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Daniel G. Baker and Robert U. Newton

Purpose:

To examine the upper body strength, speed, power, and strength-endurance of rugby-league players of different ranks. These data could provide information pertinent to the importance of these factors for different grades of rugby league and for positional groups in those different grades.

Methods:

Sixty rugby-league players, 20 participants each in the elite, national first-division league (NRL), state-based second-division league (SRL), and intracity third-division league (CRL), served as subjects. Maximal upper body strength, power, speed, and muscle endurance were assessed using the bench-press exercise.

Results:

The NRL players were significantly stronger (141.4 ± 15.4 kg) than SRL (126.6 ± 13.1 kg, ES = 1.033) and CRL (108.1 kg ± 11.6, ES = 2.458) and more powerful (NRL = 680 ± 99 W) than SRL (591 ± 72 W, ES = 1.037) and CRL players (521 ± 71 W, ES = 1.867). The differences in speed (NRL = 345 ± 31 W, SRL = 319 ± 29 W, CRL = 303 ± 29 W; ES = 0.884 and 1.409, respectively) and strength-endurance (NRL = 36 ± 7 reps, SRL = 32 reps ± 7, CRL = 24 ± 5 reps; ES = 0.521 and 1.984, respectively) were not as pronounced.

Conclusions:

Of the tests undertaken, maximal strength best describes players who attain NRL ranking. Maximum power and strength-endurance were also strong descriptors of attainment of NRL level. Upper body speed appears less likely to strongly discriminate between players who attain NRL level and those who do not. These results tended to hold true across the different team positional groupings.

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Ecosse L. Lamoureux, Aron Murphy, Anthony Sparrow, and Robert U. Newton

This study examined the effects of improved strength on an obstacle course (OC) simulating gait tasks commonly encountered by community-living older adults. Forty-five adults (mean age 68.2 ± 1.5 years) were randomly assigned to a control (10 women, 5 men) or an experimental group (EXP; 19 women, 10 men) and trained 3 days/week for 12 weeks. Using a 1-repetition-maximum (1-RM) method, 6 leg-strength measures were evaluated pre- and posttest. The times to walk an OC of 4 gait tasks (stepping over and across an obstacle, negotiating a raised surface, and foot targeting) set at 3 progressively challenging levels were also assessed. Significant Group × Time interactions were found on all 1-RM tests, with only EXP recording significant improvements (124–147%; p < .001). Strength gains in EXP were accompanied by significant improvements in the times to negotiate all gait stations and walk the entire OC (6-15%; p = .001–.014). This study showed that improving strength is an effective strategy to improve community locomotion, which might decrease the risks of falls in community-living older adults.

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Stuart J. Cormack, Robert U. Newton, and Michael R. McGuigan

Purpose:

To examine the acute and short-term responses of variables obtained during a single countermovement jump (CMJ1); repeated countermovement jump involving 5 consecutive efforts without a pause (CMJ5); and cortisol, testosterone, and testos-terone-to-cortisol ratio (T:C) to an elite Australian Rules Football (ARF) match with a view to determining which variables may be most useful for ongoing monitoring.

Methods:

Twenty-two elite ARF players participating in a preseason cup match performed a CMJ1 and a CMJ5 and provided saliva samples 48 h before the match (48pre), prematch (Pre), postmatch, 24 h post (24post), 72 h post (72post), 96 h post (96post), and 120 h post (120post). The magnitude of change in variables at each time point compared with Pre and 48pre was analyzed using the effect size (ES) statistic.

Results:

A substantial decrement in the pre- to postmatch comparison occurred in the ratio of CMJ1 Flight time:Contraction time (ES −0.65 ± 0.28). Cortisol (ES 2.34 ± 1.06) and T:C (ES −0.52 ± 0.42) displayed large pre- to postmatch changes. The response of countermovement variables at 24post and beyond compared with pre-match and 48pre was varied, with only CMJ1 Flight time:Contraction time displaying a substantial decrease (ES −0.32 ± 0.26) postmatch compared with 48pre. Cortisol displayed a clear pattern of response with substantial elevations up to 24post compared with Pre and 48pre.

Conclusion:

CMJ1 Flight time:Contraction time appears to be the most useful variable for monitoring neuromuscular status in elite ARF players due to its substantial change compared with 48pre and prematch. Monitoring cortisol, due to its predictable pattern of response, may provide a useful measure of hormonal status.

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Daniel A. Galvão, Robert U. Newton, and Dennis R. Taaffe

Resistance training has been shown to be the most effective exercise mode to induce anabolic adaptations in older men and women. Advances in imaging techniques and histochemistry have increased the ability to detect such changes, confirming the high level of adaptability that remains in aging skeletal muscle. This brief review presents a summary of the resistance-training studies that directly compare chronic anabolic responses to training in older (>60 years) men and women. Sixteen studies are summarized, most of which indicate similar relative anabolic responses between older men and women after resistance training. Relatively small sample sizes in most of the interventions limited their ability to detect significant sex differences and should be considered when interpreting these studies. Future research should incorporate larger sample sizes with multiple measurement time points for anabolic responses.

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Joseph O.C. Coyne, Robert U. Newton, and G. Gregory Haff

Purpose: A simple and 2 different exponentially weighted moving average methods were used to investigate the relationships between internal training load and elite weightlifting performance. Methods: Training impulse data (sessional ratings of perceived exertion × training duration) were collected from 21 elite weightlifters (age = 26.0 [3.2] y, height = 162.2 [11.3] cm, body mass = 72.2 [23.8] kg, previous 12-mo personal best total 96.3% [2.7%] of world record total) during the 8 weeks prior to the 2016 Olympic Games qualifying competition. The amount of training modified or cancelled due to injury/illness was also collected. The training stress balance (TSB) and acute to chronic workload ratio (ACWR) were calculated with the 3 moving average methods. Along with the amount of modified training, TSB and ACWR across the moving average methods were then examined for their relationship to competitive performance. Results: There were no consistent associations between performance and training load on the day of competition. The volatility (SD) of the ACWR in the last 21 days preceding the competition was moderately correlated with performance across moving average methods (r = −.41 to .48, P = .03–.07). TSB and ACWR volatility in the last 21 days were also significantly lower for successful performers but only as a simple moving average (P = .03 and .03, g = 1.15 and 1.07, respectively). Conclusions: Practitioners should consider restricting change and volatility in an athlete’s TSB or ACWR in the last 21 days prior to a major competition. In addition, a simple moving average seemed to better explain elite weightlifting performance than the exponentially weighted moving averages in this investigation.

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Kieran P. Young, G. Gregory Haff, Robert U. Newton, and Jeremy M. Sheppard

Purpose:

The purpose of this study was to evaluate the reliability of an isometric-bench-press (IBP) test performed across 4 elbow angles and a ballistic bench throw (BBT) using a relative load, as well as evaluating the reliability of the dynamic strength index (DSI: BBT peak force/IBP peak force).

Methods:

Twenty-four elite male athletes performed the IBP and a 45% 1-repetition-maximum BBT on 2 separate days with 48 h between testing occasions. Peak force, peak power, peak velocity, peak displacement, and peak rate of force development (PRFD) were assessed using a force plate and linear position transducer. Reliability was assessed by intraclass correlation (ICC), coefficient of variation (%CV) and typical error.

Results:

Performance measures in the BBT, such as peak force, peak velocity, peak power, and peak displacement, were considered reliable (ICC = .85–.92, %CV = 1.7–3.3), while PRFD was not (ICC = .43, %CV = 4.1). Similarly, for the IBP, peak force across all angles was considered reliable (ICC = .89–.97, %CV = 1.2–1.6), while PRFD was not (ICC = .56–.65, %CV = 0.5–7.6). The DSI was also reliable (ICC = .93, %CV = 3.5).

Conclusions:

Performance measures such as peak force in the IBP and BBT are reliable when assessing upper-body pressing-strength qualities in elite male athletes. Furthermore, the DSI is reliable and could potentially be used to detect qualities of relative deficiency and guide specific training interventions.

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Kieran P. Young, G. Gregory Haff, Robert U. Newton, Tim J. Gabbett, and Jeremy M. Sheppard

Purpose:

To evaluate whether the dynamic strength index (DSI: ballistic peak force/isometric peak force) could be effectively used to guide specific training interventions and detect training-induced changes in maximal and ballistic strength.

Methods:

Twenty-four elite male athletes were assessed in the isometric bench press and a 45% 1-repetition-maximum (1RM) ballistic bench throw using a force plate and linear position transducer. The DSI was calculated using the peak force values obtained during the ballistic bench throw and isometric bench press. Athletes were then allocated into 2 groups as matched pairs based on their DSI and strength in the 1RM bench press. Over the 5 wk of training, athletes performed either high-load (80–100% 1RM) bench press or moderate-load (40–55% 1RM) ballistic bench throws.

Results:

The DSI was sensitive to disparate training methods, with the bench-press group increasing isometric bench-press peak force (P = .035, 91% likely), and the ballistic-bench-throw group increasing bench-throw peak force to a greater extent (P ≤ .001, 83% likely). A significant increase (P ≤ .001, 93% likely) in the DSI was observed for both groups.

Conclusions:

The DSI can be used to guide specific training interventions and can detect training-induced changes in isometric bench-press and ballistic bench-throw peak force over periods as short as 5 wk.

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Stuart J. Cormack, Robert U. Newton, Michael R. McGuigan, and Tim L.A. Doyle

Purpose:

To establish the reliability of various measures obtained during single and repeated countermovement jump (CMJ) performance in an elite athlete population.

Methods:

Two studies, each involving 15 elite Australian Rules Football (ARF) players were conducted where subjects performed two days, separated by one week, of AM and PM trials of either a single (CMJ1) or 5 repeated CMJ (CMJ5). Each trial was conducted on a portable force-plate. The intraday, interday, and overall typical error (TE) and coefficient of variation (CV%) were calculated for numerous variables in each jump type.

Results:

A number of CMJ1 and CMJ5 variables displayed high intraday, interday, and overall reliability. In the CMJ1 condition, mean force (CV 1.08%) was the most reliable variable. In the CMJ5, fight time and relative mean force displayed the highest repeatability with CV of 1.88% and 1.57% respectively. CMJ1Mean force was the only variable with an overall TE < smallest worthwhile change (SWC).

Conclusion:

Selected variables obtained during CMJ1 and CMJ5 performance can be used to assess the impact of both acute and chronic training and competition. Variables derived from the CMJ5 may respond differently than their CMJ1 counterparts and should provide insights into differential mechanisms of response and adaptation.

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Robert U. Newton, William J. Kraemer, Keijo Häkkinen, Brendan J. Humphries, and Aron J. Murphy

The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Performance was significantly higher during the throw movement compared to the press for average velocity, peak velocity, average force, average power, and peak power. Average muscle activity during the concentric phase for pectoralis major, anterior deltoid, triceps brachii, and biceps brachii was higher for the throw condition. It was concluded that performing traditional press movements rapidly with light loads does not create ideal loading conditions for the neuromuscular system with regard to explosive strength production, especially in the final stages of the movement, because ballistic weight loading conditions where the resistance was accelerated throughout the movement resulted in a greater velocity of movement, force output, and EMG activity.

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Michael R.M. McGuigan, Roger Bronks, Robert U. Newton, John C. Graham, and David V. Cody

Peripheral arterial disease (PAD) is associated with impaired lower extremity function. This study investigated differences in PAD and control participants and the relationship between lower limb strength and clinical measures of PAD severity. Participants were evaluated by 6-min-walk distance, normal and maximal walking speed over 10 m, isometric plantar-flexion strength, and dynamic dorsi-/plantar-flexion strength. Hemodynamic measures of the lower limbs were recorded at rest and after maximal treadmill testing. PAD participants walked significantly less far during the 6-min walk, and there were large differences in normal and maximal walking speeds. Small to moderate differences were found for isometric plantar-flexion strength. In the diseased legs of the PAD participants, resting systolic hallux photoplethysmography was significantly correlated with isokinetic plantar-flexion strength and onset of claudication pain during the 6-min-walk test. In addition to confirming the documented loss of walking endurance, these data suggest that loss of strength of the plantar flexors is associated with increasing PAD impairment.