Search Results

You are looking at 1 - 9 of 9 items for

  • Author: Ian Jones x
  • Refine by Access: All Content x
Clear All Modify Search
Restricted access

Influence of Fulcrum Position on Springboard Response and Takeoff Performance in the Running Approach

Ian C. Jones and Doris L. Miller

The running forward springboard approaches of 20 divers on the U.S. senior national diving team were analyzed using planar video analysis and accelerometer output; the purpose was to investigate kinematic responses of the springboard tip and divers' lower extremities to alterations in fulcrum setting. Divers executed jump takeoffs from a 1-m springboard with the fulcrum at their preferred setting as well as 0.144 m (two fulcrum numbers) forward and 0.144 m back from that location. Potential advantages of setting the fulcrum back further from the tip (as opposed to closer) included greater downward board tip vertical velocity at the beginning of takeoff, more time to generate angular momentum, and increased vertical velocity going into flight. However, setting the fulcrum further back required the diver to achieve longer hurdle flight durations and to reverse downward motion from a more flexed knee position. Accelerometer output in the absence of video was not beneficial as a means of providing immediate performance feedback for coaching purposes.

Restricted access

Developing Communication and Organization Skills: The ELITE Life Skills Reflective Practice Intervention

Martin Ian Jones, David Lavallee, and David Tod

The aim of the current study was to evaluate the ELITE intervention as a method of increasing the perceived use of communication and organization skills in young people. The participants were three male field hockey players and two female tennis players from a British university. We used a series of single subject, multiple baselines, with minimal meaningful harm and benefit criteria and SMDall effect sizes to evaluate the ELITE intervention. The results revealed no meaningful harm from participating in the program, and the tennis players showed meaningful benefits. SMDall effect sizes all demonstrated that the intervention had a positive effect. Post intervention interviews indicated that participants valued the targeted life skills, and the program was enjoyable. Implications of this study suggest that scholars and practitioners can use the ELITE intervention to increase life skills in young people.

Restricted access

Compression Garments: No Enhancement of High-Intensity Exercise in Hot Radiant Conditions

Martin J. Barwood, Jo Corbett, John Feeney, Paul Hannaford, Dan Henderson, Ian Jones, and Jade Kirke

Purpose:

To establish the thermal and performance effects of wearing a lower-body graduated compression garment (GCG) in a hot environment (35.2°C ± 0.1°C) with a representative radiant heat load (~800 W/m2) in contrast to a control (running shorts) and sham condition (a compression garment 1 size larger than that recommended by the manufacturer), with the latter included to establish any placebo effect.

Method:

Eight participants (mean ± SD; age 21 ± 2 y, height 1.77 ± 0.06 m, mass 72.8 ± 7.1 kg, surface area, 1.89 ± 0.10 m2) completed 3 treadmill tests at a fixed speed for 15 min followed by a self-paced 5-km time trial. Performance (completion time) and pacing (split time), thermal responses (aural, skin, and mean body temperature, cardiac frequency), and perceptual responses (rating of perceived exertion [RPE], thermal sensation, thermal comfort) were measured.

Results:

Performance in the compression group was not different than in either sham or control at any stage (P > .05); completion time 26.08 ± 4.08, 26.05 ± 3.27, and 25.18 ± 3.15 min, respectively. At the end of the 5-km time trial, RPE was not different; it was 19 ± 1 across conditions. In general, thermal and perceptual responses were not different, although the radiant heat load increased site-specific skin temperature (quadriceps) in the garment conditions.

Conclusion:

GCG did not enhance performance in a hot environment with a representative radiant heat load. The sham treatment did not benefit perception. GCG provided no evidence of performance enhancement.

Restricted access

Kinetic and Kinematic Characteristics of 10-m Platform Performances of Elite Divers: I. Back Takeoffs

Doris I. Miller, Ewald Hennig, Marc A. Pizzimenti, Ian C. Jones, and Richard C. Nelson

Reaction forces elicited from the 10-m platform by the 29 male and 26 female competitors in the Fifth World Diving Championships during the takeoffs for dives from the back group were analyzed and related to their patterns of motion. Major changes in linear and angular momentum occurred during the final period of upward acceleration. During this “final weighting” phase, maximum vertical reactions of 3.0 to 4.0 times body weight (BW) and maximum horizontal reactions in the “propulsive” direction of 0.5 BW were recorded. Further, the moment of vertical platform reaction with respect to the center of gravity, which was dominant and promoted backward rotation, was opposed by the moment of the horizontal component. At final contact with the platform, higher vertical velocities were more evident for back dives than multiple back somersaults, and for dives performed in tuck than in pike, and in pike than in straight positions.

Restricted access

Kinetic and Kinematic Characteristics of 10-m Platform Performances of Elite Divers: II—Reverse Takeoffs

Doris I. Miller, Ian C. Jones, Marc A. Pizzimenti, Ewald Hennig, and Richard C. Nelson

Takeoffs for 10-m platform dives from the reverse group at the 1986 World Championships and 1989 FINA Cup were analyzed to provide insights into their kinetic and kinematic characteristics. As with back takeoffs, the major changes in both linear and angular momentum occurred during final weighting (i.e., upward acceleration). Vertical velocities at last contact were higher for reverse dives than reverse multiple somersaults, and different moment-of-force patterns were associated with increased rotational requirements. Last-contact vertical velocities were less for reverse rotating dives than corresponding dives from the back group. Although last-contact horizontal velocities for the two groups were not statistically different, the horizontal acceleration patterns of the three composite body segments were near mirror images of one another. Finally, implications of a resultant head velocity of 10 m/s when passing the leading edge of the platform in reverse multiple somersaulting dives were considered.

Restricted access

Promotion of Healthy Aging Within a Community Center Through Behavior Change: Health and Fitness Findings From the AgeWell Pilot Randomized Controlled Trial

Jeanette M. Thom, Sharon M. Nelis, Jennifer K. Cooney, John V. Hindle, Ian R. Jones, and Linda Clare

The purpose of this randomized controlled trial was to determine if behavior change through individual goal setting (GS) could promote healthy aging, including health and fitness benefits in older adults who attended a community “AgeWell” Center for 12 months. Seventy-five older adults were randomly allocated to either a control or a GS group. Health outcomes were measured at baseline and after 12 months of the participants’ having access to the exception of Agewell Center facilities. The findings demonstrate that participation in the Center in itself was beneficial, with improved body composition and reduced cardiovascular risk in both groups (p < .05), and that this kind of community-based resource offers valuable potential for promoting protective behaviors and reducing health risk. However, a specific focus on identifying individual behavior change goals was required in order to achieve increased activity engagement (p < .05) and to bring about more substantial improvements in a range of health, diet, and physical function measures (p < .05).

Restricted access

Signaling Responses After Varying Sequencing of Strength and Endurance Training in a Fed State

Thomas W. Jones, Ian H. Walshe, David L. Hamilton, Glyn Howatson, Mark Russell, Oliver J. Price, Alan St Clair Gibson, and Duncan N. French

Purpose:

To compare anabolic signaling responses to differing sequences of concurrent strength and endurance training in a fed state.

Methods:

Eighteen resistance-trained men were randomly assigned to the following experimental conditions: strength training (ST), strength followed by endurance training (ST-END), or endurance followed by strength training (END-ST). Muscle tissue samples were taken from the vastus lateralis before each exercise protocol, on cessation of exercise, and 1 h after cessation of strength training. Tissue was analyzed for total and phosphorylated (p-) signaling proteins linked to the mTOR and AMPK networks.

Results:

Strength-training performance was similar between ST, ST-END, and END-ST. p-S6k1 was elevated from baseline 1 h posttraining in ST and ST-END (both P < .05). p-4E-BP1 was significantly lower than baseline post-ST (P = .01), whereas at 1 h postexercise in the ST-END condition p-4E-BP1 was significantly greater than postexercise (P = .04). p-ACC was elevated from baseline both postexercise and 1 h postexercise (both P < .05) in the END-ST condition. AMPK, mTOR, p38, PKB, and eEF2 responded similarly to ST, ST-END, and END-ST. Signaling responses to ST, ST-END, and END were largely similar. As such it cannot be ascertained which sequence of concurrent strength and endurance training is most favorable in promoting anabolic signaling.

Conclusions:

In the case of the current study an acute bout of concurrent training of differing sequences elicited similar responses of the AMPK and mTOR networks.

Restricted access

Countermovement Jump and Isometric Strength Test–Retest Reliability in English Premier League Academy Football Players

Matthew Springham, Nav Singh, Perry Stewart, Jordan Matthews, Ian Jones, Charlie Norton-Sherwood, Dominic May, Jamie Salter, Anthony J. Strudwick, and Joseph W. Shaw

Purpose: To examine the test–retest reliability of countermovement jump (CMJ) and isometric strength testing measures in elite-level under-18 and under-23 academy football players. Methods: A total of 36 players performed 3 maximal CMJs and isometric abductor (IABS), adductor (IADS), and posterior chain (IPCS) strength tests on 2 separate test days using dual force plates (CMJ and IPCS) and a portable strength testing device (IABS and IADS). Relative (intraclass correlation coefficient) and absolute (coefficient of variation, standard error of the measurement, and minimal detectable change [MDC%]) reliabilities for 34 CMJ, 10 IABS, 10 IADS, and 11 IPCS measures were analyzed using between-sessions best, mean, and within-session methods. Results: For all methods, relative reliability was good to excellent for all CMJ and all IADS measures and poor to good for all IABS and IPCS measures. Absolute reliability was good (ie, coefficient of variation < 10%) for 27 (best) and 28 (mean) CMJ variables and for 6 (IABS and IADS) and 2 (IPCS) isometric measures. Commonly used CMJ measures (jump height, eccentric duration, and flight-time:contraction-time ratio) had good to excellent relative reliability and an MDC% range of 14.6% to 23.7%. Likewise, commonly used isometric peak force measures for IABS, IADS, and IPCS had good to excellent relative reliability and an MDC% range of 22.2% to 26.4%. Conclusions: Commonly used CMJ and isometric strength measures had good test–retest reliability but might be limited by their MDC%. Rate-of-force-development measures (for all isometric tests) and impulse measures (IPCS) are limited by poor relative and absolute reliability and high MDC%. MDC% statistics should be considered in the context of typical responsiveness.

Restricted access

The Relationship Between Preoperative Physical Activity With American Society of Anesthesiologists Score and Postoperative Length of Stay in Patients Undergoing Radical Prostatectomy

Efthymios Papadopoulos, Priya Brahmbhatt, Shabbir M.H. Alibhai, George A. Tomlinson, Andrew G. Matthew, Michael Nesbitt, Jennifer M. Jones, Ian Randall, Daniel Sellers, Antonio Finelli, Neil Fleshner, and Daniel Santa Mina

Background: The relationship between preoperative physical activity (PA) and hospital length of stay (LOS) following radical prostatectomy (RP) is poorly understood. In addition, the relationship between PA and the American Society of Anesthesiologists Physical Status score (ASA PS), an established prognosticator of surgical risk, has not been studied. The authors assessed the relationship between leisure-time PA (LTPA), ASA PS, and LOS in individuals undergoing RP. Methods: This retrospective cohort study was conducted using data from an institutional database. Ordinal logistic regression was used to assess the relationship between preoperative LTPA and physical status as indicated by the ASA PS. Binary logistic regression was used to assess the relationship between preoperative LTPA and LOS. Results: A sample of 1064 participants were included in the analyses. The participants in the highest preoperative LTPA quartile had 45% reduced odds (P = .015) of a worse ASA PS classification compared with participants in the lowest quartile. The participants engaging in vigorous LTPA preoperatively had 35% lower odds (P = .014) of a >2-day LOS following RP compared with participants who were not engaging in preoperative vigorous LTPA. Conclusions: Our findings suggest that total and vigorous preoperative LTPA is associated with improved preoperative American Society of Anesthesiologists scores and LOS following RP, respectively.