Search Results

You are looking at 241 - 250 of 2,114 items for :

Clear All
Restricted access

Thimo Wiewelhove, Christian Raeder, Tim Meyer, Michael Kellmann, Mark Pfeiffer and Alexander Ferrauti

Purpose:

To investigate the effect of repeated use of active recovery during a 4-d shock microcycle with 7 high-intensity interval-training (HIT) sessions on markers of fatigue.

Methods:

Eight elite male junior tennis players (age 15.1 ± 1.4 y) with an international ranking between 59 and 907 (International Tennis Federation) participated in this study. After each training session, they completed 15 min of either moderate jogging (active recovery [ACT]) or passive recovery (PAS) with a crossover design, which was interrupted by a 4-mo washout period. Countermovement-jump (CMJ) height, serum concentration of creatine kinase (CK), delayed-onset muscle soreness (DOMS), and perceived recovery and stress (Short Recovery and Stress Scale) were measured 24 h before and 24 h after the training program.

Results:

The HIT shock microcycle induced a large decrease in CMJ performance (ACT: effect size [ES] = –1.39, P < .05; PAS: ES = –1.42, P < .05) and perceived recovery (ACT: ES = –1.79, P < .05; PAS: ES = –2.39, P < .05), as well as a moderate to large increase in CK levels (ACT: ES = 0.76, P > .05; PAS: ES = 0.81, P >.05), DOMS (ACT: ES = 2.02, P < .05; PAS: ES = 2.17, P < .05), and perceived stress (ACT: ES = 1.98, P < .05; PAS: ES = 3.06, P < .05), compared with the values before the intervention. However, no significant recovery intervention × time interactions or meaningful differences in changes were noted in any of the markers between ACT and PAS.

Conclusions:

Repeated use of individualized ACT, consisting of 15 min of moderate jogging, after finishing each training session during an HIT shock microcycle did not affect exercise-induced fatigue.

Restricted access

Carrie Plaskett, Peter M. Tiidus and Lori Livingston

Ten volunteers (19-23 years old) performed 9 sets of 12 bilateral knee-extension exercises at 60% 1RM. Following exercise, 4 ultrasound treatments (5-cm transducer head, 1.0-MHz frequency, pulsed mode at 1.0 W/cm2) were applied for 8 min daily to the quadriceps muscle of a randomly selected treatment leg. The placebo leg received similar treatment with the ultrasound apparatus turned off. Knee-extension peak torque values and delayed onset muscle soreness (DOMS) were assessed on each leg prior to exercise and at 20 min and 24, 48, 72, and 96 hr postexercise. Postexercise peak torques declined to 60-70% of preexercise values and returned to normal by 96 hr. DOMS sensation peaked 24 hr postexercise and diminished thereafter. No significant differences in peak torque or DOMS were noted between ultrasound- or placebo-treated legs at any time postexercise. Hence ultrasound, as applied in this study, does not appear to be effective in enhancing postexercise muscle strength recovery or in diminishing DOMS.

Restricted access

Avery D. Faigenbaum, James E. McFarland, Neil A. Kelly, Nicholas A. Ratamess, Jie Kang and Jay R. Hoffman

The purpose of this study was to examine the influence of recovery time following a dynamic warm-up (DY) and a static stretch warm-up (SS) on power performance in adolescent athletes. Following baseline measures, 19 males (16.5 ± 1.1 yrs) performed the vertical jump (VJ) and seated medicine ball toss (MB) at the following time points after DY and SS: 2, 6, 10, 14, 18, 22 min. Analysis of variance revealed that VJ was significantly greater following DY than SS at 2, 6, 10, 14 and 18 min. Main effects indicated a significant increase in VJ from baseline at 2 and 6 min following DY (2.6–3.9%) and a significant decrease in VJ from baseline at 2, 6, 10, 14 and 18 min following SS (–3.2% to –7.0%). No significant interaction effects between DY and SS were observed for MB. These findings indicate that lower body power performance in male adolescent athletes can be enhanced following DY as compared with SS during the first 18 min of the post warm-up period.

Restricted access

Jose Morales, Emerson Franchini, Xavier Garcia-Massó, Mónica Solana-Tramunt, Bernat Buscà and Luis-Millán González

Purpose:

To adapt the work endurance recovery (WER) method based on randori maximal time to exhaustion (RMTE) for combat situations in judo.

Methods:

Eleven international-standard judo athletes (7 men and 4 women; mean age 20.73 ± 2.49 y, height 1.72 ± 0.11 m, body mass 67.36 ± 10.67 kg) were recruited to take part in the study. All participants performed a maximal incremental test (MIT), a Wingate test (WIN), a Special Judo Fitness Test (SJFT), and 2 RMTE tests. They then took part in a session at an international training camp in Barcelona, Spain, in which 4 methods of load quantification were implemented: the WER method, the Stagno method, the Lucia method, and the session rating of perceived exertion (RPEsession).

Results:

RMTE demonstrated a very high test–retest reliability (intraclass correlation coefficient = .91), and correlations of the performance tests ranged from moderate to high: RMTE and MIT (r = .66), RMTE and WIN variables (r = .38–.53), RMTE and SJFT variables (r = .74–.77). The correlation between the WER method, which considers time to exhaustion, and the other systems for quantifying training load was high: WER and RPEsession (r = .87), WER and Stagno (r = .77), WER and Lucia (r = .73). A comparative repeated-measures analysis of variance of the normalized values of the quantification did not yield statistically significant differences.

Conclusions:

The WER method using RMTE is highly adaptable to quantify randori judo sessions and enables one to plan a priori individualized training loads.

Restricted access

Jennifer K. Coffeng, Esther M. van Sluijs, Ingrid J.M. Hendriksen, Willem van Mechelen and Cécile R.L. Boot

Background:

Research is needed to better understand the associations between during-work and after-work-hours physical activity and relaxation and need for recovery (NFR), so a study of these variables in office workers at a financial service provider was undertaken.

Methods:

Self-reported baseline data of 412 employees (mean age = 41.3 y; 39.6% women) were used. Linear regression analyses were performed to test associations of physical activity, relaxation, detachment, and breaks at work with NFR.

Results:

A lower NFR was significantly positively associated with standing, stair climbing, active lunch break, relaxation at work, detachment at work, physical detachment at work, relaxation at home, and detachment at home. In the multiple model, a lower NFR was independently positively associated with frequency of stair climbing, minutes spent in leisure activities, detachment at work, physical detachment at work, and relaxation and detachment at home (P < .05). Significant effect modification indicated that the positive association between relaxation at home and NFR was stronger with high job demands.

Conclusion:

Although prospective evidence is necessary to confirm the causal relationships, our findings suggest that engaging in stair climbing, leisure activities, (physical) detachment at work, relaxation and detachment after work is associated with a lower NFR. For future work site health promotion initiatives, interventions might be targeted at improving physical activity and relaxation.

Restricted access

Vassilis Vardaxis and T. Blaine Hoshizaki

This paper describes and interprets joint and segmental power patterns as functional characteristics of the leg movement in terms of generation, absorption, and transfer of power during the recovery phase of the sprinting stride. In addition, a comparison of the power patterns between advanced and intermediate sprinters was undertaken. Two advanced and two intermediate sprinters, each executing six trials of a 100-m dash, served as subjects. The results revealed that the power patterns for both the advanced and intermediate sprinters were similar in shape, depicting the same number of power phases. The hip joint musculature acted primarily as a power generator in comparison to the knee muscles, which acted mainly as absorbers (controllers) during the recovery phase of the sprinting stride. Differences between ability levels were identified using peak power values, with the advanced sprinters producing higher peak powers earlier in the recovery phase.

Restricted access

Sander P.M. Ganzevles, Arnold de Haan, Peter J. Beek, Hein A.M. Daanen and Martin J. Truijens

For training to be optimal, daily training load has to be adapted to the momentary status of the individual athlete, which is often difficult to establish. Therefore, the current study investigated the predictive value of heart-rate recovery (HRR) during a standardized warm-up for training load. Training load was quantified by the variation in heart rate during standardized training in competitive swimmers. Eight female and 5 male Dutch national-level swimmers participated in the study. They all performed 3 sessions consisting of a 300-m warm-up test and a 10 × 100-m training protocol. Both protocols were swum in front crawl at individually standardized velocities derived from an incremental step test. Velocity was related to 75% and 85% heart-rate reserve (% HRres) for the warm-up and training, respectively. Relative HRR during the first 60 s after the warm-up (HRRw-up) and differences between the actual and intended heart rate for the warm-up and the training (ΔHRw-up and ΔHRtr) were determined. No significant relationship between HRRw-up and ΔHRtr was found (F 1,37 = 2.96, P = .09, R 2 = .07, SEE = 4.65). There was considerable daily variation in ΔHRtr at a given swimming velocity (73–93% HRres). ΔHRw-up and ΔHRtr were clearly related (F 1,37 = 74.31, P < .001, R 2 = .67, SEE = 2.78). HRR after a standardized warm-up does not predict heart rate during a directly subsequent and standardized training session. Instead, heart rate during the warm-up protocol seems a promising alternative for coaches to make daily individual-specific adjustments to training programs.

Restricted access

Yann Le Meur, Martin Buchheit, Anaël Aubry, Aaron J Coutts and Christophe Hausswirth

Purpose:

Faster heart-rate recovery (HRR) after high to maximal exercise (≥90% of maximal heart rate) has been reported in athletes suspected of functional overreaching (f-OR). This study investigated whether this response would also occur at lower exercise intensity.

Methods:

Responses of HRR and rating of perceived exertion (RPE) were compared during an incremental intermittent running protocol to exhaustion in 20 experienced male triathletes (8 control subjects and 13 overload subjects led to f-OR) before and immediately after an overload training period and after a 1-wk taper.

Results:

Both groups demonstrated an increase in HRR values immediately after the training period, but this change was very likely to almost certainly larger in the f-OR group at all running intensities (large to very large differences, eg, +16 ± 7 vs +3 ± 5 beats/min, in the f-OR and control groups at 11 km/h, respectively). The highest between-groups differences in changes in HRR were reported at 11 km/h (13 ± 4 beats/min) and 12 km/h (10 ± 6 beats/min). A concomitant increase in RPE at all intensities was reported only in the f-OR group (large to extremely large differences, +2.1 ± 1.5 to +0.7 ± 1.5 arbitrary units).

Conclusion:

These findings confirm that faster HRR does not systematically predict better physical performance. However, when interpreted in the context of the athletes’ fatigue state and training phase, HRR after submaximal exercise may be more discriminant than HRR measures taken after maximal exercise for monitoring f-OR. These findings may be applied in practice by regularly assessing HRR after submaximal exercise (ie, warm-up) for monitoring endurance athletes’ responses to training.

Restricted access

Peter Peeling, Brian Dawson, Carmel Goodman, Grant Landers, Erwin T. Wiegerinck, Dorine W. Swinkels and Debbie Trinder

Urinary hepcidin, inflammation, and iron metabolism were examined during the 24 hr after exercise. Eight moderately trained athletes (6 men, 2 women) completed a 60-min running trial (15-min warm-up at 75–80% HRpeak + 45 min at 85–90% HRpeak) and a 60-min trial of seated rest in a randomized, crossover design. Venous blood and urine samples were collected pretrial, immediately posttrial, and at 3, 6, and 24 hr posttrial. Samples were analyzed for interleukin-6 (IL-6), C-reactive protein (CRP), serum iron, serum ferritin, and urinary hepcidin. The immediate postrun levels of IL-6 and 24-hr postrun levels of CRP were significantly increased from baseline (6.9 and 2.6 times greater, respectively) and when compared with the rest trial (p ≤ .05). Hepcidin levels in the run trial after 3, 6, and 24 hr of recovery were significantly greater (1.7–3.1 times) than the pre- and immediate postrun levels (p ≤ .05). This outcome was consistent in all participants, despite marked variation in the magnitude of rise. In addition, the 3-hr postrun levels of hepcidin were significantly greater than at 3 hr in the rest trial (3.0 times greater, p ≤ .05). Hepcidin levels continued to increase at 6 hr postrun but failed to significantly differ from the rest trial (p = .071), possibly because of diurnal influence. Finally, serum iron levels were significantly increased immediately postrun (1.3 times, p ≤ .05). The authors concluded that high-intensity exercise was responsible for a significant increase in hepcidin levels subsequent to a significant increase in IL-6 and serum iron.

Restricted access

Jessica M. Stephens, Ken Sharpe, Christopher Gore, Joanna Miller, Gary J. Slater, Nathan Versey, Jeremiah Peiffer, Rob Duffield, Geoffrey M. Minett, David Crampton, Alan Dunne, Christopher D. Askew and Shona L. Halson

Cold-water immersion (CWI) is a widely practiced recovery modality aiming to reduce fatigue and facilitate postexercise recovery. 1 It is thought that the combination of cold temperature and hydrostatic pressure promotes reductions in tissue temperatures and blood flow, facilitating subsequent