Detraining: loss of training-induced physiological and performance adaptations. Part II: Long term insufficient training stimulus

Effects of Whole-Season Training and Match-Play on Hip Adductor and Abductor Muscle Strength in Soccer Players: A Pilot Study

BACKGROUND

Previous investigations have associated weakness of hip muscles with a higher likelihood of developing hip groin injury. However, no previous investigation has examined the influence of soccer training and match-play during the season on maximal isometric hip adductor and abductor muscle strength.

HYPOTHESIS

Maximal hip adductor and abductor muscle strength would increase after the preseason, maintaining relatively constant levels across the soccer season.

DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 26 semiprofessional male soccer players underwent measurements of maximal isometric hip adductor and abductor muscle strength at 3 time points of the soccer season: preseason, midseason, and end-season to investigate the longitudinal effect of soccer training and competition during a complete season on maximal isometric hip adductor and abductor muscle strength in the semiprofessional Spanish soccer player.

RESULTS

Compared with preseason, hip abductor muscle strength increased in the midseason (14.2% and 17.1%, for dominant and nondominant limb, respectively; P < 0.001) and in the end-season (13.1%; P = 0.005, and 14.1%; P < 0.005). In contrast, hip adductor muscle strength remained unchanged across the season in both limbs. As a result, the adductor/abductor strength ratio in the nondominant limb was reduced at midseason and end-season time points (-14.6% and -18.4%, respectively; P < 0.001) with a corresponding tendency in the dominant limb (-9.3% and -15.0%, respectively; P > 0.05).

CONCLUSION

While maximal hip abductor muscle strength increased throughout the season, hip adductor muscle strength remained stable across the season. This produced a substantial deficit in hip adductor/abductor strength ratio at midseason and end-season.

CLINICAL RELEVANCE

The progressive imbalance in adductor/abductor strength across the soccer season may be an indicator of increased risk of groin injury and may reinforce the need for preventive rehabilitation activities focused on enhancing adductor muscle strength.

Physical Activity and Well-Being during the Second COVID19-Related Lockdown in Germany in 2021

In the second wave of the COVID-19 pandemic in Germany, lockdown measures were reinstalled and were in place between November 2020 and April 2021, including the closure of physical activity facilities. The aim of the current online survey was to assess the lockdown effects on physical activity and well-being in the general population. Pre-lockdown vs. lockdown differences were tested with the Χ2 test and the Student’s t-test for paired data. Predictor variables to explain compliance with physical activity recommendations were identified using a fixed-effects binary logistic regression analysis. Data of 993 respondents were analyzed. Transport-related and leisure-time physical activity decreased (p < 0.001, d = 0.25, and p < 0.001, d = 0.33, respectively). Compliance with physical activity recommendations decreased from 42.2% to 29.4% (chi2 (1, 1986) = 35.335, p < 0.001, V = 0.13). Well-being decreased significantly (t (990) = 23.405, p < 0.001) by 16.3 points (d = 0.74). Physical activity and well-being declined in German adults during the second COVID-19-related lockdown. Physical activity should be promoted also in light of the emerging evidence on its protective effects against COVID-19.

Exercise Training and Circulating Small Extracellular Vesicles: Appraisal of Methodological Approaches and Current Knowledge

In response to acute exercise, an array of metabolites, nucleic acids, and proteins are enriched in circulation. Collectively termed "exercise factors," these molecules represent a topical area of research given their speculated contribution to both acute exercise metabolism and adaptation to exercise training. In addition to acute changes induced by exercise, the resting profile of circulating exercise factors may be altered by exercise training. Many exercise factors are speculated to be transported in circulation as the cargo of extracellular vesicles (EVs), and in particular, a sub-category termed "small EVs." This review describes an overview of exercise factors, small EVs and the effects of exercise, but is specifically focused on a critical appraisal of methodological approaches and current knowledge in the context of changes in the resting profile small EVs induced by exercise training, and the potential bioactivities of preparations of these "exercise-trained" small EVs. Research to date can only be considered preliminary, with interpretation of many studies hindered by limited evidence for the rigorous identification of small EVs, and the conflation of acute and chronic responses to exercise due to sample timing in proximity to exercise. Further research that places a greater emphasis on the rigorous identification of small EVs, and interrogation of potential bioactivity is required to establish more detailed descriptions of the response of small EVs to exercise training, and consequent effects on exercise adaptation.

A Preliminary Study of Pre-Season Taekwondo Preparation Strategy: Personal Isolation Training Effect for Elite Athletes

Background: The global coronavirus disease pandemic (COVID-19) has had a considerable impact on athletic competition and team sports training. Athletes have been forced to train alone at home. However, the isolation training model effects are still unknown. Purpose: This study compared the effects of personal isolation training (PIT) and detraining (DT) on specific sport performances (flexibility, power, reaction time, acceleration, and aerobic capacity) and body composition in elite taekwondo athletes. Methods: Eleven elite taekwondo athletes were recruited as voluntary subjects. Athletes were randomly paired by weight into the personal isolation training group (PIT group: N = 5, age: 21.2 ± 0.4 years, BMI: 22.2 ± 0.8 kg/m²) or detraining group (DT group: N = 6, age: 19.8 ± 0.3 years, BMI: 23.1 ± 1.0 kg/m²). All subjects performed the same training content prior to the pre-test (T1). When the pre-test was completed, all subjects underwent 12 weeks of PIT or DT. Athletes were then administrated the post-test (T2). The athlete’s sport performances and body composition were measured to compare the differences between the two groups (PIT and DT) and two phases (T1 and T2). Results: There were no significant differences in kicking reaction time and flexibility in both groups (p > 0.05). The PIT showed significant improvements in 10 m (10M) sprint performance (p < 0.05), and displayed a progress trend in Abalakov jump performance. In addition, the PIT resulted in a better change response in 10M sprint performance (PIT: −4.2%, DT: +2.1%), aerobic endurance performance (PIT: −10.2%, DT: −18.4%), right arm muscle mass (PIT: +2.9%, DT: −3.8%), and trunk muscle mass (PIT: +2.2%, DT: −1.9%) than DT (p < 0.05). The fat mass percentage showed a negative change from T1 to T2 in both groups (p < 0.05). Conclusions: PIT showed a trend toward better body composition (arm and trunk muscle) and sport performances (10M sprint and aerobic capacity) compared to DT. This finding may provide information on the effectiveness of a personal isolation training model for optimal preparation for taekwondo athletes and coaches. It may also serve as a useful and safe guideline for training recommendations during the coronavirus disease (COVID-19).

The Impact of COVID-19 on the Preparation for the Tokyo Olympics: A Comprehensive Performance Assessment of Top Swimmers

BACKGROUND

The Olympic preparation of athletes has been highly influenced by COVID and post-COVID syndrome. As the complex screening of athletes is essential for safe and successful sports, we aimed to repeat the 2019-year sports cardiology screening of the Olympic Swim Team before the Olympics and to compare the results of COVID and non-COVID athletes.

METHODS

Patient history, electrocardiogram, laboratory tests, body composition analysis, echocardiography, cardiopulmonary exercise test (CPET) were performed. We used time-ranking points to compare swimming performance.

RESULTS

From April 2019, we examined 46 elite swimmers (24 ± 4 years). Fourteen swimmers had COVID infection; all cases were mild. During CPET there was no difference in the performance of COVID (male: VO2 max 55 ± 4 vs. 56.5 ± 5 mL/kg/min, p = 0.53; female: VO2 max 54.6 ± 4 vs. 56 ± 5.5 mL/kg/min, p = 0.86) vs. non-COVID athletes (male VO2 max 56.7 ± 5 vs. 55.5 ± 4.5 mL/kg/min, p = 0.50; female 49.6 ± 3 vs. 50.7 ± 2.6 mL/kg/min, p = 0.47) between 2019 and 2021. When comparing the time results of the National Championships, 54.8% of the athletes showed an improvement (p = 0.75).

CONCLUSIONS

COVID infection with short-term detraining did not affect the performance of well-trained swimmers. According to our results, the COVID pandemic did not impair the effectiveness of the preparation for the Tokyo Olympics.

Comprehensive Return to Competitive Distance Running: A Clinical Commentary

Running injuries are very common, and there are well-established protocols for clinicians to manage specific musculoskeletal conditions in runners. However, competitive and elite runners may experience different injuries than the average recreational runner, due to differences in training load, biomechanics, and running experience. Additionally, injury-specific rehabilitation protocols do not consider the broader goal of return to competitive running, including the unique psychosocial and cardiorespiratory fitness needs of elite athletes. This review aims to suggest a guideline for running-specific progression as part of a comprehensive rehabilitation program for injured competitive runners. Tools to evaluate an athlete's psychosocial preparedness to return to competition are presented. Recommendations are also provided for monitoring cardiorespiratory fitness of injured runners, including the nuances of interpreting these data. Finally, a six-phase training paradigm is proposed to guide clinicians as they help competitive runners transition from the early stages of injury through a full return to competition.

Hip Muscle Strength Explains Only 11% of the Improvement in HAGOS With an Intersegmental Approach to Successful Rehabilitation of Athletic Groin Pain

BACKGROUND

Exercise-based rehabilitation targeting intersegmental control has high success rates and fast recovery times in the management of athletic groin pain (AGP). The influence of this approach on hip strength and lower limb reactive strength and how these measures compare with uninjured athletes (CON) remain unknown. Additionally, the efficacy of this program after return to play (RTP) has not been examined.

PURPOSE

First, to examine differences in isometric hip strength, reactive strength, and the Hip and Groin Outcome Score (HAGOS) between the AGP and CON cohorts and after rehabilitation; second, to examine the relationship between the change in HAGOS and the change in strength variables after rehabilitation; last, to track HAGOS for 6 months after RTP.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 42 athletes diagnosed with AGP and 36 matched controls completed baseline testing: isometric hip strength, lower limb reactive strength, and HAGOS. After rehabilitation, athletes with AGP were retested, and HAGOS was collected at 3 and 6 months after RTP.

RESULTS

In total, 36 athletes with AGP completed the program with an RTP time of 9.8 ± 3.0 weeks (mean ± SD). At baseline, these athletes had significantly lower isometric hip strength (abduction, adduction, flexion, extension, external rotation: d = -0.67 to -1.20), single-leg reactive strength (d = -0.73), and HAGOS (r = -0.74 to -0.89) as compared with the CON cohort. Hip strength (d = -0.83 to -1.15) and reactive strength (d = -0.30) improved with rehabilitation and were no longer significantly different between groups at RTP. HAGOS improvements were maintained or improved in athletes with AGP up to 6 months after RTP, although some subscales remained significantly lower than the CON group (r = -0.35 to -0.51). Two linear regression features (hip abduction and external rotation) explained 11% of the variance in the HAGOS Sports and Recreation subscale.

CONCLUSION

Athletes with AGP demonstrated isometric hip strength and reactive strength deficits that resolved after an intersegmental control rehabilitation program; however, improved hip strength explained only 11% of improvement in the Sports and Recreation subscale. HAGOS improvements after pain-free RTP were maintained at 6 months.

Perceived anxiety and physical activity behaviour changes during the early stages of COVID-19 restrictions in community-dwelling adults in Canada: a cross-sectional study

OBJECTIVES

The COVID-19 pandemic changed daily routines, including physical activity, which could influence physical and mental health. In our study, we describe physical activity and sedentary behaviour patterns in relation to the pandemic and estimate associations between anxiety and physical activity and sedentary behaviour in community-dwelling adults.

DESIGN

Cross-sectional study.

SETTING

Calgary, Alberta, Canada.

PARTICIPANTS

Between April and June 2020, a random sample of 1124 adults (≥18 years) completed an online questionnaire.

PRIMARY AND SECONDARY OUTCOMES

The online questionnaire captured current walking, moderate intensity, vigorous intensity and total physical activity and sedentary behaviour (ie, sitting and leisure-based screen time), perceived relative changes in physical activity, sedentary and social behaviours since the pandemic, perceived seriousness and anxiety related to COVID-19, and sociodemographic characteristics. Differences in sociodemographic characteristics, perceived relative change in behaviour and current physical activity and sedentary behaviour were compared between adults with low and high anxiety.

RESULTS

Our sample (n=1047) included more females (60.3%) and fewer older adults (19.2%). Most participants (88.4%) considered COVID-19 as extremely or very serious and one-third (32.9%) felt extremely or very anxious. We found no differences (p>0.05) in current physical activity or sedentary behaviour by anxiety level. The largest perceived change in behaviours included social distancing, driving motor vehicles, use of screen-based devices, watching television and interactions with neighbours. We found anxiety-related differences (p<0.05) in perceived changes in various behaviours.

CONCLUSIONS

Changes in physical activity, sedentary behaviour and social behaviour occurred soon after the COVID-19 pandemic was declared, and some of these changes differed among those with low and high anxiety.

Periodization and Block Periodization in Sports: Emphasis on Strength-Power Training-A Provocative and Challenging Narrative

ABSTRACT

Stone, MH, Hornsby, WG, Haff, GG, Fry, AC, Suarez, DG, Liu, J, Gonzalez-Rave, JM, and Pierce, KC. Periodization and block periodization in sports: emphasis on strength-power training-a provocative and challenging narrative. J Strength Cond Res 35(8): 2351-2371, 2021-Periodization can be defined as a logical sequential, phasic method of manipulating fitness and recovery phases to increase the potential for achieving specific performance goals while minimizing the potential for nonfunctional over-reaching, overtraining, and injury. Periodization deals with the micromanagement of timelines and fitness phases and is cyclic in nature. On the other hand, programming deals with the micromanagement of the training process and deals with exercise selection, volume, intensity, etc. Evidence indicates that a periodized training process coupled with appropriate programming can produce superior athletic enhancement compared with nonperiodized process. There are 2 models of periodization, traditional and block. Traditional can take different forms (i.e., reverse). Block periodization has 2 subtypes, single goal or factor (individual sports) and multiple goals or factors (team sports). Both models have strengths and weaknesses but can be "tailored" through creative programming to produce excellent results for specific sports.

Effects of the COVID-19 Lockdown on Neuromuscular Performance and Body Composition in Elite Futsal Players

ABSTRACT

Spyrou, K, Alcaraz, PE, Marín-Cascales, E, Herrero-Carrasco, R, Cohen, DD, Calleja-Gonzalez, J, Pereira, LA, Loturco, I, and Freitas, TT. Effects of the COVID-19 lockdown on neuromuscular performance and body composition in elite futsal players. J Strength Cond Res 35(8): 2309-2315, 2021-Recent world events (i.e., COVID-19 pandemic) led to an unparalleled situation in sports. Players were forced to stay at home for a prolonged period and not allowed to use their team's training facilities or even exercise outdoors. The main aim of this study was to examine the effects of the COVID-19 lockdown on neuromuscular performance and body composition in futsal players. Ten elite male players performed a 10-m sprint, horizontal and vertical jump, and body composition measurements before and after the quarantine (i.e., 70 days). Pre-post confinement differences in horizontal jump distance, countermovement jump variables, sprinting time, and body composition were analyzed by a paired sample t-test and effect sizes (ESs). A large and significant decline was observed in sprint ability (p = 0.004; ES = 1.31). Small and nonsignificant differences were found in horizontal jump performance (p = 0.243; ES = -0.39). Nonsignificant differences were observed in countermovement jump (CMJ) height (p = 0.076; ES = -0.63) but moderate-to-large significant declines were found in CMJ eccentric deceleration impulse, rate of force development, peak power, velocity, and landing peak force (p ≤ 0.05; ES = -0.52 - 1.23). Finally, trivial and nonsignificant differences were obtained on body composition parameters. In summary, sprint performance and specific CMJ kinetic variables were significantly affected by long-term reduced training, whereas vertical jump height and horizontal jump distance and body composition were not. Practitioners are advised to implement efficient sprint-oriented and eccentric-oriented training strategies to optimize return to competition after prolonged detraining periods.

Effect of Online Training during the COVID-19 Quarantine on the Aerobic Capacity of Youth Soccer Players

Motor abilities, such as endurance and the optimal level of physical activity, play a fundamental role in football as they are necessary to maintain the high effectiveness of the training process. The aim of this study was the observation of the trend of changes in the level of cardiorespiratory endurance of young football players in a one-year cycle overlapping with the COVID-19 lockdown and an assessment of the impact of the training intervention during home confinement. The participants of the study were 24 young football players. We analysed the results of the study in a one-year training cycle (lockdown from 11 March 2020 to 6 May 2020). The cardiorespiratory endurance was measured using the Multistage 20 m Shuttle Run test—Beep Test. A repeated measures analysis of variance was used in the study. Detailed comparisons were made using Tukey’s HSD test. Statistically significant differences were noted in endurance in a one year cycle: F(5.115) = 22.65; p < 0.001; partial Eta-squared = 0.50. An increase in the level of endurance by mean = 179.17 m, SD ± 189.87 m was noted between T1 and T6. After the break caused by the COVID-19 restrictions, a decrease in the level of cardiorespiratory endurance was noted. Only after two training mesocycles was a significant increase in the mean value noted compared to the period before the pandemic (p < 0.05). With the negative impact of restrictions in mind, coaches and physiotherapists should exercise caution when planning training, taking into consideration the level of physical activity during the pandemic.

Effects of Physical Activity and Training Routine on Mental Health During the COVID-19 Pandemic and Curfew

This research aimed to explore the effects of physical activity and training routine on mental health during the COVID-19 pandemic and the proclaimed emergency state and curfew. To measure the mental health components of psychological distress and subjective well-being, two studies were conducted on different samples: Study 1 during the beginning of curfew in Serbia (N = 678) and Study 2 during the ending phase (N = 398). The results of Study 1 showed that elite athletes as well as those with high level of physical activity experienced the lowest distress. Furthermore, effects of the changes in the training routine on distress among physically active individuals depended on the level of sports participation with elite athletes who reduced trainings showing lower anxiety compared to recreational athletes who reduced trainings as well or kept the same training routine. Thus, we could conclude that in the early stage of the pandemic, elite athletes showed better mental health and adaptability to the crisis situation. Results of Study 2 showed that although all the participants had decreased well-being during the curfew, compared to the period before the pandemic and the curfew, there were no differences in well-being between elite and recreational athletes, who had higher well-being compared to non-athletes. However, this effect held both before and during the curfew showing that physically active individuals did not additionally benefit from this decrease compared to the non-active. Furthermore, athletes who became physically inactive showed lower well-being compared to those who kept the same training routine. Thus, in the later stage of the pandemic, prolonged physical inactivity had negative effects on mental health.

Training Load and Performance Impairments in Professional Cyclists During COVID-19 Lockdown

Purpose: The COVID-19 outbreak has challenged professional athletes’ training and competition routines in a way not seen before. This report aims to inform about the changes in training volume and intensity distribution and their effects on functional performance due to a 7-week home-confinement period in professional road cyclists from a Union Cycliste Internationale Pro Team. Methods: A total of 18 male professional cyclists (mean [SD] age = 24.9 [2.8] y, body mass = 66.5 [5.6] kg, maximal aerobic power = 449 [39] W; 6.8 [0.6] W/kg) were monitored during the 10 weeks before the lockdown (outdoor cycling) and the 7-week lockdown (indoor cycling turbo trainer). Data from the mean maximal power output (in watts per kilogram) produced during the best 5-minute and best 20-minute records and the training intensity distributions (weekly volumes at power-based training zones) were collected from WKO5 software. Results: Total training volume decreased 33.9% during the lockdown (P < .01). Weekly volumes by standardized zones (Z1 to Z6) declined between 25.8% and 52.2% (effect size from 0.83 to 1.57), except for Z2 (P = .38). There were large reductions in best 5-minute and best 20-minute performance (effect size > 1.36; P < .001) with losses between 1% and 19% in all the cyclists. Conclusions: Total indoor volumes of 12 hours per week, with 6 hours per week at low intensity (Z1 and Z2) and 2 hours per week at high intensity over the threshold (Z5 and Z6), were insufficient to maintain performance in elite road cyclists during the COVID-19 lockdown. Such performance declines should be considered to enable a safe and effective return to competition.

Impact of COVID-19 on Swimming Training: Practical Recommendations during Home Confinement/Isolation

The COVID-19 pandemic has had severe effects on communities globally, leading to significant restrictions on all aspects of society, including in sports. Several significant decisions were made to postpone or cancel major swimming events by FINA (Fédération Internationale de Natation). Swimmers were no longer allowed to continue their usual training in swimming pools and were confined to their homes. These unusual circumstances may represent a good opportunity to strengthen different areas of swimmer preparation and potentially enhance performance when resuming regular aquatic training. We searched major databases for relevant information, and the present article provides practical information on home-based training for swimmers of all ages. The COVID-19 crisis and its consequences on the swimming community have created a myriad of challenges for swimmers around the world, including maintaining their fitness level and preparing to return optimally and safely to pool training and competitions. Unfortunately, the mental consequences that might arise after the pandemic may also have an impact. We strongly recommend encouraging the swimmers to consider quarantine as an opportunity for development in specific areas of preparation and learn how to best cope with this special situation of self-isolation and/or "physical distancing" for their mental health and in case a similar situation is faced again in the future.

Maintaining Physical Performance: The Minimal Dose of Exercise Needed to Preserve Endurance and Strength Over Time

ABSTRACT

Maintaining physical performance: the minimal dose of exercise needed to preserve endurance and strength over time, Spiering, BA, Mujika, I, Sharp, MA, and Foulis, SA. J Strength Cond Res 35(5): 1449-1458, 2021-Nearly every physically active person encounters periods in which the time available for exercise is limited (e.g., personal, family, or business conflicts). During such periods, the goal of physical training may be to simply maintain (rather than improve) physical performance. Similarly, certain special populations may desire to maintain performance for prolonged periods, namely athletes (during the competitive season and off-season) and military personnel (during deployment). The primary purpose of this brief, narrative review is to identify the minimal dose of exercise (i.e., frequency, volume, and intensity) needed to maintain physical performance over time. In general populations, endurance performance can be maintained for up to 15 weeks when training frequency is reduced to as little as 2 sessions per week or when exercise volume is reduced by 33-66% (as low as 13-26 minutes per session), as long as exercise intensity (exercising heart rate) is maintained. Strength and muscle size (at least in younger populations) can be maintained for up to 32 weeks with as little as 1 session of strength training per week and 1 set per exercise, as long as exercise intensity (relative load) is maintained; whereas, in older populations, maintaining muscle size may require up to 2 sessions per week and 2-3 sets per exercise, while maintaining exercise intensity. Insufficient data exists to make specific recommendations for athletes or military personnel. Our primary conclusion is that exercise intensity seems to be the key variable for maintaining physical performance over time, despite relatively large reductions in exercise frequency and volume.

Active Older Adults Keep Aerobic Capacity and Experience Small Reductions in Body Strength During Confinement Due to COVID-19 Outbreak

The objective of this study was to observe the home-confinement effects on physical fitness, physical activity (PA), and body composition in active older adults, and to compare physical fitness and PA according to quality of life (QoL) during confinement. A total of 72 physically active older adults (61.1% females; 74.24 ± 5.57 years) were assessed pre- and postconfinement for aerobic capacity (6-min walk test), lower (30-s sit-to-stand), and upper (30-s arm-curl) body strength, PA (short-version of the International Physical Activity Questionnaire), and QoL (EQ-5D-visual analogue scale). The pre- and postconfinement comparisons show declines in upper (-2.24 ± 0.45 repetitions; p < .001; η2 = .276) and lower body strength (-2.65 ± 0.42 repetitions; p < .001; η2 = .378) in both genders, but not in aerobic capacity. Ninety percentage of older adults perceived a decline in PA. Older adults reporting high QoL increased 19.27 ± 97.04 m in the 6-min walk test, while the participants with low QoL reduced 28.32 ± 63.27 m (p = .018; η2 = .090). Previously active older adults did not have their aerobic capacity decrease significantly despite a decline in upper and lower body strength during an 11-week home confinement period.

COVID-19 pandemic impacts physical activity levels and sedentary time but not sleep quality in young badminton athletes

Purpose

Regular physical activity is a good strategy to maintain the health of athletes, and prevent pain and decreased joint flexibility during the pandemic. On the other hand, higher sedentary time during the pandemic period can have deleterious effects. The objective of this study was to compare physical activity levels, sedentary time, and sleep parameters during the pre-COVID period and the COVID-19 pandemic period in young badminton athletes.

Methods

Fifteen young badminton athletes were evaluated during a pre-COVID period (July 2019) and during the COVID-19 period (July 2020). Sleep parameters, physical activity level, and sedentary time were measured using a tri-axial accelerometer. Participants wore the accelerometer on their dominant wrist for 7 days consecutively. In addition, the average of each sleep parameter [time in bed and total sleep time in hours per day, sleep efficiency (%), wake after sleep onset (WASO, total per day), and sleep latency (minutes per day)] was reported over the 7-day period.

Results

Athletes presented increased sedentary time (pre-COVID = 7.0 ± 1.1 vs.COVID-19 = 8.9 ± 1.9 h/day, p = 0.004, d = 1.30) and significant decreases in the total PA observed in counts per day (pre-COVID = 2,967,064.4 ± 671,544.1 vs. COVID-19 = 1,868,210.2 ± 449,768.4 counts/day, p = 0.001, d = 1.99), time in vigorous PA (pre-COVID = 7.7 ± 0.9 vs. COVID-19 = 6.1 ± 1.2 h/day, p = 0.001, d = 1.56), and time in moderate-to-vigorous PA (pre-COVID = 8.1 ± 0.9 vs. COVID-19 = 6.5 ± 1.3 h/day, p = 0.001, d = 1.48). There were no significant differences for time in light and moderate PA or in sleep parameters (p > 0.05).

Conclusion

Young badminton athletes presented increased sedentary time, and decreased total physical activity, time in MVPA, and time in vigorous activities during the COVID-19 pandemic compared to the pre-COVID period, however, there were no significant differences in sleep parameters.

Effects of Home Confinement on the Intensity of Physical Activity during the COVID-19 Outbreak in Team Handball According to Country, Gender, Competition Level, and Playing Position: A Worldwide Study

This study investigated effects of home confinement on physical activity (PA) in Team Handball during the COVID-19 outbreak. A total of 1359 handball players participated (age: 23 ± 6 years). Participants from Europe, Western Asia, and North Africa answered an online version of the International Physical Activity Questionnaire (IPAQ) considering “before” and “during” confinement. COVID-19 home confinement has had a negative effect on PA (vigorous, moderate, walking, and overall). The largest decrease was in the sum parameter “all PA” (MET (metabolic equivalent of task)-min/week, η_p² = 0.903; min/week, η_p² = 0.861). Daily sitting time increased from 2.7 to 5.0 h per weekday (p < 0.001, η_p² = 0.669). For gender, continent, country, level of handball league, and playing position, no significant differences (group and interaction effects) were observed. The largest change in PA behavior was in walking (minutes per day: η_p² = 0.755), with males displaying the greatest decrease (from 62 ± 11 to 30 ± 14 min per weekday; d = 2.67). In terms of magnitude, difference between genders was greatest for sitting time (difference in d = 1.20). In conclusion, while COVID-19 measures were essential to preserve public health, PA was compromised and sedentary behavior increased because of these public health measures regardless of gender, playing position, and competition level.

Resting Heart Rate Measurement in Elite Athletes during COVID-19 Lockdown: The Impact of Decreased Physical Activity

The purpose was to observe the effects of a four-week lockdown on the resting heart rate (RHR) and well-being perception of elite swimmers. Twenty elite swimmers performed RHR measurements upon waking in supine and standing positions. Baseline values and those measured after four weeks of lockdown were compared. Swimmers completed a questionnaire on their training volume and state of well-being. During the lockdown, swimmers reported a weekly mean physical activity of 10.4 ± 3.6 h (an estimated reduction of 254% compared to their usual training volume). After four weeks of lockdown, RHR in the supine position increased by more than two beats per minute (58.8 ± 8.2 vs. 56.5 ± 7.4 bpm, p < 0.05). In the standing position, RHR increased by almost 15 beats per minute (103.3 ± 13.2 vs. 88.4 ± 9.4 bpm, p < 0.0001). Fifty percent of these athletes expressed a decrease in well-being. These results underline that the lockdown circumstances induced a large reduction in parasympathetic activity in elite athletes, which was associated with a decrease in training volume. This increase in RHR may reflect that a highatly strenuous environment and maintaining a high level of physical activity in this population could be favorable to preserve physical and psychological health.

Effects of a 48-Day Home Quarantine during the Covid-19 Pandemic on the First Outdoor Running Session among Recreational Runners in Spain

COVID-19-induced quarantine may lead to deleterious effects on health status as well as to impaired performance and increased injury risk when re-starting training after lockdown. We investigated the physical activity (PA) habits of recreational runners in Spain during a 48-day home quarantine during the COVID-19 pandemic and the characteristics of the first outdoor running session after confinement. A cross-sectional study, including a self-reported running questionnaire completed after the first outdoor running session after quarantine, was performed. Three hundred recreational runners (74% males; 60% 18-40 years old; most typical running experience >3 years, 10-30 km weekly running distance distributed in 3-4 sessions) were considered for analysis. Advanced runners ran, at least, 4 days/week and participated in running events. They performed significantly longer and more non-supervised weekly training sessions during confinement (p < 0.01 for both) than novice and amateur runners. Most runners performed their first outdoor running session on asphalt (65.3%) and ran 5 to 10 km (61%) at a pace above 5 min/km (60%), reporting no pain before (77%), during (64%), and 24 h after (76%) the session. Advanced runners performed a significantly longer running session, at a higher pace, and covered a greater distance (p < 0.01 for all) than novice and amateur runners, while enjoyment and motivation tended to be significantly higher when runners' level increased (p < 0.05). Higher training levels prior to and during confinement may lower the collateral effects (e.g., detraining, injury risk) of home quarantine when runners return to previous PA levels.

Maximal Strength, Sprint, and Jump Performance in High-Level Female Football Players Are Maintained With a Customized Training Program During the COVID-19 Lockdown

INTRODUCTION

The COVID-19 outbreak with partial lockdown has inevitably led to an alteration in training routines for football players worldwide. Thus, coaches had to face with the novel challenge of minimizing the potential decline in fitness during this period of training disruption.

METHODS

In this observational pre- to posttest study involving Norwegian female football players (18.8 ± 1.9 years, height 1.68 ± 0.4 m, mass 61.3 ± 3.7 kg), we investigated the effects of a prescribed home-based and group-based intervention, implemented during the COVID-19 lockdown, on maximal muscular force production and high velocity variables. Specifically, maximal partial squat strength one repetition maximum (1RM), counter movement jump (CMJ) and 15 m sprint time were assessed 1 week prior to the lockdown and 12 weeks after the onset of lockdown. We also collected training content and volume from the prescribed training program and self-reported perceived training quality and motivation toward training.

RESULTS

We observed no change in 1RM [pretest: 104 ± 12 kg, posttest: 101 ± 11 kg (P = 0.28)], CMJ height [pretest: 28.1 ± 2.3 cm, posttest: 26.8 ± 1.9 (P = 0.09)], and 15 m sprint time [pretest: 2.60 ± 0.08 s, posttest: 2.61 ± 0.07 s (P = 0.52)].

CONCLUSION

Our findings suggest that a prescribed home-based and group-based intervention with increased training time devoted to strength, jump, and sprint ability, and regulated to obtain a sufficient infection control level is feasible and effective to preserve strength, jumping, and sprinting abilities of high-level female football players during a ∼ 3-month period of a pandemic-induced lockdown.

Effects of an experimental taper period on male and female swimmers

BACKGROUND

This study investigated the possible influence of the gender on the responses of swimmers during a taper period (TP).

METHODS

Ten males (19 ± 3 years and 73.5 ± 7.8 kg) and ten females (17 ± 2 years and 54.7 ± 7.2 kg) swimmers were submitted to a 12-week training, followed by three weeks of the TP. Before and after the TP we evaluated the performance at 100 m freestyle, stroke parameters and lactacidemic responses; lactate minimum intensity (LMI) and stroke parameters associated with LMI and the propulsive force in tethered swimming. TP consisted of 14 sessions with mean volume 2,253 ± 1,213 m•session-1 at an intensity below than the LMI, 1,730 ± 327 m•session-1 at an intensity near the LMI and 1,530 ± 1,019 m•session-1 at an intensity above the LMI.

RESULTS

Significant effects of the genders were observed for LMI and stroke parameters (p-value < 0.001 and η2 > 0.52 [large]) and propulsive force (p-value = 0.001; η2 = 0.59 [large]). However, no significant effects of the TP were identified in the performance of the 100 m freestyle (p-value = 0.66; η2 = 0.006 [small]), propulsive force (p-value > 0.63; η2 < 0.006 [small]), aerobic parameters (LMI: p-value = 0.32 and η2 = 0.03 [small]) and mechanical parameters (p-value > 0.23; η2 = 0.01 [small]). Nonetheless, the peak blood lactate concentrations were improved after TP (p-value = 0.014; η2 = 0.16 [large]), without significant interactions (p-value = 0.38; η2 = 0.02 [small]), as well as the mechanical parameters during maximum 100 m freestyle (p-value < 0.04 and η2 > 0.10 [medium]).

CONCLUSIONS

Hence, men and women presenting significantly different values in the age group studied, the responses observed after the TP investigated were the same independent of gender.

The dose-response relationship between interval-training and VO2max in well-trained endurance runners: A systematic review

Success in endurance running is primarily determined by maximal aerobic power (VO_2max), fractional utilization, and running economy (RE). Within the literature, two training modalities have been identified to improve VO_2max; continuous training (CT) and interval-training (IT). The efficacy of IT to improve VO_2max in well-trained runners remains equivocal, as does whether a dose-response relationship exists between the IT training load performed and changes in VO_2max. A keyword search was performed in five electronic databases. Seven studies met the inclusion criteria for this systematic review. The training impulse (TRIMP) was calculated to analyse relationships between training load and changes in VO_2max, by calculating the time accumulated in certain intensity domains throughout a training intervention. Non-significant (P>0.05) improvements in VO_2max were reported in six studies, with only one study reporting a significant (P<0.05) improvement following the IT interventions. A relationship between the training session impulse of the interval-training performed (IT S_TRIMP) and VO_2max improvements were observed. The efficacy of IT to improve VO_2max in well-trained runners remains equivocal, nevertheless, the novel method of training-load analysis demonstrates a relationship between the IT S_TRIMP and VO_2max improvements. This provides practical application for the periodization of IT within the training regime of well-trained distance runners.

The Impact of the COVID-19 Pandemic on US College Students' Physical Activity and Mental Health

BACKGROUND

Investigating the impact of the COVID-19 pandemic on both physical activity (PA) and mental health is important to demonstrate the need for interventions. This study examined the apparent impact of the pandemic on college students' PA, perceived stress, and depressive symptoms.

METHODS

From 2015 through 2020, data were collected at the beginning and end of the spring semester at a large Northeastern US university via an online survey assessing student demographics, PA, perceived stress, and depressive symptoms. Mixed ANOVA examined differences in PA and mental health changes over the spring semester between "normal" and COVID-19 circumstances. Two-way ANOVA examined the interaction between circumstance and changes in PA in relation to changes in mental health.

RESULTS

Participants (n = 1019) were predominately women and non-Hispanic white. There was a significant decline in PA and an increase in perceived stress under COVID-19, but not normal, circumstances and a significant increase in depressive symptoms under COVID-19, but not normal, circumstances among women.

CONCLUSIONS

A significant decline in PA and mental health among college students occurred under COVID-19 circumstances, and PA did not appear to protect against deterioration in mental health. Proactive and innovative policies, programs, and practices to promote student health and well-being must be explored immediately.

Case Report: Return to Sport Following the COVID-19 Lockdown and Its Impact on Injury Rates in the German Soccer League

The Bundesliga made headlines for becoming the first major sports league to return to sport worldwide following COVID-19 lockdown. To-date, there lacks retrospective studies on longitudinal injury rates to elucidate the effect isolation measures had on the health and safety of professional athletes. This study sought to compare injury rates experienced by Bundesliga athletes before and after the COVID-19 lockdown. Data was collected from public injury and player reports regarding the Bundesliga, with injury defined as trauma resulting in loss of game time. Descriptive statistics were used to present differences in injury incidence between all Bundesliga Match days pre- and post-lockdown. Between the league's resumption and completion on May 16 and June 27, 2020, injuries occurred in 21 forwards (FW), 11 central midfielders (CM), 12 wide midfielders (WM), 16 central defenders (CD), 6 fullbacks (FB), and 2 goalkeepers. Players had 1.13 (95% CI 0.78, 1.64) times the odds of being injured following the COVID-19 lockdown, with a 3.12 times higher rate of injury when controlling for games played compared to injury rates pre-lockdown (0.84 injuries per game vs. 0.27 injuries per game). The most frequent injury group was muscular injuries with 23 injuries total, with 17% of athletes experiencing injury during their first competitive match following lockdown. Injury rate increased over 3-fold following COVID-19 lockdown. Athletes did not experience an increased rate of injury with more cumulative competitive matches played. High injury incidence for players yet to complete their first competitive match may imply suboptimal sport readiness following home confinement.

Physical performance of military personnel before and during the Covid-19 pandemic

ABSTRACT This investigation aimed to compare the level of physical performance of the military of the 3rd Military Police Battalion before and during the COVID-19 pandemic. The participants were 82 military personnel (76 men) who were submitted to the Physical Fitness Test (PFT) in November 2019 and repeated it in September 2020. The 12-minute and VO2max tests were selected for cardiorespiratory evaluation and push-ups and sit-up tests to assess localized muscle resistance. The results showed a decrease in the performance of these soldiers, both in cardiorespiratory variables and in localized muscular resistance (p ≤ 0.05). The pandemic may have negatively influenced the physical performance of the military.

The Impact of COVID-19-Related Shutdown Measures on the Training Habits and Perceptions of Athletes in the United States: A Brief Research Report

The purpose of the current study was to examine the impact of COVID-19 government-enforced shutdown measures on the training habits and perceptions of athletes. A web-based electronic survey was developed and distributed online to athletes. The survey contained questions regarding currently available resources, changes in weekly training habits, and perceptions of training such as intensity, motivation, and enjoyment. A total of 105 (males: n = 31; females: n = 74) athletes completed the survey (mean ± SD age = 19.86 ± 2.13 years). Ninety-nine (94.3%) athletes continued to receive guidance from their primary sport coach or strength training staff. There was a significant (p < 0.001) decrease (mean ± SD) in self-reported participation time for strength training (-1.65 ± 4.32 h. week^-1), endurance (-1.47 ± 3.93 h. week^-1), and mobility (-1.09 ± 2.24 h. week^-1), with the largest reduction coming from participation time in sport-specific activities (-6.44 ± 6.28 h. week^-1) pre- to post-shutdown. When asked to rate their current state of emotional well-being using a visual analog scale of 0-100, with 100 being exceptional, the mean score was 51.6 ± 19.6 AU. Athletes experienced notable reductions in training frequency and time spent completing various training related activities. In the future, practitioners should have preparations in place in the event of another lockdown period or future pandemic to avoid or minimize significant disruptions in training. Special considerations may be needed when athletes are allowed to return to sport in the event of significant levels of detraining that may have occurred.

Maintenance motives for physical activity among older adults: a systematic review and meta-analysis

The purpose of this systematic review was to examine if the motives of satisfaction with outcomes, enjoyment of behavior, self-determination, and identity are related to physical activity (PA) maintenance in older adults. We also explored whether the strength of these associations varies as a function of sample characteristics (i.e., age, gender, physical health status) and maintenance context. Five electronic databases (PubMed, PsycINFO, SportDiscus, CINAHL, and ProQuest Dissertations and Theses) were searched, and sixteen studies (k) with a sample mean age ≥ 55 years were included. When the number of studies was ≥ 5 for a given motive, a pooled correlation coefficient was calculated using the inverse-variance method under the random-effects model assumption. Self-determination was positively associated with PA maintenance [r (95% CI) = 0.189 (0.127, 0.249); k = 11]. This association was stronger and more homogeneous for samples described as having a physical health condition (r = 0.212; k = 6) and studies judged to be at risk of bias due to missing data (r = 0.223; k = 8). Few studies (< 5) investigated satisfaction with outcomes, enjoyment of behavior, and identity, which precludes any summary judgment for these three motives. PROSPERO Registration Number: CRD42018088161.

Effects of the COVID-19 confinement period on physical conditions in young elite soccer players

BACKGROUND

The rapid spread of the SARS-CoV-2 infection required general confinement measures reducing or even preventing sport practice, which was a risk of detraining in athletes. In adolescents, detraining is poorly known as well as its prevention by home-exercises. This article aimed to assess the effects of COVID-19 confinement on detraining in young high-level soccer players despite a multimodal training program conducted at home.

METHODS

Twenty-five elite soccer players, aged 14, were included to perform physical exercises at home during the COVID-19 confinement. Two cardio-training sessions and two upper and lower limb muscle strengthening sessions were performed per week. The exercise program was monitored remotely via the web. Hooper, training and mental indexes allowed a psychological follow-up. The effect of COVID-19 confinement on aerobic capacity was measured using a pre- and postconfinement Yo-Yo Test.

RESULTS

Out of the 25 adolescences who completed the exercises program, 19 performed the postconfinement Yo-Yo Test. The running distance decreased by 614+/-630 m (-25%) (P=0001) and the maximal running speed by 0.97+/-1 km/h (-5%) (P=0.001), confirming detraining. Hooper, training and mental indexes remained stable showing a well-supported home COVID-19 confinement.

CONCLUSIONS

The 2-month period of strict home confinement due to the SARS-CoV-2 pandemic was responsible for a decrease of aerobic abilities in adolescent soccer players, despite a remotely monitored multimodal exercises program.

PERCEPTIVE CHANGES IN ENDURANCE ATHLETES DURING SOCIAL ISOLATION DUE TO COVID-19

ABSTRACT Introduction: The COVID-19 pandemic has led to social isolation measures in different contexts. In endurance sports, competitions worldwide have been canceled, affecting behavioral, psychological, and physical aspects. Objective: This study aimed to assess potential associations between stress, motivation, behavioral changes, and physical fitness in endurance athletes, and time in social isolation. Methods: A cross-sectional study with the participation of 201 athletes, including mountain bikers (n = 89), runners (n = 88) and triathletes (n = 24). Each participant answered questions about time spent in isolation; body weight; changes in training schedule during the isolation period; levels of motivation; stress levels; loss of physical fitness; what aspect of physical fitness was most jeopardized during the isolation period; alcohol consumption; quality of sleep; quality of diet; and whether they had been ill during the isolation period. Results: The results showed significant differences between the percentage of runners (4.5%) and triathletes (16.7%) who had been isolated from 1-10 days, and between the percentage of cyclists (41.6%) and runners (68.2%) in 11-20 days and >20 days (28.1% and 9.1%) respectively. Social isolation was significantly associated with at least one variable for the three groups of athletes; however, the runners were the most affected by the pandemic, presenting an association with low motivation, high stress, poorer quality of sleep, increased alcohol consumption, and loss of physical fitness. Conclusion: Our study showed that the period of social isolation, specifically over time > 10 days, generated significant changes in the perceptions of motivation, stress, alcohol consumption, and physical fitness of endurance athletes, with runners being the most affected group. Level of Evidence III; Diagnostic studies - Investigation of a diagnostic test; Study of non-consecutive patients, without a “gold standard” applied uniformly.

Stay Home: Role of Physical Exercise Training in Elderly Individuals' Ability to Face the COVID-19 Infection

Recently, the novel coronavirus epidemic occurred in China and spread worldwide to become a global pandemic. COVID-19 is a fatal viral infection causing death, particularly in aged individuals, due to impaired immunity. To date, no intervention is available to prevent COVID-19 and its manifestations. Physical exercise training generally has health benefits, and it assists in the prevention of several chronic diseases. Therefore, this review is aimed at exploring the role of physical exercise training in the face of COVID-19 in older adults and elderly individuals. From this point of view, this review suggests that physical exercise training plays a key role in promoting immune system regulation, delaying immunity dysfunction, reducing circulatory inflammation markers, and preventing sarcopenia and thus could prevent the risk of acquiring COVID-19 infection and reduce the complications of recommended self-isolation in older adults and elderly individuals. Additionally, immunity biomarkers were optimistically demonstrated in older adults following physical exercise training, thereby reducing mortality and morbidity rates. Finally, in accordance with recommendations to stay home and perform self-isolation to prevent the spread of COVID-19, all populations are strongly recommended to practice regular home exercise training at home to promote immune system functioning.

Effects of kettlebell training and detraining on mood status and sleep and life quality of healthy women

BACKGROUND AND PURPOSE

Kettlebell exercise have become popular because of its ability to simultaneously train aerobic/anaerobic systems, low cost and easy access, and the great potential for physical fitness programs with a focus on public health. However, little is known about its effects on mood status, sleep, and quality of life (QOL) parameters. The aim of the present study was to examine the effects of kettlebell training/detraining on the prevention of depressive and anxiety symptoms and QOL and sleep quality.

METHODS

The sample was composed of 17 healthy women (age: 26.0 ± 5.0 years; body mass: 60.9 ± 12.5 kg; height: 164.6 ± 5.5 cm). The study was organized into four consecutive phases: pre-intervention (PRE), intervention (kettlebell training, 12 weeks, three times/week), post-intervention (POST) and detraining (D, four weeks). The questionnaires SF-36 (QOL), Beck (depressive symptoms), State-Anxiety Inventory (acute anxiety symptoms), POMS (mood state) and the Pittsburgh Sleep Quality Index (sleep quality) were administered at PRE/POST/D phases.

RESULTS

QOL, anxiety, sleep quality, and mood state exhibited no differences between PRE/POST/D. Levels of depressive symptoms significantly decreased (22.0%, p = 0.003) between PRE and POST phases, and remained low and similar to POST levels after D.

CONCLUSION

Twelve weeks of kettlebell training was able to reduce and prevent depressive/anxiety symptoms in healthy women and these results were maintained after short-term detraining. Thus, kettlebell training might be considered an alternative method on the promotion of mental health and prevention of mood disorders and consequently can improve QOL even in health people.

Monitoring Training Load in Soccer: The ROMEI Model

Montini, M and Rocchi, JE. Monitoring training load in soccer: The Relation of Ongoing Monitored Exercise in Individual model. J Strength Cond Res 12XX(2X): 000-000, 2016. For a training organization, monitoring training load (TL) is of paramount importance. Despite this, a conclusive response on such topic is yet to be reported. The aims of this study were to investigate the relationship between TL indicators and to propose a new method for monitoring TL response and physical fitness. Twenty professional soccer players were retrospectively evaluated. The first phase of data analysis included 34 in-season training sessions. Subsequently, three microcycles (T1-T2-T3) of pre-season training were processed. A regression model was used to examine the relationships between internal TL (session rating of perceived exertion [s-RPE]) and external TL (energy expenditure, EE). The standard error of the regression equation was used to propose a new model called "ROMEI" (Relation of Ongoing Monitored Exercise in Individual). The level of statistical significance was set at p < 0.05. During the competitive season and the pre-season training camp, the average TL values were 65.8 ± 22 and 58.2 ± 22 minutes; 336 ± 204 and 228 ± 101 AU of s-RPE; and 29 ± 13 and 25 ± 9 kJ kJ of EE, respectively. In the competitive season, the collective and average individual correlation coefficients between s-RPE and EE were r = 0.888 and r = 0.892 ± 0.05, respectively. Considering slope values (m) of the regression line, data highlighted a significant increase of +34.4 ± 15.9% in T2 vs. T3 (p < 0.001) and +38.2 ± 15.2% in T1 vs. T3 (p < 0.001). Data shown in this investigation support the use of an individualized analysis to better understand the TL administered to soccer players rather than a collective analysis. This may be accomplished with the proposed ROMEI model.

Short-Term Detraining Does Not Impair Strength, Speed, and Power Performance in Elite Young Soccer Players

This study aimed to examine the effects of short-term detraining on the strength, speed, and jump capacities of under-20 soccer players. Twenty-four elite under-20 soccer players from the same professional club were assessed pre and post 26 days of detraining. The measurements were performed in the following order: countermovement jump (CMJ); 10 m linear sprint velocity; and one-repetition maximum test (1RM) in the horizontal leg-press exercise. To analyze the differences between pre- and post-tests, a paired T-test was applied. The significance level was set as p < 0.05. Soccer players exhibited a significant increase in CMJ performance (p = 0.02) and no significant differences in 10 m sprint velocity and 1RM leg-press were found after the short-term training cessation (p = 0.61; p = 0.55, respectively). We demonstrated that a short-term detraining period was capable of promoting a significant increase in the vertical jump height without inducing negative effects on the strength and speed capabilities of elite under-20 soccer players. Practitioners and sport scientists should be aware of these findings to program more effective training strategies at the beginning of the subsequent training cycle.

COVID-19 AND ITS EFFECT ON OLYMPIC SPORT: THE IMPORTANCE OF STUDYING SOCIAL ISOLATION AND THE HARM IT CAUSES, IN ORDER TO MINIMIZE IT

ABSTRACT In March 2020, the World Health Organization (WHO) declared the disease caused by the SARS-CoV2 virus, known as COVID-19, to be a pandemic. The sporting world, too, is suffering from the global effects of this disease, with the postponement or cancellation of competitions, including the 2020 Tokyo Olympic Games. As a proposal for containing the disease, social isolation was declared. Despite the importance of this measure, it was harmful for Olympic athletes, as they had to stay away from their training site and trainers, as well as their interdisciplinary teams. It is therefore important to study this harm caused, in order to minimize it. In general, it is believed that regular physical activity is associated with improved immune system functioning. The lack of training can therefore have significant consequences for the performance and health of the Olympic athlete. From the athlete's point of view, the impaired immune system, due to the reduced frequency of physical exercise, leaves them more vulnerable to contracting or developing infections or other diseases. The risk of harm due to the decreased performance of preventive works is also evident in this population. The reductions in training load and intensity can cause changes in the athlete's body composition and affect various aspects of cardiorespiratory fitness, as well as reducing strength levels and muscle potency. In relation to the athlete's mental health, two aspects are particularly challenging: isolation and uncertainty. Based on the possible harm caused by social isolation, the need is seen for a specific and joint work, in an attempt to minimize it. This work addresses the following topics: (I) context: transmission, symptoms, diagnosis, treatment, discharge criteria, isolation and post-pandemic consequences; (II) harm and proposals: nutritional, physiological, biomechanical and psychological. Level of evidence II; Review Article.

Physical Performance Among Air Force ROTC Cadets Following Non-Mandatory Training

INTRODUCTION: Due to the standard collegiate academic calendar (two semesters), U.S. Air Force Reserve Officers Training Corps (ROTC) cadets have an approximate 3-mo break over the summer in which physical training (PT) is neither regulated nor required. The purpose of this investigation was to determine if significant changes in cadet physical fitness assessment (PFA) scores occur after a 3-mo summer break when training is not mandatory.METHODS: Male (N 28) and female (N 10) cadets performed the PFA in April and August. Cadets were split into two groups depending on if they participated in field training over the summer [FT; N 12 (men 6, women 6)] or did not [NFT; N 26 (men 22, women 4)] to determine if engaging in field training had any effect on performance.RESULTS: Cadets performed significantly better on run time (7%), pushups (7.6%), sit-ups (5.8%), and overall composite score (3.6%) before summer break compared to after. Significant time group interactions were observed for abdominal circumference and run time. Abdominal circumference paired samples t-tests indicated that while the FT group did not differ between the spring and fall time points, the NFT did. There was a main effect for time in which cadets had a significantly larger abdominal circumference in the spring compared to the fall semester.CONCLUSION: Nonmandatory physical training over summer break may significantly decrease a cadets performance on the PFA. Additionally, it appears that even the inclusion of field training for some cadets was not enough to prevent the detraining that took place over summer break.Mackey CS, Johnson Q, Dawes JJ, DeFreitas JM. Physical performance among Air Force ROTC cadets following non-mandatory training. Aerosp Med Hum Perform. 2020; 91(10):818823.

Exercise Behavior and Mood during the COVID-19 Pandemic in Taiwan: Lessons for the Future

The Coronavirus disease 2019 (COVID-19) pandemic and its associated governmental recommendations and restrictions have influenced many aspects of human life, including exercise and mental health. This study aims to explore the influence of COVID-19 on exercise behavior and its impact on mood states, as well as predict changes in exercise behavior during a similar future pandemic in Taiwan. A cross-sectional online survey was conducted between 7 April and 13 May 2020 (n = 1114). Data on exercise behavior pre and during the pandemic and mood states were collected. A cumulative link model was used to predict changes in exercise frequency during a similar future pandemic by exercise frequency during the pandemic. A linear model was used to predict the influence of exercise frequency before and during the pandemic on mood states during the pandemic. A total of 71.2%, 67.3%, and 58.3% of respondents maintained their exercise intensity, frequency, and duration, respectively, during the pandemic. Frequent exercisers are more likely to maintain their exercise frequency during a similar pandemic (p < 0.001). Higher exercise frequencies during the pandemic were associated with better mood states (p < 0.05). Moreover, the effects of prepandemic exercise frequency on mood states are moderated by changes in exercise frequency during the pandemic (p < 0.05). Additionally, maintenance of exercise frequency during a pandemic specifically for frequent exercisers are recommended to preserve mood states. These results may provide evidence for health policies on exercise promotion and mental health before and during a future pandemic.

Effects of Including Sprints in One Weekly Low-Intensity Training Session During the Transition Period of Elite Cyclists

The purpose of this study was to investigate the effects of including 30-s sprints in one weekly low-intensity training (LIT) session during a 3-week transition period in elite cyclists. Sixteen male elite cyclists (maximal oxygen uptake, VO_2max: 72 ± 5 ml·kg^-1·min^-1) reduced their training load by ~60% for 3 weeks from the end of competitive season and performed only LIT or included 30-s sprints (SPR) in one weekly LIT-session. Performance and physiological capacities were evaluated during a prolonged (~2.5 h) test-session, including a strength test, a submaximal blood lactate profile test, an incremental test to exhaustion to determine VO_2max, 1 h continuous cycling including four maximal 30-s sprints, and a 20-min all-out test. In addition, mental recovery was evaluated using the Athlete Burnout Questionnaire (ARQ). The only significant between-group change during the transition period was an 8 ± 11% larger improvement in 30-s sprint performance in SPR compared to control (CON; SPR: 4 ± 5%, CON: -4 ± 5%, p = 0.01). Although not different from CON, SPR maintained 20-min all-out performance (-1 ± 5%, p = 0.37) and fractional utilization of VO_2max (1.9 ± 6.1%-points, p = 0.18) during the 20-min all-out test, whereas corresponding declines were observed in CON (-3 ± 5%, p = 0.04, and -2.5 ± 2.9%-points, p = 0.02, respectively). Power output at 4 mmol·L^-1 blood lactate concentration decreased similarly in SPR (-4 ± 4%, p = 0.02) and CON (-5 ± 5%, p = 0.01), while VO_2max, maximal aerobic power (W_max), and total burnout score were unaffected in both groups. Including sprints in one weekly LIT-session in the transition period improves sprint performance and maintains 20-min all-out power and fractional utilization of VO_2max without compromising mental recovery. Inclusion of sprints in LIT-sessions may therefore be a plausible, time-efficient strategy during short periods of reduced training.

The Impact of Covid-19 and the Effect of Psychological Factors on Training Conditions of Handball Players

The spread of COVID-19 has altered sport in Spain, forcing athletes to train at home. The objectives of the study were: (i) to compare training and recovery conditions before and during the isolation period in handball players according to gender and competitive level, and (ii) to analyse the impact of psychological factors during the isolation period. A total of 187 participants (66 women and 121 men) answered a Google Forms questionnaire about demographics, training, moods, emotional intelligence, and resilience sent using the snowball sampling technique. T-test and analysis of variance (ANOVA) were used to compare sport level and gender differences. Linear regressions were used to analyse the psychological influence on training. Handball players reduced training intensity (in the whole sample; p = 0.44), training volume (especially in professional female handball players; p < 0.001), and sleep quality (especially in professional male handball players; p = 0.21) and increased sleep hours (especially in non-professional female players; p = 0.006) during the isolation period. Furthermore, psychological factors affected all evaluated training and recovery conditions during the quarantine, except for sleep quantity. Mood, emotional intelligence, and resilience have an influence on physical activity levels and recovery conditions. In addition, training components were modified under isolation conditions at p < 0.001. We conclude that the COVID-19 isolation period caused reductions in training volume and intensity and decreased sleep quality. Furthermore, psychological components have a significant impact on training and recovery conditions.

Effects of 12 months of detraining on health-related quality of life in patients receiving hemodialysis therapy

PURPOSE

Limited data exist regarding the effects of detraining on functional capacity and quality of life (QoL) in the hemodialysis population. The aim of the current study was to assess whether the discontinuation from a systematic intradialytic exercise training program will affect aspects of health-related QoL and functional capacity in hemodialysis patients.

METHODS

Seventeen hemodialysis patients (12 Males/5 Females, age 60.8 ± 13.6 year) participated in this study. Patients were assessed for functional capacity using various functional capacity tests while QoL, daily sleepiness, sleep quality, depression and fatigue were assessed using validated questionnaires at the end of a 12-month aerobic exercise program and after 12 months of detraining.

RESULTS

The detraining significantly reduced patients' QoL score by 20% (P = 0.01). More affected were aspects related to the physical component summary of the QoL (P < 0.001) rather than those related to the mental one (P = 0.096). In addition, the performance in the functional capacity tests was reduced (P < 0.05), while sleep quality (P = 0.020) and daily sleepiness scores (P = 0.006) were significantly worse after the detraining period. Depressive symptoms (P = 0.214) and the level of fatigue (P = 0.163) did not change significantly.

CONCLUSIONS

Detraining has a detrimental effect in patients' QoL, functional capacity and sleep quality. The affected physical health contributed significantly to the lower QoL score. It is crucial for the chronic disease patients, even during emergencies such as lockdowns and restrictions in activities to maintain a minimum level of activity to preserve some of the acquired benefits and maintain their health status.

The influence of a soccer season on non-contact injury and isokinetic peak torque of the quadriceps and hamstrings in professional youth soccer players

Isokinetic strength screening is utilized in professional soccer. However, there has been little research on the interaction between seasonal changes in players' peak torque (PT) and injury incidence. Twenty-five (age 16.5±0.68 years) professional youth soccer players participated in the study. Bilateral isokinetic concentric (CON) and eccentric (ECC) testing of Quadriceps (Q) and Hamstrings (H) were conducted at three time-points across the season. Absolute CON and ECC PT were measured at 60 degree/sec and in a supine 170-degree position. Testing data was normalized to body mass. A mixed design (2 by 3) repeated measures ANOVA with injury as a co-variate was conducted to evaluate the effect of season and/or limb dominance on PT and injury incidence. With regard to the seasonal variation and injury incidence, an interaction was identified with respect to non-dominant limb (NDL) QCON (p = 0.01) and to a lesser extent the dominant limb (DL) QCON (p = 0.05). The seasonal variation of the PT of the NDL QCON was different between the injured and non-injured individuals. Non-injured individuals, QCON strength increased over the course of the season. While for the Injured players, QCON declined from pre-season to mid-season then increased but never recovered to starting pre-season values.

Season Suspension and Summer Extension: Unique Opportunity for Professional Team-Sport Athletes and Support Staff During and Following the COVID-19 Crisis

Given the emergence of the COVID-19 outbreak, the official declaration of a global pandemic by the World Health Organization, and its consequential disruptions on the professional team sports landscape, it is the main objective of this brief opinion to help ensure that professional team-sport athletes and support staff remain aware as a society of some of the potential pitfalls - illustrated via negative but plausible detrimental scenarios. Finally, new ideas are introduced and evidence-based hypotheses are presented on the following five themes: periodization, exploration, virtual (at-home) training, player monitoring, and continued education, including return-to-competition preparation strategies following these exceptional times of uncharted territory.

What Keeps Them Going, and What Gets Them Back? Older Adults’ Beliefs About Physical Activity Maintenance

Background and Objectives

The overall purpose of this article was to investigate beliefs related to physical activity maintenance among adults aged 60 years or older.

Research Design and Methods

Study 1 identified modal, salient behavioral, normative, and control beliefs using a free-response format. Study 2 was designed to gain a deeper understanding about these beliefs through in-depth semistructured interviews.

Results

Findings indicate that perceived physical and emotional benefits, scheduling and having a physical activity routine, social support, and features of indoor and outdoor locations are facilitating of maintenance. Some beliefs appear more relevant to sustained engagement in physical activity, while others may be more helpful for reengagement after 1 week of inactivity.

Discussion and Implications

This investigation raises new hypotheses for future research and provides insight for the use and adaptation of behavior change strategies that are potentially more acceptable and effective for the promotion of physical activity maintenance for older adults.

Effects of strength training under hypoxic conditions on muscle performance, body composition and haematological variables

The addition of a hypoxic stimulus during resistance training is suggested to increase the metabolic responses, enhancing hypertrophy and muscle strength. The purpose of this study was to investigate the effects of resistance training performed at submaximal intensities combined with normobaric hypoxia on muscular performance, body composition and haematological parameters. Thirty-two untrained subjects participated in this study (weight: 74.68±12.89 kg; height: 175±0.08 cm; BMI: 24.28±3.80 kg/m²). They were randomized to two groups: hypoxia (FiO₂ = 13%) or normoxia (FiO₂ = 20.9%). The training programme lasted 7 weeks (3 d/w) and several muscle groups were exercised (3 sets x 65−80% 1RM to failure). Measurements were taken before, after the training and after a 3-week detraining period. Body composition and muscle mass were assessed through skinfolds and muscle girths. Muscle strength was evaluated by the 1RM estimated test. Finally, haemoglobin and haematocrit were taken from the antecubital vein. Both groups improved their strength performance and muscle perimeters, but the hypoxia group obtained a greater increase in muscle mass (hypoxia: +1.80% vs. normoxia: +0.38%; p<0.05) and decrease in fat mass (hypoxia: -6.83% vs. normoxia: +1.26%; p<0.05) compared to the normoxia group. Additionally, haematocrit values were also higher for the hypoxia group after the detraining period (hypoxia: +2.20% vs. normoxia: -2.22%; p<0.05). In conclusion, resistance training under hypoxic conditions could increase muscle mass and decrease fat mass more effectively than training performed in normoxia, but without contributing to greater muscle strength.

Long-Term Effects in the EXERDIET-HTA Study: Supervised Exercise Training vs. Physical Activity Advice

Purpose: To determine whether improvements in cardiorespiratory fitness (CRF), blood pressure (BP) and body composition previously seen after a 16-week exercise intervention (POST) with hypocaloric diet are maintained following six months (6M) of unsupervised exercise time. Methods: Overweight/obese, physically inactive participants with primary hypertension (HTN) (n = 190) were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups. After POST, all participants received diet and physical activity advice for the following 6M but no supervision. All anthropometric and physiological measurements were taken pre and post the 16-week supervised intervention period, as well as after 6M of no supervision. Results: After 6M: 1) body mass (BM) (Δ = 2.5%) and waist circumference (Δ = 1.8%) were higher (P < .005) than POST, but lower (P < .005) than pre-intervention (BM, Δ = -5.1%; waist circumference, Δ = -4.7%), with high-volume and high-intensity interval training group revealing a higher BM reduction (Δ = -6.4 kg) compared to control group (Δ = -3.5 kg); 2) BP variables were higher (P < .001) compared to POST with no change from pre-intervention; and 3) CRF was higher compared to pre-intervention (Δ = 17.1%, P < .001) but lower than POST (Δ = -5.7%, P < .001). Conclusions: When an overweight/obese population with HTN attains significant improvements in cardiometabolic health POST intervention with diet restriction, there is a significant reduction following 6M when exercise and diet supervision is removed, and only recommendations were applied. These results suggest the need for a regular, systematic and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.

Elite Athletes and COVID-19 Lockdown: Future Health Concerns for an Entire Sector

In this editorial, we focused our attention on elite athletes during the COVID-19 lockdown. A high level of physical fitness is required by elite athletes irrespective of the specific type of sport. Generally speaking, elite athletes avoid long periods of rest during and at the end of the competitive season. Normally, elite athletes stop training or reduce training volume and intensity for a period that ranges from two weeks to a maximum of four weeks.

Exercise and physical activity in cirrhosis: opportunities or perils

Reduced exercise capacity and impaired physical performance are observed in nearly all patients with liver cirrhosis. Physical activity and exercise are physiological anabolic stimuli that can reverse dysregulated protein homeostasis or proteostasis and potentially increase muscle mass and contractile function in healthy subjects. Cirrhosis is a state of anabolic resistance, and unlike the beneficial responses to exercise reported in physiological states, there are few systematic studies evaluating the response to exercise in cirrhosis. Hyperammonemia is a mediator of the liver-muscle axis with net skeletal muscle ammonia uptake in cirrhosis causing signaling perturbations, mitochondrial dysfunction with decreased ATP content, modifications of contractile proteins, and impaired ribosomal function, all of which contribute to anabolic resistance in cirrhosis and have the potential to impair the beneficial responses to exercise. English language-publications in peer-reviewed journals that specifically evaluated the impact of exercise in cirrhosis were reviewed. Most studies evaluated responses to endurance exercise, and readouts included peak or maximum oxygen utilization, grip strength, and functional capacity. Endurance exercise for up to 12 wk is clinically tolerated in well-compensated cirrhosis. Data on the safety of resistance exercise are conflicting. Nutritional supplements enhance the benefits of exercise in healthy subjects but have not been evaluated in cirrhosis. Whether the beneficial physiological responses with endurance exercise and increase in muscle mass with resistance exercise that occur in healthy subjects also occur in cirrhotics is not known. Specific organ-system responses, changes in body composition, or improved long-term clinical outcomes with exercise in cirrhosis need evaluation.