Jose Morales

Use of Heart Rate Variability in Monitoring Stress and Recovery in Judo Athletes

Abstract Morales, J, Álamo, JM, García-Massó, X, Buscà, B, López, JL, Serra-Añó, P, and González, L-M. Use of heart rate variability in monitoring stress and recovery in judo athletes. J Strength Cond Res 28(7): 1896–1905, 2014—The main objective of this study was to examine the effect of different judo training loads on heart rate variability (HRV) measurements, to determine if they can be used as valid indicators in monitoring stress and recovery in judo athletes. Fourteen male national-standard judo athletes were randomly divided into 2 groups, and each group followed a different type of training, namely, a high training load (HTL) and a moderate training load program (MTL). Data collection included HRV measurements, a Recovery Stress Questionnaire for athletes (RESTQ-SPORT), and strength measurements, 4 weeks before and after the training program. The HTL group had lower square root of the mean squared difference of successive RR intervals, very low frequency, high frequency, short-term variability, short-range scaling exponents, general recovery, sport-specific recovery, general stress, maximum strength, maximum power, and higher low/high frequency ratio at posttest compared with pretest (p ⩽ 0.05). The HTL group showed lower short-range and long-range scaling exponents, general recovery, sport-specific recovery, and higher general stress than the MTL group in posttest measurements (p ⩽ 0.05). In conclusion, judo athletes enrolled in an HTL program showed an imbalance of the autonomic nervous system with decreased vagal modulation, together with a decrease in strength parameters, higher markers for stress, and a lower perception of recovery.

ACUTE EFFECTS OF JAW CLENCHING USING A CUSTOMIZED MOUTHGUARD ON ANAEROBIC ABILITY AND VENTILATORY FLOWS

The latest findings on the ergogenic effects of a dentistry-design, bite-aligning mouthpiece require additional research to assess its impact on anaerobic ability and ventilatory parameters. This paper was aimed at determining the ergogenic acute effects of wearing a custom-made mouthpiece on oral airflow dynamics, 30-s Wingate Anaerobic Test performance parameters. Twenty-eight healthy and physically-active male subjects (age: 24.50 ± 3.32, height: 181.34 ± 7.4, weight: 78.14 ± 8.21), were voluntarily studied. The subjects were first briefed on the test protocols, and then performed the 30s Wingate test and Spirometer test. The experimental trials were performed in a random counterbalanced order. We evaluate maximum expiratory volume (VEmax L min(-1)), mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), rate to fatigue (Ws(-1)) and lactate production (mMol L(-1)), rate of perceived exertion (RPE). There were significant differences between mouthguard and no-mouthguard conditions in mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), and rate to fatigue (Ws(-1)) for the 30-s Wingate Anaerobic Test. Significantly lower lactate production (mMol L(-1)) was observed, in mouthguard condition but no significant differences were found in RPE. In airflow dynamics, the VEmax L min(-1) was significantly higher when comparing the mouthguard and the no mouthguard conditions in both forced and unforced conditions. In conclusion, wearing a customized mouthguard improves anaerobic ability and increases forced expiratory volume. This study will help practitioners improve athletes performance in anaerobic activities where high intensity action might provoke jaw-clenching, contributing in reductions of lactate and fatigue, and improving ventilatory parameters.

Effects of Jaw Clenching While Wearing a Customized Bite-Aligning Mouthpiece on Strength in Healthy Young Men.

Abstract Buscà, B, Morales, J, Solana-Tramunt, M, Miró, A, and García, M. Effects of jaw clenching while wearing a customized bite-aligning mouthpiece on strength in healthy young men. J Strength Cond Res 30(4): 1102–1110, 2016—Recent studies have investigated the ergogenic effects of different types of mouthguards. There is evidence of the benefits of clenching customized mouthpieces on force and power development. The phenomenon called concurrent activation potentiation (CAP) promoted in jaw clenching seems to enhance the muscular strength and power in maximal isometric contractions and powerful actions in sport. Moreover, a bite-aligning mouthpiece may promote a more aligned and powerful clench. The objective of the present study was to investigate the effects of jaw clenching while wearing a customized bite-aligning mouthpiece (MP) on jump ability and isometric maximal strength tests in contrast to 2 other conditions: nonjaw clenching (NON-JAW) and jaw clenching without the mouthpiece (JAW). A within-subjects design was used to assess the jump performance and the maximal isometric force in 28 physically active male subjects. Statistical analyses revealed significantly higher performance in JAW and NON-JAW conditions for handgrip force (HG-peakforce) and all variables of the back-row exercise (BRW) and countermovement vertical jump (CMVJ) (p ⩽ 0.05). Significant differences between NON-JAW and JAW were found for HG-peakforce (p ⩽ 0.05). These findings suggest that it is advisable to use a customized bite-aligning mouthpiece to improve strength and power performance.

Effects of Rapid Weight Loss on Balance and Reaction Time in Elite Judo Athletes

Balance, reaction time, and strength are key factors affecting judo performance. Although ample research has been done examining potential strength changes caused by weight loss prior to competition, changes in balance and reaction time have been overlooked.nnnPURPOSEnTo examine the effects of rapid and progressive weight loss (RWL and PWL) on balance, reaction time, and strength in a group of elite judo athletes.nnnMETHODSnA total of 38 female and male judo athletes (ageu2009=u200920.6 [2.6]xa0y) completed balance, reaction-time, and strength assessments 1 wk prior to an official weigh-in (pretest) and immediately after the weigh-in (posttest). The athletes were divided into 3 groups, 1 control group who maintained regular training and eating habits, 1 experimental group who engaged in PWL (<3% reductions in body mass), and a second experimental group who used RWL techniques (>3% reductions in body mass).nnnRESULTSnThe RWL group showed significant decreases (Pu2009<u2009.05) in balance performance (ellipse area: 4.83 [0.87] vs 6.31 [1.39]xa0mm2 with eyes closed; mean mediolateral velocity: 2.07 [0.2] vs 2.52 [0.45]xa0mm·s-1 with eyes closed; and mean anteroposterior velocity: 2.25 [0.20] vs 2.51 [0.32]xa0mm·s-1 with eyes open and 2.44 [0.26] vs 3.06 [0.56]xa0mm·s-1 with eyes closed) and reaction time (0.38 [0.04] vs 0.42 [0.06]xa0s) with no changes in strength from pretesting to posttesting. The athletes in the PWL and control groups maintained performance in all variables.nnnCONCLUSIONnThese findings demonstrate negative effects on perceptual motor-skill performance in judo athletes engaging in RWL strategies prior to competition.

Effects of jaw clenching wearing customized mouthguards on agility, power and vertical jump in male high-standard basketball players

Background/Objective Basketball players commonly use mouthguards for protecting their mouths from collisions with other players. Besides, literature reports that specific types of mouthguards may become an ergogenic device that facilitates a powerful jaw clenching, and a subsequent concurrent activation potentiation through this remote voluntary contraction of the mandible muscles. Methods A randomized within-subjects design was used to study the effects of this mechanism on muscular performance (vertical jump, agility, bench press power and leg press power) into two different conditions (mouthguard and no mouthguard) in high-standard basketball players (n = 13). A mean differences analysis and a responder analysis were conducted. Results Significant improvements were found (p < 0.05) in all vertical jump protocols using the mouthguard when compared to the no mouthguard conditions. However, no significant differences were found between the two conditions in agility and power (except in one load of bench press). Nevertheless, p-values were closer to statistical significance when analyzing the total time for the agility T-Test than when the first split time was under consideration (p = 0.111 and p = 0.944, respectively). Conclusion This study demonstrated that the use of custom-made, bite-aligning mouthguard had an ergogenic effect on jump outcomes and inconclusive results in agility T-Test in professional basketball players. From the results obtained in the present study, the use of this type of mouthguards seems to be more justified in power actions on the court than in the strength and conditioning sessions at the gym in well-trained players.

Heart Rate Variability in Elite Synchronized Swimmers

PURPOSEnTo determine whether heart-rate variability (HRV) was correlated with other training-load and training-tolerance markers for monitoring the effect of a training session on elite synchronized swimmers.nnnMETHODSnThe authors recorded the resting HRV of 12 elite swimmers (mean ageu2009=u200921.5 [3.5]xa0y) 3 times over 1 wk with a cadence of 48xa0h prior to the 2015 World Swimming Championships. They continuously monitored heart rate and obtained salivary cortisol (SC) samples before and after the last training session of the week. The authors measured capillary blood lactate (La) 2, 4, and 8xa0min after the last training session and monitored recovery HRV. They assessed rating of perceived exertion (RPE) over the entire session and tested the association between the highest La concentration (Lapeak), SC, and RPE and relative changes (Δ%) in the natural logarithm of the root-mean-square successive difference of intervals (LnRMSSD). The authors also calculated the smallest worthwhile change of the averaged pre and post LnRMSSD measurements.nnnRESULTSnThere were periods of pronounced bradycardia (60.5 [16.7]xa0beats/min) during training exercises corresponding to apneic exercise. The magnitude-based inferences showed nonclinically meaningful changes of LnRMSSD. Lapeak (6.8 [2.7] mmol/L) correlated positively with Δ%LnRMSSD and Δ%SC (ru2009=u2009.89, Pu2009=u2009.001 and ru2009=u2009.61, Pu2009=u2009.04, respectively).nnnCONCLUSIONSnThere was no change in LnRMSSD and Lapeak, Δ%SC, and RPE indicated reduced sympathetic activation and positive adaptation to the stress imposed by the session. Isolated HRV assessment may reveal a controversial interpretation of autonomic nervous system status or the training tolerance in elite synchronized swimming athletes due to the influence of the diving response.

Relationship between agility and jump ability in amateur beach volleyball male players

Agility and quickness is required by the beach volleyball players, such as sudden falls, short sprints and jumps. The surface where the beach volleyball is played constitutes a different paradigm to study these actions. This paper analyses the relationship between the agility test and the ability to jump on the sand among beach volleyball players. The study also shows the relationship between the ability to jump on rigid and sand surface. Significant correlations were found between specific agility test and both jumps test on the sand and on the rigid surface (r=-0.62 and r=-0.75, respectively). Significant differences were also found in sand tests between the national-and regional-level players. In conclusion, there was a solid relationship between jumping ability and agility of beach volleyball players. Moreover, the results of the present study reflect a surface adaptation in jumping and agility actions of more experienced players.