% and consequently decreased vertical GRF relative to BM (up to 6 %).
  4. 7 out of 8 participants perceived improved unloaded sprint performance following four sprints with WR.
Practical Applications:
  1. Lower body loading rather than upper body loading at 5% BM appears to provide a more effective vertical stimulus to increase eccentric strength and muscle stiffness.
  2. For athletes wanting to overload the start and acceleration phase of a sprint, lower body loading may be used to increase GRF and step variables.
  3. A series of sprints with WR may be an effective pre-conditioning stimulus to induce a perception of potentiated unloaded sprint acceleration performance.
ACUTE STUDY: ACUTE CHANGES IN SPRINT RUNNING PERFORMANCE FOLLOWING BALLISTIC EXERCISE WITH ADDED LOWER BODY LOADING

Simperingham, Cronin (10)

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Purpose Statement:

To compare the effects of different WR magnitudes during loaded warm-ups on over ground sprint performance.

Introduction:

WR of 1, 3 and 5% BM was attached to the lower body to assess the effects of different loaded warm-ups on sprinting (Figure 12). One male athlete performed three unloaded 40 m over the ground sprints following different ballistic warm-up methods with WR. Each condition was performed on a separate day.

Figure 12: Thigh and shank WR
Key Findings:
  1. The loaded accelerations and loaded warm-up resulted in longer contact time (3-4%) during initial acceleration, enabling more time for horizontal force application, lower step frequency (-1 to -3%) during acceleration and a substantial acute improvement in sprint performance.
  2. Overloading the vertical force pattern with drop jumps and the more upright flying sprints did not result in a change in sprint acceleration performance.
Practical Applications:

Lower body WR 3% BM worn during a dynamic speed warm-up 40 m accelerations appears to be effective at acutely improving subsequent unloaded sprint at 10, 30 and 40 m performance, perhaps by providing a non-verbal cue for improved lower limb sprint mechanics.

ACUTE STUDY: CHANGES IN ACCELERATION PHASE SPRINT BIOMECHANICS WITH LOWER BODY WEARABLE RESISTANCE

Simperingham, Cronin (11)

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Purpose Statement:

How do different WR loads of the whole leg effect 20 m sprint performance.

Introduction:

Fifteen male amateur rugby players performed three 20 m over the ground sprints with either WR of 3% or 5% BM whole leg loading.

Key Findings:
  1. No significant changes in sprint times over 10 m with either load but the 20 m sprint time with 5% loading was significantly slower than unloaded (-2%) and 3% condition (-1%).
  2. Significant decrease in theoretical maximum velocity (V0) (-5 to -6%) with both loads and non-significant increase in theoretical horizontal force production (F0) (4%) but only with 3% BM.
  3. Theoretical maximum horizontal power output (Pmax) increased with 3% BM (1.2%, p > 0.05) compared to unloaded, though 5%BM WR was significantly decreased (-4.2%) compared to the 3%BM condition.
  4. Significant changes to contact time (4.3-4.5%) and step frequency (-1.7-2.6%). No significant changes to step length or flight time.
Practical Applications:
  1. 3% BM WR serves to increase horizontal force output during the acceleration phase of sprinting and may be suitable for athletes seeking to improve horizontal force and power during sprint acceleration.
  2. Athletes can be safely loaded up to 5% BM without substantially altering sprint mechanics.
  3. No change in sprint time at 10m with either load, therefore, >5%BM may be needed to overload the early acceleration phase.

 


ACUTE STUDY: ACUTE KINEMATIC AND KINETIC ADAPTATIONS TO WEARABLE RESISTANCE DURING SPRINT ACCELERATION

Macadam, Simperingham (12)

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Purpose Statement:

How do different WR placement of the whole leg effect 20 m sprint performance.

Introduction:

Nineteen amateur to semi-professional rugby males performed two 20 m over the ground sprints unloaded and with each WR condition: 3% BM either attached to the anterior or posterior surface of the lower body (Figure 13).

Key Findings:
  1. No significant decrease in time over 20 m, but significant decrease in theoretical maximum velocity (V0) (-5.4 to -6.5 %)
  2. Significant decrease in F-v slope (-10 to -11 %) was found, while a non-significant increase in theoretical maximum horizontal force (F0) (4.9-5.2 %) occurred.
  3. Significant increase in contact time (3.0-4.4%), and decrease in vertical stiffness (-6.2% to -12.0%), SF (3.4% to -3.6%). No change in step length or flight time.
  4. No significant difference between anterior or posterior load positions.
Practical Applications:
  1. No difference between anterior or posterior load positions in mechanical loading measures.
  2. 3% BM WR allows individuals to reinforce ideal early acceleration with speed maintained during the initial acceleration phase (20 m).
  3. Sprinting with 3% BM may benefit athletes requiring a more force dominant F-v profile by improving their external horizontal force production.
ACUTE STUDY: FOREARM WEARABLE RESISTANCE EFFECTS ON SPRINT KINEMATICS AND KINETICS

Macadam, Simperingham (13)

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Purpose Statement:

To compare the effects of WR attached to the forearms on over ground sprint performance in semi-professional male athletes.

Introduction:

Twenty-two male amateur youth rugby players performed two 20 m over the ground sprints with and without 2% BM attached to forearms (Figure 14).

Key Findings:
  1. No significant decrease in times to 10 m, but significant decreases between 10-20m (-2%).
  2. A significant decrease was found in V0 (-1.4%) and horizontal power output (-5.8%), while a non-significant decrease in theoretical maximum velocity (-4.2%) occurred.
  3. A significant increase in contact time (6.5%) and step length (2.1%), and significant decrease in step frequency (-4.1%) and flight time (-5.3%) were found.
Practical Applications:
  1. May reinforce ideal early acceleration with speed maintained during the early acceleration phase (10 m).
  2. 2% BM forearm WR provides sufficient overload of arm action during sprinting without unduly affecting sprinting technique (<6% change).
  3. Forearm WR may be suitable to enhance arm drive mechanics.
  4. An increase in moment of inertia on the arm
ACUTE STUDY: EFFECTS OF FOREARM WEARABLE RESISTANCE ON ACCELERATION MECHANICS IN COLLEGIATE TRACK SPRINTERS

Uthoff, Nagahara (14)

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Purpose Statement:

How does forearm loading affect kinetic and kinematic characteristics during sprinting?

Introduction:

Arm action during sprinting has commonly been thought of as a coordinative mechanism to overcome rotation of the pelvis as a result of lower limb rotational movements, as well as a mechanism that functions to assist horizontal and vertical propulsion. Arm action contributes up to 22% of the body’s total kinetic energy during block starts. Limited previous literature found that forearm wearable resistance loads >2%BM are required to significantly overload sprinting performance and associated step variables.

  • Fourteen sub-elite male sprinters completed 30m sprints from block starts with and without 2%BM forearm loading (
  • Analysed 4 phases of acceleration: start (steps 1-4), early acceleration (steps 5-8), mid-acceleration (steps 9-12), late acceleration (steps 13-16)
    • Kinetic Variables: performance, step frequency (SF), step length (SL), contact (CT) and flight (FT) time
    • Kinematic Variables: Mean propulsive force, Net horizontal impulse, propulsive impulse (HPH+), braking impulse, vertical impulse (IMPv)
Figure 15: 2% BM forearm loading distributed between both arms; loads evenly placed in a dove-tailed manner

 

Key Findings:
  1. Sprint performance (times) were not significantly altered (p>0.05; -1.38% to -1.75%)
  2. SL (+4.01%, ES=0.15 to 1.93) and HPH+ (+5.48%, ES=-0.30 to 1.88) significantly increased at the start of the sprint (phase 1)
  3. Although SF (-4.86%, ES=-1.69 to -0.14) was lower, both FT (+7.70%, ES=0.02 to 1.56) and IMPv (+4.12%, ES=0.07 to 1.72) were greater during late acceleration with loading
Practical Applications:
  1. Forearm WR loading (2% BM) is a good method of overloading arm mechanics during sprinting due to negligible impacts on performance and technique
  2. 2% BM forearm loading during the start phase of acceleration from a block may provide a method for overloading horizontal propulsion, by increasing SL without sacrificing SF
  3. Practitioners should avoid using forearm loading during late acceleration, unless an athlete requires a stimulus which enables more vertical lift in order to reposition their limbs, potentially to minimize over-striding.
ACUTE STUDY: FORCE-VELOCITY PROFILE CHANGES WITH FOREARM WEARABLE RESISTANCE DURING STANDING START SPRINTING

Macadam, Mishra (15)

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Purpose Statement:

How does forearm loading affect the horizontal force velocity profile of a collegiate male sprinter?

Introduction:

Arm mechanics function to maximize sprinting performance. A method of measuring sprint performance is achieved via measuring and athlete’s power and acceleration ability, using a force-velocity profiles. Significant changes in the slope of the F-V profile, along with minimal sprint kinematic changes may elude towards wearable resistance being a training to improve horizontal force during early acceleration of sprinting.

  • Fourteen sub-elite male sprinters completed 30m sprints from split-stance starts with and without 2%BM forearm loading (Figure 15)
  • Analysed force velocity profiles including theoretical horizontal velocity (V0), theoretical horizontal force (F0), horizontal power (PMAX), and the slope of the F-V curve (SFV)
Key Findings:
  1. Sprint performance (times) were significantly increased at -10m (+2.7%, ES: 0.54), -20m (+2.1%, ES: 0.57), and -30m (+1.9%, ES: 0.60)
  2. Significantly decreased PMAX was found when loaded (-6.1%, ES: 0.66)
Practical Applications:
  1. Sprinting from a split-stance start with forearm WR may be a method to train sprinting performance over the mid- to late- acceleration phases
  2. Sprinting with forearm WR affects the force component of the F-V profile, thus altering power capability of trained sprinters
  3. Forearm WR may be a potential training method for athletes aiming to enhance force/power adaptations during acceleration, from a standing start
  4. Forearm WR during sprinting may affect different athletes different, thus a good understanding of the specific horizontal F-V requirements of the sport/athlete is important prior to utilizing forearm WR.
ACUTE STUDY: THE EFFECT OF LOWER LIMB WEARABLE RESISTANCE LOCATION ON SPRINT RUNNING STEP KINEMATICS

Feser, Macadam (16)

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Purpose Statement:

How do different WR placement of the leg effect 50 m sprint performance

Introduction:

Fourteen track and field athletes performed two 50 m over the ground sprints with and without 2% BM attached to either the thigh or shank (Figure 16). WR was placed and oriented to the most distal position from joint of rotation.

Figure 16: Thigh and shank WR of 2% BM

 

Key Findings:
  1. Both the thigh and shank WR significantly decreased the maximal velocity achieved (-1.8 to 2%), though 10 m and 50 m sprint times were minimally changed (p > 0.05).
  2. During the acceleration phase, the only significant difference to the unloaded condition was step frequency with shank WR (-2.1%).
  3. During the maximal velocity phase, shank WR significantly changed step frequency (-2.5%), contact time (2.1%), and flight times (3.3%); thigh WR significantly changed step frequency (-1.4%) and contact time (2.9%).
Practical Applications:
  1. As slightly greater changes to step kinematics were found throughout both phases of the sprint distance with shank WR, practitioners may wish to utilize this placement for athletes needing to overload the acceleration and maximal velocity phases.
  2. It appears peripheral loading (2% BM) of the thigh and shank can be used to overload step frequency and contact time but not step length and width.
ACUTE STUDY: ACUTE SPATIOTEMPORAL AND MUSCLE EXCITATION RESPONSES TO WEARABLE LOWER LIMB LOADING DURING MAXIMAL VELOCITY SPRINTING

Hurst, Kilduff (17)

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Purpose Statement:

To quantify the mechanical effects of adding WR to the thigh or shank segments during maximal velocity sprinting.

Introduction:

Eight university level sprinters performed two 40 m sprints under each condition (unloaded, thigh WR of 1.7% BM, shank WR of 0.6% BM).

Key Findings:
  1. There was a possibly small decrease in maximum velocity In both thigh (-1.8%) and shank (-1.4%) conditions, which was associated with a likely small decrease in step frequency (thigh -3.7%, shank -2.3%) and no clear difference in step length (1-1.5%).
  2. There was a likely small increase in contact time with thigh WR (2.5%), and possibly small increases in both flight time (2.8%) and contact time (1.2%) with shank WR.
  3. There were no clear differences in peak muscle excitation (EMG assessment) of the biceps femoris or semitendinosus between conditions.
Practical Applications:
  1. As changes in sprint performance were small, WR may provide a suitable high degree of specificity training method to bridge the gap between phases of a periodised training plan.
  2. As there were no clear differences in biceps femoris or semitendinosus EMG muscle activity between the conditions, WR of this magnitude does not increase the excitation demand placed on the hamstrings.
TRAINING STUDY: THIGH POSITIONED WEARABLE RESISTANCE IMPROVES 40M SPRINT PERFORMANCE: A LONGITUDINAL SINGLE CASE DESIGN STUDY

Macadam, Nuell (18)

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Purpose Statement:

To quantify the mechanical changes that occur following a five-week sprint training program with WR attached to the thighs.

Introduction:

One male former sprinter (32 years, 72.4 kg and 180.2 cm, 10.90 s 100 m time) undertook a five-week intervention with WR of 2% BM attached to the thighs. The athlete completed two to three sprint session per week in a periodised manner with WR.

Figure 17: Changes in sprint kinematics
Key Findings:
  1. Substantially faster times were found at all distances of 10 m (-3.4%), 20 m (-2.5%), 30 m (-2.4%), and 40 m (-2.4%).
  2. Theoretical maximum velocity (1.2%), theoretical measures of horizontal force (7.1%) and maximum power (8.4%) were all substantially increased. Contact times were substantially decreased (-5.5%), while flight times (4.7%) and vertical stiffness (12.9%) were substantially increased
Practical Applications:
  1. WR provides a sprint-specific method for rotational overload and subsequent speed specific adaptation with decreases in sprint times being accompanied by increases of sprint mechanical properties, reductions in contact times and increases in vertical stiffness
  2. WR attached to the thigh enables loads to be applied directly to the body that will stress specific sprint movements under the specific demands of an actual sport and competitive environment, without compromising the speed of motion, range of motion and specific skill.
TRAINING STUDY: THIGH POSITIONED WEARABLE RESISTANCE AFFECTS STEP FREQUENCY, NOT STEP LENGTH DURING 50M SPRINT-RUNNING

Macadam, Nuell (19)

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Purpose Statement:

To determine the acute changes in spatio-temporal, impulse, and vertical stiffness variables when 2% BM was attached distally to the thighs during maximal effort sprinting.

Introduction:

15 Japanese sprinters performed 2 maximal effort, 50m sprints from block starts under 2 different loading conditions (2%BM and unloaded). Sprint times were measured using timing gates at 10m and 50m. Spatio-temporal, impulse, and vertical stiffness variables were determined from 54 in-ground force platforms (1000Hz) [-1.5m to 50.5m].

  • Step duration: foot strike of one leg to foot strike of the opposite leg
  • Contact time: duration of foot contact with the ground
  • Flight time: duration of no foot contact with the ground
  • Step length: distance between ground contact foot placements for two adjacent steps (L and R) in the A-P direction
  • Step Frequency: Inverse of step duration (1/step duration = 1/s)
  • Step Velocity: step length x step frequency
  • Impulse:
  • Vertical Stiffness:
Figure 18: Wearable Resistance of 2% Body Mass Attached to the Distal Aspect of the Thighs
Key Findings:
  1. Thigh WR has a greater effect on step frequency (decreased) than step length, leading to longer contact times.
  2. Thigh WR resulted in 4.8% decrease in net anterior-posterior impulses in steps 5-14 due to an earlier foot-strike, and thus greater braking impulse.
  3. Vertical stiffness was decreased 5.5% between steps 5-14, potentially due to increased flexion at the knee and ankle joints during the support phase (increased contact times).
Practical Applications:
  1. WR provides a sprint-specific method for rotational overload and subsequent speed specific adaptation with decreases in sprint times being accompanied by increases of sprint mechanical properties, reductions in contact times and increases in vertical stiffness
  2. WR may be a training tool to overload net anterior-posterior impulses, resulting in positive adaptations to horizontal force production, to overcome the additional loading. (Teach the sprinter to increase horizontal force production, and decrease braking of each step)
  3. Thigh WR may provide a training stimulus to overload vertical stiffness, effectively overloading the stretch-shortening cycle, to help reduce leg compliance.
AGILITY EDITORIAL: WEARABLE RESISTANCE TRAINING FOR SPEED AND AGILITY

Cleary Dolcetti, Cronin (21)

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Purpose Statement:

How can wearable resistance be a powerful training modality to improve speed and agility, and how it can be used to first coach and then train athletes.

Introduction:

Most resistance training exercises are vertically orientated, rather than horizontally or laterally which are principle components of speed and agility. Furthermore, traditional resistance training exercise tend to be slower, less range of motion, and acyclic, where movement is typically cyclic in nature. The importance of the principle of specificity in optimizing transference of training adaptation is important for all athletes, more increasingly so for the elite. WR training involves an external load being applied to segments of the body during movement and is an example of one concept of training specificity. WR has the potential to address limiters to transference such as:

  • Lack of velocity
  • Lack of range of motion
  • Contraction type
  • Metabolic specificity to the activity of interest

 

Argument for Wearable resistance:

Mechanical

  • WR allows for other ways of developing high forces, through light loads (grams, kilograms) (Figure 20)
  • WR provides a direct rotational overload to the limb of interest and the associated proximal joints and musculature
  • A change in rotational inertia increases the kinetic output of the joint proximal to the location of the added load, with a greater effect when the load is more distal and when the magnitude is increased.
Figure 20: Different methods for the development of force capability

Neural

  • Improving neural efficiency to enhance force capability and movement quality is key for many S&C coaches
  • Adding load to a sports movement would be a suitable strategy for achieving the specificity needed to develop the necessary intramuscular coordination

Metabolic

  • WR provides a metabolic stimulus during sprinting and agility performance, particularly if the activities are repetitive in nature and more reflective of actual competition-specific demands and durations

 

Tips for Wearable Resistance use:

The use of WR in a periodised plan depends on the requirements of the sport and the individual needs of the athlete. The value of WR as a training tool is during specific strength training; when looking to modify the use of traditional resistance training to find more relevant ways to overload the body that re force, speed, and ROM relevant to the sport.

IndividualisationIf the load feels wrong, change it

  • Loads must be first “felt” and then “lifted” (i.e. if the loading is too heavy, unnatural, or uncomfortably orientation, it should be adjusted)
  • Load adjustments should be both user and coach driven

SpecificityReduce the load not the speed

Progressive OverloadProgress in grams, not kilograms

  • There is an inherent trade-off between load and specificity
  • The load is secondary to the movement
  • Progression can be achieved by moving the same load more distally from the axis of rotation; thus increasing the rotational inertia

OvertrainingListen to your body

  • Although light, WR is still resistance; high velocity movements are generally MORE fatiguing

TEAM SPORTS

EFFECTS OF WARMING UP WITH LOWER-BODY WEARABLE RESISTANCE ON PHYSICAL PERFORMANCE MEASURES IN SOCCER PLAYERS OVER AN 8-WEEK TRAINING CYCLE

Bustos, Metral (25)

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Purpose Statement:

The aim of this study was to quantify the physical performance effects of adding lower-limb wearable resistance to a youth soccer warm-up over 8-weeks

Introduction:

Soccer players spend a considerable amount of time training on-field as well as playing games, forcing strength and conditioning professionals to use time efficient resistance training methods to promote optimal adaptations in congested schedules. Resistance training as a part of what athlete do on the field may provide a specific physiological adaptation to optimize transference directly to their sport, without adverse effects on technique. Further, warm-up programs are designed to prepare the body for specific movements encountered during the sport, and thus performing a warm-up consisting of specific movements with WR affixed to the legs may optimize transfer between training and actual sports movements with minimal effects on technique.

Thirty-one national level U20 Argentinian soccer players (15-18 years, 68.5 ± 5.42kg, 176 ± 0.61cm) were matched for sprinting ability and split into two groups; control group (CON) (n=16) and WR group (n = 15). All participants were tested pre-, mid-, and post- the 8-week training protocol. After a 15-minute standardized warm-up, participants were taken through a testing battery.

Table 5: Performance tests conducted pre-, mid-, and post- 8 week intervention

Speed Repeated Sprint Ability Jump
0 – 10 meters (RSA): 6 x 40 meters

20 meters –> change direction –> 180° –> 20 meters

Bilateral vertical countermovement jump (CMJ)
0 – 20 meters Single leg horizontal jump (SLJ)

 

All subjects performed an 8-week program; WRT group with periodised weight (Table 6). At training sessions, all subjects performed a warm-up protocol consisting of active stretching, technical drills with the ball, and high-intensity accelerations, decelerations, changes of direction, and plyometric and sprint exercises. The WRT group wore compression garments with 200g-600g distributed on each calf (Figure 25) during the warm-up 2-3 times per week.

Table 6: Periodized 8-week loading scheme for the wearable resistance training (WRT) group

Weeks Load-Placement Session 1 Session 2 Session 3
1 200g, posterior, proximal 200g 200g 200g
2 200g, posterior, distal 200g 200g 200g
3 400g, posterior, proximal 400g 400g 400g
4 600g, 400g posterior, proximal 400g Testing 400g
5 400g, posterior, proximal 400g 400g 400g
6 600g, 400g posterior, proximal 600g 600g 600g
7 600g, 400g posterior, distal 600g 600g 600g
8 600g, 400g posterior, proximal 600g 600g 600g

 

Figure 25: Illustration of load placement

 

Key Findings:
  1. The WRT group was found to be more effective (P< 0.05) in reducing 10- and 20-m sprint times for the entire pre-post training cycle than the unloaded CON (ES: -1.06 to -0.96) (60.0% – 66.7% vs. 18.8% – 37.5% > SWC)
  2. No differences between groups for RSA either within groups or between groups for any training block comparison
  3. Both WRT and CON groups improved SLJ performance after the 8-week block (ES = 0.85 and 0.93) (86.7% – 62.5% > SWC), yet no difference in magnitude change were identified over any training blocks
Practical Applications:
  1. Wearable resistance can be used to improve 10m and 20m sprint performance as a part of a warm-up rather than a dedicated sprinting session
  2. Calf loaded WR protocol above provides a movement-specific training stimulus that positively influences sprint ability
  3. In terms of anaerobic adaptations, the accumulated load over 8 weeks of warming up with WR limb loads may be insufficient with resistance less than 600g

WR, when worn during a horizontal ground-based warm-up over 8 weeks, enhances an athletes ability to apply force horizontally, but does not improve vertical jump performance (CMJ)

RUNNING

ACUTE STUDY: EFFECTS OF UPPER AND LOWER BODY WEARABLE RESISTANCE ON SPATIO-TEMPORAL AND KINETIC PARAMETERS DURING RUNNING

Couture, Simperingham (6)

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Purpose Statement:

This study compared the effects of different WR placements on steady state treadmill running performance.

Introduction:

WR of 1-10% BM was attached to either the upper, lower, or whole-body (Figure 1) during treadmill running (3.9 m/s). Twelve recreational trained/ sport science student subjects were randomly assigned to five minutes of treadmill running with each WR condition: 1% BM lower body. 3% BM lower body, 5% BM lower body, 5% BM upper body, 5 % BM whole body, 10% BM whole body.

Key Findings:
  1. 5% BM and greater WR loads caused significant changes in vertical stiffness, vertical and horizontal force, and impulse.
  2. Functional and effective propulsive force (3.0%, 2.8%) and impulse (2.9%, 3.5%) were significantly greater with lower 5% BM than upper 5% BM.
  3. The lower body 5% BM (2.2%) and whole body 10% BM (4.9%) conditions resulted in the lowest relative increase in functional peak vGRF compared to increase in BM (Figure 3).
  4. Only significant spatiotemporal change was to contact time, which increased (2.9%) with whole body 10% BM.
  5. Heart rate was significantly greater with all WR conditions (5.4-8.8%) and RPE significantly greater with lower 5% BM (27.9%) and whole body 10% BM (32.6%).

Practical Applications:
  1. WR may be used to increase forces and muscular stimulus without negatively effecting normal running gait.
  2. A runner with an overly “bouncy” stride (excessive vertical motion), may benefit from lower body WR to increase horizontal force.
  3. A runner with a long, low stride may benefit from upper body WR to increase vertical force and balancing out the trajectory may be more beneficial.
ACUTE STUDY: ACUTE METABOLIC CHANGES WITH THIGH-POSITIONED WEARABLE RESISTANCES DURING SUBMAXIMAL RUNNING IN ENDURANCE-TRAINED RUNNERS

Field, Gill (7)

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Purpose Statement:

Investigate how a magnitude of between 1% and 5% BM WR attached to the thigh affects the acute metabolic responses to submaximal running in endurance trained runners

Introduction:

In recreational distance runners, heavy resistance, explosive resistance and muscle endurance resistance training have been found to significantly improve running performance. At elite levels, concepts of progressive overload and specificity become more important. Twenty endurance-trained runners performed four sessions (Figure 4); familiarization and three testing sessions on a motorized treadmill with different thigh loading schemes (0% [unloaded], 1%, 2%, 3%, 4%, 5%). Metabolic response measures of HR response, oxygen consumption (VO2), lactate accumulation (LA), training load score (TLS)(combination of avgHR, intensity factor, VT2 – point which LA accumulation exceeds clearance), and rate of perceived exertion (RPE).

 

Figure 4: Structure of Testing Sessions

 

 

Key Findings:
  1. There is an expected 1.59% (± 0.62) increase in VO2 for every 1% BM of additional thigh load
  2. There is an expected 0.63% (± 0.32) increase in acute HR for every 1% BM of additional thigh load
  3. Loads at 3% and 4% BM reported very likely large increases in lactate accumulation (0.41 ± 0.18 and 0.42 ± 0.19 respectively) with mean accumulations of 3.27 (±1.79) and 3.30 mmol/L (±2.03) respectively and most likely very large increase at 5% BM (3.52 mmol/L)(Figure 5)
  4. Both 4% and 5% BM reported most likely very large increases in RPE (0.82 ± 0.29 and 0.86 ± 0.28 respectively), with mean reported scores of 4.20 (±1.26) and 4.38 (±1.57) respectively (Figure 5)

 

Figure 5: Lactate Accumulation and Rate of Perceived Exertion (0% – 5% BM)

Practical Applications:
  1. Limb loading during locomotion can increase metabolic cost compared to unloaded
  2. When WR is attached to the thighs, great VO2 changes occur compared to trunk placement, most likely due to greater inertial demands from distal thigh loading
  3. Loads of at least 2% and 3% BM are needed to see substantial increases in HR and VO2
  4. WR attached to the legs enable a running-specific form of resistance training to be incorporated into training programming
ACUTE STUDY: ACUTE METABOLIC CHANGES WITH LOWER LEG-POSITIONED WEARABLE RESISTANCES DURING SUBMAXIMAL RUNNING IN ENDURANCE-TRAINED RUNNERS

Field, Gill (8)

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Purpose Statement:

Investigate how a magnitude of between 0% and 2.55% BM WR attached to the calf affects the acute metabolic responses to submaximal running in endurance trained runners

Introduction:

In recreational distance runners, heavy resistance, explosive resistance and muscle endurance resistance training have been found to significantly improve running performance. At elite levels, concepts of progressive overload and specificity become more important. Twenty endurance-trained runners performed four sessions (Figure 4); familiarization and three testing sessions on a motorized treadmill with different calf loading schemes (0% [unloaded], 0.5%, 1.0%, 1.5%, 2%, 2.5%). Metabolic response measures of HR response, oxygen consumption (VO2), lactate accumulation (LA), training load score (TLS)(combination of avgHR, intensity factor, VT2 – point which LA accumulation exceeds clearance), and rate of perceived exertion (RPE).

 

Figure 6: Structure of Testing Sessions

 

Figure 7: Example of lower-leg wearable resistance loading pattern (0.5%) for a 70kg runner

 

Figure 8: Example of lower-leg wearable resistance loading pattern (1.5%) for a 70kg runner

 

Figure 9: Example of lower-leg wearable resistance loading pattern (2.5%) for a 70kg runner

Key Findings:
  1. There is an expected 2.56% (± 0.75) increase in VO2 for every 1% BM of additional calf load
  2. There is an expected 1.16% (± 0.52) increase in acute HR for every 1% BM of additional calf load
  3. There is an expected 0.39% (± 0.06) increase in exercise stress for the equivalent of 10-min of running for every 1% BM of additional calf load
  4. There were most likely very large increases in both acute lactate accumulation and RPE with 2.5% and greater BM of calf loading

Figure 10: Lactate Accumulation and Rate of Perceived Exertion (0% – 5% BM)

 

Practical Applications:
  1. Limb loading during locomotion can increase metabolic cost compared to unloaded
  2. When WR is attached to the thighs, great VO2 changes occur compared to trunk placement, most likely due to greater inertial demands from distal thigh loading
  3. Loads of at least 2% and 3% BM are needed to see substantial increases in HR and VO2
  4. WR attached to the legs enable a running-specific form of resistance training to be incorporated into training programming

GOLF

ACUTE STUDY: WEARABLE RESISTANCE ACUTELY ENHANCES CLUB HEAD SPEED IN FEMALE SKILLED GOLFERS

Paul Macadam, Anita Chau, John Cronin

Link to Publication

Purpose Statement:

To investigate the effects of WR on golf swing performance in highly skilled female golfers.

Introduction:

WR of ~3% BM was attached laterally to the posterior of the upper and lower body (Figure 23) on five highly skilled female golfers. Each subject performed 10 shots unloaded and 10 shots with WR in a randomised order.

 

Figure 23: Lateral and posteriorly loaded upper and lower body WR of ~3% BM

 

 

Key Findings:
  1. Significant acute increases were found in shot distance (7%) and club head speed (3.5%)
  2. Relative vertical GRF (11.4%, lead side), and relative mediolateral GRF (7.1%, trail side) were significantly increased with WR as compared to the unloaded condition.
Practical Applications:
  1. A golf swing specific method to acutely improve golf shot distance, club head speed and GRF.
  2. May be a training tool to increase rotational force and velocity without unduly affecting swing mechanics without the loads attached to the arms.

SWIMMING

THESIS: WEARABLE RESISTANCE TECHNOLOGY TO ENHANCE SWIMMING PERFORMANCE (STUDY 1)

Quirke (20)

Link to Publication

Purpose Statement:

The aims were to determine the acute metabolic effects of variable proximal upper limb loading using WRT during submaximal swimming

Introduction:

The principle of training specificity indicates that added resistance training in swimming will be more effective if applied through the exact stroke mechanism in an aquatic environment. Fifteen (male=7; female=8) national level swimmers completed two sessions, with 24 hrs recovery in between. The first session involved determination of the subjects’ lactate threshold using a 7x200m incremental step test. The second session required each subject to complete 6x200m freestyle swims at individualized submaximal speeds with variable loads ranging from 0g-500g proximally loaded to each arm using WRT. During each swim the subjects were randomly assigned one of six WR loads [0g (control), 100g, 200g, 300g, 400g, 500g] to be proximally loaded to each upper arm compression sleeve (Figure 19). RPE was also collected after each 200m to see if the subjects identified a difference in difficulty between the different WR loads

 

Figure 19: Proximal Upper Arm Loading of Wearable Resistance

 

Key Findings:
  1. There was no substantial difference in swim times for males between any WR loaded trials
  2. There was no increase in RPE in males (mean: 15.4 ± 2.1 RPE)
  3. Males experienced substantially higher BL levels when loads exceeded 300g; females BL levels were unclear
    1. 400g: ↑74 ± 1.32 mmol-1, 0.41, (-0.13 – 0.96)
    2. 500g: ↑40 ± 3.06mmol-1, 1.29, (-0.06-2.63)
  4. There were significantly slower swim speeds with loads over 300g for females
    1. 400g (↑11 ± 2.56sec, 1.9%, (0.8-3.1))
    2. 500g (↑05 ± 2.35sec, 2.6%, (1.4-3.8))
  5. There was a significantly small increase in female RPE over 200g loading trials compared to the control (0g)
    1. 300g (↑2 ± 1.9RPE, 0.53, (-0.19 – 1.25))
    2. 400g (↑1 ± 1.9RPE, 0.58, (-0.11 – 1.27))
    3. 500g trial (↑1 ± 2.3RPE, 0.58, (-0.26 – 1.42))
Practical Applications:
  1. Males and females respond differently to added WR upper arm loads during submaximal swimming
  2. Wearable resistance during swimming may be used to influence the “training zone” of the male athlete, likely by changing the input of each energy system and applying overload to the upper body musculature
  3. Females may not be strong enough to withstand higher loads during swimming and maintain swimming speeds
  4. Upper arm WR loads exceeding 300g may be too high for female swimming athletes
  5. For swimming, gender specific loading and training manipulation is necessary

COMBAT SPORTS

EFFECTS OF A SIX-WEEK STRENGTH AND POWER TRAINING PROGRAM ON PUNCHING AND KICKING IMPACT POWER IN AMATEUR MALE COMBAT ATHLETES: A PILOT STUDY

Vecchio LD1*, Stanton R2,5,6, Campbell Macgregor2,4, Brendan Humphries2 and Nattai Borges

Link to Publication

Purpose Statement:

Examine effect of 6-week EXOGEN® combat program on punching and kicking impact power in amateur male combat athletes.

Introduction:

Seventeen amateur (minimum 2 years of MMA or kickboxing) combat athletes were allocated to either an EXOGEN® (n=10, 28.2 ± 1.7 years, 79.5 ± 7.7kg, 176.6 ± 4.7 cm) or Control (n=7, 29.0 ± 2.0 years, 79.8 ± 11.9kg, 177.7 ± 5.7 cm) group for six weeks. A pre-post study design was used with the following performance tests: Standing vertical jump test, 5RM half-squat, and 5RM bench press. Impact power testing was assessed in the following movements: Lead-hand jab, read-hand cross, rear-leg front kick, and Rear-leg roundhouse kick (using StrikeMate®).

The six-week periodised program consisted of 3 x 60-minute training sessions/week. The EXOGEN® group performed 2 out of 3 sessions with wearable resistance (Table 4). The suit consisted of Lila® EXOGEN® compression-based arm sleeves, pants, and calf sleeves, and loads (2-4.5% BW) located over the midline of the intended appendage. Loads were positioned over the upper and lower lib, lateral hip, anterior thigh, anterior and posterior lower limb (Figure 24).

 

Figure 24: EXOGEN® Load Placement

 

 

Table 4: Six Week EXOGEN Loading Scheme

Key Findings:
  1. A six week EXOGEN® training programme significantly improved jab impact power (p=0.025, ES=0.73, +25.9% change)
  2. A six week EXOGEN® training programme significantly improved rear-hand cross impact power (p=0.004, ES=1.00, +51.2% change)
  3. A significant increase in bench press strength (p=0.008, ES=0.32, +6.0% change) was observed in the EXOGEN® trained group
  4. A significant increase in vertical jump height (p=0.025, ES=1.50, +19.2% change) and 5RM half-squat (p=0.02, ES=0.26, +6.9% change) was observed in the EXOGEN® trained group
  5. Front kicking impact power did not significantly increase in either the EXOGEN® or control group
Practical Applications:
  1. A six week periodised EXOGEN® training programme significantly improves both jab and rear-cross punching impact power in amateur male combat athletes, which may improve an athlete’s change of success in striking martial arts.
  2. Greater loads may need to be used to improve front kick impact power
  3. EXOGEN® training may be beneficial for vertical jump height, half squat, and bench press strength, particularly when combined with plyometric exercise

JUMPING

ACUTE STUDY: ACUTE KINEMATIC AND KINETIC ADAPTATIONS TO WEARABLE RESISTANCE DURING VERTICAL JUMPING

Paul Macadam, Kim D. Simperingham, John B. Cronin, Grace Couture & Chloe Evison

Link to Publication

Purpose Statement:

To compare the effects of different WR placements and magnitudes on vertical jump performance.

Introduction:

WR of 3% or 6% BM, attached to either the upper body and lower body (Figure 1), was used to assess the acute effects on CMJ, DJ and pogo jump performance in recreational trained/ sport science student subjects (10 males and 10 females). Loads were evenly distributed for upper body loading, and for lower body, 2/3rd of the load placed evenly around the thigh and the remaining 1/3rd on the shank of the leg.

Figure 1: Upper and lower body WR

 

 

Key Findings:
  1. Acute significant decreases in jump height (-10% to -17%) were found in CMJ & DJ, due to reduced peak power (-7% to -17%) and peak velocity (-3% to -8%).
  2. No significant effect on landing ground reaction force (GRF) with any condition.
  3. Acute significant increases in contact time (7.9-9.7%) and decreases in flight time (-7.7% to -8.2% with 6% BM only) resulted in significantly decreased reactive strength index (-16.9% to -21.4%) in pogo jumping.
  4. Greater acute decreases found in lower than upper body WR, but no significant difference between conditions.
Practical Applications:
  1. Safely overload athletes up to 6% BM without increasing landing GRF with either upper or lower body WR.
  2. Given stability of force measure and velocity decrement, athletes should focus on velocity of movement to improve power output and jump height i.e. CMJ take-off velocity.
  3. May enhance SSC performance in DJ and PJ due to overload requiring extensor strength to reduce contact time and improve flight time and stiffness.
  4. Improved specificity of training was theorised as WR was proposed to be less likely to alter the jump flight path compared to barbell or dumbbell loading.

WEIGHTLIFTING

ACUTE STUDY: THE EFFECT OF WEARABLE RESISTANCE ON POWER CLEANS IN RECREATIONALLY TRAINED MALES

Marriner, Cronin (22)

Link to Publication

Purpose Statement:

To compare the effects of different WR magnitudes on power clean performance in resistance trained males.

Introduction:

WR of 5% or 12% BM attached to the posterior of the upper and lower body (Figure 21) was used to examine the acute effects on power clean lifting. Nine recreational trained males performed two reps of the power clean (PC) at 50 and 70% 1RM with each WR condition, i.e. power cleans with and without load redistributed from the bar to the body via WR, in a randomized order.

Figure 21: Posteriorly loaded upper and lower body WR of 5% and 12% BM

 

Key Findings:
  1. WR significantly increased acute power output (11.5-16.8%) via increased barbell velocity (3.3-4.7%).
  2. Similar GRF between WR and traditional power clean loading were observed.
  3. Positive acute technique changes for power clean performance with WR (barbell rearward displacement increased by 17.8%).
  4. Greater beneficial changes found with 12% than 5% BM redistribution.
Practical Applications:
  1. Provides a means to acutely increase power clean barbell velocity and power output.
  2. Due to reduced barbell load, enables training for less technically proficient lifters or lifters returning from injury, while minimising injury risk (e.g. wrist mobility limitations).
  3. Enables lifters to focus on technical aspects of the lift (minimising the horizontal displacement of the barbell).
  4. May be suitable for athletes who perform high velocity movements.
TRAINING STUDY: REDISTRIBUTING LOAD USING WEARABLE RESISTANCE DURING POWER CLEAN TRAINING IMPROVES ATHLETIC PERFORMANCE

Marriner, Cronin (5)

Link to Publication

Purpose Statement:

To investigate how power clean training with WR over a 5-week period effects power clean maximum strength performance in resistance trained males.

Introduction:

WR of 12% attached to the posterior of the upper and lower body (Figure 2) was used during a 5-week training study into the effects on power clean lifting. Two groups of eight recreational trained males completed power cleans either with load redistributed from the bar to the body via WR, or via traditional power clean training. Both groups performed two sessions a week in an undulating periodised plan. Technique variables during power clean bar path are shown in Figure 22.

Figure 22: Technique variables during power clean bar path.

(DxL = furthest forward position to catch, DxT = start position to catch, Dx2 = start position to beginning of 2nd pull, DxV = 2nd pull position to forward position CxH = barbell catch height)

 

 

Key Findings:
  1. Significant increase (4.2%) in 1RM power clean in WR group compared to traditional loading.
  2. Barbell velocity increased at 70 and 90% 1RM (ES= 0.16 to 0.74) in the WR group.
  3. Power output increased at 50, 70 and 90% 1RM (ES = 0.33 to 0.62) in the WR group.
  4. Similar GRF between WR and traditional loading.
  5. Positive technique changes for power clean performance with WR at 70 and 90% 1RM (ES = 0.23 to 0.96).
Practical Applications:
  1. Provides a means to chronically increase power clean barbell velocity and power output.
  2. Method to increase 1RM power clean.
  3. Due to reduced barbell load, enables training for less technically proficient lifters or lifters returning from injury, while minimising injury risk (e.g. wrist mobility limitations).
  4. Enables lifters to focus on technical aspects of the lift (minimising the horizontal displacement of the barbell).

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