Reduction In Training Volume Research Articles

Low-Volume Speed Endurance Training with Reduced Volume Improves Short-Term Exercise Performance in Highly Trained Cyclists.

We investigated the effects of low- and high-volume speed endurance training (SET), with a reduced training volume, on sprint ability, short- and long-term exercise capacity, muscle mitochondrial properties, ion transport proteins, and maximal enzyme activity in highly trained athletes. Highly trained male cyclists (maximal oxygen consumption (V̇O 2max ): 68.3 ± 5.0 mL·min -1 ·kg -1 , n = 24) completed 6 wk of either low (SET-L; 6 × 30-s intervals, n = 8) or high (SET-H; 12 × 30-s intervals, n = 8) volume SET twice per week with a 30% reduction in training volume. A control group (CON; n = 8) maintained their training. Exercise performance was evaluated by i) 6-s sprinting, ii) a 4-min time trial, and iii) a 60-min preload at 60% V̇O 2max followed by a 20-min time trial. A biopsy of m. vastus lateralis was collected before and after the training intervention. In SET-L, 4-min time trial performance was improved ( P < 0.05) by 3.8%, with no change in SET-H and CON. Sprint ability, prolonged endurance exercise capacity, V̇O 2max , muscle mitochondrial respiratory capacity, maximal citrate synthase activity, fiber type-specific mitochondrial proteins (complexes I-V), and phosphofructokinase (PFK) content did not change in any of the groups. In SET-H, maximal activity of muscle PFK and abundance of Na + -K + pump-subunit α 1 , α 2 , β 1 , and phospholemman (FXYD1) were 20%, 50%, 19%, 24%, and 42% higher ( P < 0.05), respectively after compared with before the intervention, with no changes in SET-L or CON. Low SET volume combined with a reduced aerobic low- and moderate-intensity training volume does improve short-duration intense exercise performance and maintain sprinting ability, V̇O 2max , endurance exercise performance, and muscle oxidative capacity, whereas, high volume of SET seems necessary to upregulate muscle ion transporter content and maximal PFK activity in highly trained cyclists.

Optimizing performance and mood state in competitive swimmers through tapering strategies.

Tapering is a concept that is of great importance in relation to performance, due of its great effect on the psychological and physical condition of the swimmer. Therefore, the present study aims to investigate the effect of two-week of tapering characterized by a progressive training volume reduction on mood state and swimming performance in competitive swimmers. Twenty-four competitive male swimmers were randomly assigned into two groups. Experimental group (age = 16.9 ± 0.5 years) and control group (16.1 ± 0.4 years). The mood subscales (tension, depression, anger, fatigue, confusion and vigor), total mood disturbance and swimming performance (50-m front crawl) were measured in pre and posttest. Our findings revealed a significant improvement in mood subscales (20.8 to 47.8%), total mood disturbance (14.4%) and in swimming performance (3.5%) after 2 weeks of tapering training. A significant correlation was observed between the total mood disturbance and the 50 m front crawl (r = -0.63) only in the experimental group. It was concluded that a progressive reduction in training volume with a maintain of intensity could improve mood state and swimming performance. In addition, a change in total mood disturbance could affect swimming performance. Swimming coaches are advised to include tapering period according to the standards we mentioned earlier before competitive swimming to improve mental state, which helps the swimmers to overcome the negative influences of overtraining and therefore they can promote sprint-swimming performance.

Knee, Low Back, and Shoulder Problems Among University and Professional Volleyball Players: Playing With Pain.

The knee, low back, and shoulder account for most overuse injuries in volleyball. Previous researchers have used methodology that did not examine the extent of injury burden and effect on performance. To develop a more accurate and complete understanding regarding the weekly prevalence and burden of knee, low back, and shoulder problems within the highest levels of men's volleyball, including the role that preseason complaints, match participation, player position, team, and age have on complaints. Descriptive epidemiology study. Professional volleyball clubs and the National Collegiate Athletic Association Division I program. A total of 75 male volleyball players, representing 4 teams playing in their country's respective premier league (Japan, Qatar, Turkey, and the United States), participated over a 3-season period. Players completed a weekly questionnaire (Oslo Sports Trauma Research Centre Overuse Injury Questionnaire) reporting pain related to their sport and the extent to which knee, low back, and shoulder problems affected participation, training volume, and performance. Problems leading to moderate or severe reductions in training volume or performance or the inability to participate were considered substantial problems. The mean weekly prevalence of knee, low back, and shoulder problems based on 102 player-seasons was 31% (95% CI = 28%, 34%), 21% (95% CI = 18%, 23%), and 19% (95% CI = 18%, 21%), respectively. Most players (93%, 95/102 player-seasons) reported some level of knee (79%, n = 81/102 player-seasons), low back (71%, n = 72/102 player-seasons), or shoulder (67%, n = 68/102 player-seasons) complaints during the season. Most players (58%, n = 59/102 player-seasons) experienced at least 1 episode of substantial problems affecting the knee (33%, n = 34/102 player-seasons), low back (27%, n = 28/102 player-seasons), or shoulder (27%, n = 28/102 player-seasons). Players with preseason complaints had more in-season complaints than teammates without preseason problems (mean weekly prevalence: knee, 42% versus 8%, t49 = -18.726, P < .001; low back, 34% versus 6%, t32 = -12.025, P < .001; shoulder, 38% versus 8%, t30 = -10.650, P < .001). Nearly all included elite male volleyball players experienced knee, low back, or shoulder problems, and most had at least 1 bout that substantially reduced training participation or sport performance. These findings suggest that knee, low back, and shoulder problems result in greater injury burden than previously reported.

Highlighting the effect of reduced training volume on maintaining hormonal adaptations obtained from periodized resistance training in sarcopenic older women

ABSTRACT Background This study investigated the impact of the High Intensity Interval Resistance Training (HIIRT) protocol on hormonal changes in older women. Research design and methods Forty sarcopenic women were divided into an experimental group (EX = 30) and a control group (C = 10). The EX-group was further divided into Maintenance Training 1 (MT1 = 10), Maintenance Training 2 (MT2 = 10), and Detraining (DT = 10). The participants underwent 8 weeks of resistance training, consisting of hypertrophy and strength cycles. Following this, the EX-group had a 4-week period with no exercise or a reduced training volume. Measurements were taken at three time points. Results After 8 weeks, the EX-group showed significant improvements in Insulin Like Growth Factor-1 (IGF-1), Myostatin (MSTN), Follistatin (Fstn), Growth Hormone (GH) and Cortisol (Cort) compared to the control group. During the volume reduction period, there were no significant differences between MT1 and MT2 groups, but both groups saw increases in IGF-1, Fstn, GH, and decreases in MSTN and Cort compared to the DT group. Conclusions These findings suggest that performing at least one training session per week with the HIIRT protocol is crucial for maintaining hormonal adaptations in sarcopenic older women.

Effects of tapering on performance in endurance athletes: A systematic review and meta-analysis.

To assess the responses to taper in endurance athletes using meta-analysis. Systematic searches were conducted in China National Knowledge Infrastructure, PubMed, Web of Science, SPORTDiscus, and EMBASE databases. Standardized mean difference (SMD) and 95% confidence interval (CI) of outcome measures were calculated as effect sizes. 14 studies were included in this meta-analysis. Significant improvements were found between pre- and post-tapering in time-trial (TT) performance (SMD = -0.45; P < 0.05) and time to exhaustion (TTE) performance (SMD = 1.28; P < 0.05). However, There were no improvements in maximal oxygen consumption ([Formula: see text]) and economy of movement (EM) (P > 0.05) between pre- and post-tapering. Further subgroup analysis showed that tapering combined with pre-taper overload training had a more significant effect on TT performance than conventional tapering (P < 0.05). A tapering strategy that reduced training volume by 41-60%, maintained training intensity and frequency, lasted ≤7 days, 8-14 days, or 15-21 days, used a progressive or step taper could significantly improve TT performance (P < 0.05). The tapering applied in conjunction with pre-taper overload training seems to be more conducive to maximize performance gains. Current evidence suggests that a ≤21-day taper, in which training volume is progressively reduced by 41-60% without changing training intensity or frequency, is an effective tapering strategy.

Relationships between Changes in Hematological Adaptations and Exercise Capacity in Olympic Rowers after a Period of Reduced Training Loads.

Endurance performance is positively associated with hematological adaptations; therefore, high total hemoglobin mass and intravascular volumes are commonly observed in high-level endurance athletes. However, it is still unclear whether the fluctuations in exercise capacity that typically occur in endurance athletes during the annual training cycle are directly associated with changes in hematological adaptations, which appear to be relatively stable during this time. To better understand this issue, a study was conducted with 10 Olympic rowers, who followed the same training program. Athletes underwent laboratory testing in the competitive and the general preparation phase of an annual training cycle (a 34% reduction in training volume). This included a graded exercise test on a rowing ergometer (GXT) and blood measurements of hemoglobin concentration (Hb), total hemoglobin mass (tHb-mass), plasma volume (PV), and blood volume (BV). Decreases in maximal values of power relative to body mass (p = 0.028), lactate concentration (p = 0.005), and heart rate (p = 0.017) in the GXT were registered. At the same time, absolute (p = 0.017) and relative (p = 0.005) PV decreased. Changes in PV (rS = 0.842, p = 0.002) and BV (rS = 0.818, p = 0.004), but not in tHb-mass (rS = 0.588, p = 0.074) and Hb (rS = -0.188, p = 0.602), were significantly correlated with changes in maximal power in the GXT. Our results indicate a close relationship between changes in intravascular volumes and maximal exercise capacity after a period of reduced training loads in elite endurance athletes.

"You can't shoot another bullet until you've reloaded the gun": Coaches' perceptions, practices and experiences of deloading in strength and physique sports.

Deloading refers to a purposeful reduction in training demand with the intention of enhancing preparedness for successive training cycles. Whilst deloading is a common training practice in strength and physique sports, little is known about how the necessary reduction in training demand should be accomplished. Therefore, the purpose of this research was to determine current deloading practices in competitive strength and physique sports. Eighteen strength and physique coaches from a range of sports (weightlifting, powerlifting, and bodybuilding) participated in semi-structured interviews to discuss their experiences of deloading. The mean duration of coaching experience at ≥ national standard was 10.9 (SD = 3.9) years. Qualitative content analysis identified Three categories: definitions, rationale, and application. Participants conceptualised deloading as a periodic, intentional cycle of reduced training demand designed to facilitate fatigue management, improve recovery, and assist in overall training progression and readiness. There was no single method of deloading; instead, a reduction in training volume (achieved through a reduction in repetitions per set and number of sets per training session) and intensity of effort (increased proximity to failure and/or reduction in relative load) were the most adapted training variables, along with alterations in exercise selection and configuration. Deloading was typically prescribed for a duration of 5 to 7 days and programmed every 4 to 6 weeks, although periodicity was highly variable. Additional findings highlight the underrepresentation of deloading in the published literature, including a lack of a clear operational definition.

Pandemic-induced Reductions In Training Volume And Performance In Collegiate Swimmers

The COVID-19 pandemic caused significant training disruptions during the 2020-21 season due to lockdowns, quarantines, and strict adherence to COVID-19 protocols. The effect of pandemic-induced disruptions on swim performance remains unclear. PURPOSE: 1) Determine how pandemic training restrictions affected training volume in a National Collegiate Athletic Association Division 2 (NCAA D2) swim team (compared with a non-pandemic year) and 2) Evaluate differences in performance during a pandemic versus a non-pandemic year at the NCAA D2 regional competition. METHODS: Observational, retrospective, data were collected from a single NCAA D2 swim team. Cumulative training volume data (in yards), across a 28-week season, were compared between a pandemic (2020-2021) versus non-pandemic (2019-2020) season. Swimmers were categorized into three groups (Sprinters, Mid-Distance, and Long-Distance) based on training group and volume analyzed via t-tests. Performance times in 25 swimmers who competed in Regional Championships, during both the non-pandemic and pandemic year, were also compared via 1-way ANOVA. Data expressed as means±SD. RESULTS: 26 male and 22 female swimmers commenced the 2020-21 (pandemic) season, with six male (23%) and five females (23%) voluntarily opting out. Three COVID-19 cases were confirmed (2%) by the medical staff with no long-term effects. Significant reductions in total swim volume were verified in Sprinters (32,867 ± 10,135 vs.14,800 ± 7,995yards;p < 0.001), Mid-Distance (26,457 ± 10,692 vs.17,054 ± 9.923yards;p < 0.001), and Long-Distance (37,600 ± 14,430 vs.22,254 ± 14,418yards;p < 0.001) swimmers (non-pandemic vs. pandemic season, respectively). For the 25 swimmers who competed in Regional Championships, in both the pandemic and non-pandemic years, Sprinters swam faster (n = 8;-0.5 ± 0.6secs), while Mid-Distance (n = 10;0.17 ± 2.1secs) and Long-Distance (n = 7;6.0 ± 4.9secs) swimmers swam slower (F = 11.76;p = 0.0003;r2 = 0.52) with the reduced training volume. CONCLUSION: Pandemic-induced stressors contributed to ~1 out of every 4 (~23%) swimmers opting out of the 2020-21 season. The pandemic caused significant reductions in swim training volume, with Sprinters performing better while Long-Distance swimmers performed worse compared with a non-pandemic year.

Role of progression of training volume on intramuscular adaptations in patients with chronic obstructive pulmonary disease.

Introduction: Quadriceps dysfunction is a common systemic manifestation of chronic obstructive pulmonary disease (COPD), for which treatment using resistance training is highly recommended. Even though training volume is suggested to be a key explanatory factor for intramuscular adaptation to resistance training in healthy older adults, knowledge is scarce on the role of progression of training volume for intramuscular adaptations in COPD. Methods: This study was a sub-analysis of a parallel-group randomized controlled trial. Thirteen patients with severe to very severe COPD (median 66 yrs, forced expiratory volume in 1 s 44% predicted) performed 8 weeks of low-load resistance training. In a post hoc analysis, they were divided into two groups according to their training volume progression. Those in whom training volume continued to increase after the first 4 weeks of training outlined the continued progression group (n = 9), while those with limited increase (<5%) or even reduction in training volume after the initial 4 weeks composed the discontinued progression group (n = 4). Fiber-type distribution and oxidative muscle protein levels, i.e., citrate synthase (CS), hydroxyacyl-coenzyme A dehydrogenase (HADH), mitochondrial transcription factor A (TfAM) as well as quadriceps endurance measures (total work from elastic band and isokinetic knee extension tests), were assessed before and after the intervention period. Results: The continued progression group sustained their training volume progression during weeks 5–8 compared to weeks 1–4 (median +25%), while the discontinued progression group did not (median -2%) (p = 0.007 between groups). Compared with baseline values, significant between-group differences in fiber type distribution and TfAM muscle protein levels (range ± 17–62%, p < 0.05) and in individual responses to change in Type I and Type IIa fiber type proportion, CS, HADH, and TfAM muscle protein levels outcomes (median 89 vs. 50%, p = 0.001) were seen in favor of the continued progression group. Moreover, only the continued progression group had a significant increase in HADH muscle protein levels (+24%, p = 0.004), elastic band (+56%, p = 0.004) and isokinetic (+7%, p = 0.004) quadriceps endurance, but the between-group differences did not reach statistical significance (range 14–29%, p = 0.330–1.000). Discussion: The novel findings of the current study were that patients with COPD who had a continued progression of training volume across the 8-weeks intervention had an increased proportion of Type I fibers, and TfAM muscle protein levels and decreased proportion of Type II fibers compared to those that did not continue to progress their training volume after the initial weeks. Additionally, HADH muscle protein levels and quadriceps endurance measurements only improved in the continued progression group, although no significant between-group differences were seen. These findings highlight the importance of continued progression of training volume during resistive training to counteract quadriceps dysfunction within the COPD population. Still, considering the small sample size and the post hoc nature of our analyses, these results should be interpreted cautiously, and further research is necessary.

Effect of intensified training on cognitive function, psychological state & performance in trained cyclists

ABSTRACT Athletes often undertake intensified training loads prior to competition with the goal of functionally overreaching for temporary performance enhancement; however, little is known about the impact of this on cognitive function. The aim of this study was to investigate the effect of intensified training induced fatigue on cognitive function, psychological state and performance in trained cyclists. Twenty-three trained male cyclists were randomly assigned to an intensified training group or a control group for two-weeks, followed by a two-week taper period. At baseline, one-week, two-weeks and post-taper, participants undertook a series of cognitive, performance, mood and recovery-stress assessments. The training intervention significantly increased training volume, load and strain by 108%, 116% and 151% respectively. Peak and mean power output on a maximal test and time trial significantly decreased by 4.8% and 9.4% following the two-week training intervention compared to baseline, in addition to a 169% change in total mood disturbance and significant disruption to recovery-stress balance. No change in any cognitive measure was observed across the study period. Following a two-week taper, performance, mood and well-being measures returned to baseline. Two weeks of intensified training resulted in overreaching as identified by performance and psychological measures. Cognitive function was not sensitive to intensified training promoting caution with its use as a measure for the early identification of overreaching. Highlights Two-weeks of intensified training significantly increased training volume, load and strain eliciting a state of overreaching in trained male cyclists. Intensified training caused deteriorations in physical performance but did not influence cognitive measures. Mood and recovery-stress balance were negatively affected by intensified training but recovered back to baseline following a two-week taper at a reduced training volume. A two-week taper period following two-weeks of intensified training did not result in improved physiological measures, physical performance parameters or mood above initial baseline values highlighting the need for careful consideration over the purpose, desired outcomes and necessity of intensified training on an individualised basis.

Does Wim Hof Method Improve Breathing Economy during Exercise?

(1) Background: Breathing economy during endurance sports plays a major role in performance. Poor breathing economy is mainly characterized by excessive breathing frequency (BF) and low tidal volume (VT) due to shallow breathing. The purpose of this study was to evaluate whether a 4 week intervention based on the Wim Hof breathing method (WHBM) would improve breathing economy during exercise in adolescent runners. (2) Methods: 19 adolescent (16.6 ± 1.53 years) middle- and long-distance runners (11 boys and 8 girls) participated in the study. Participants were randomly divided into experimental (n = 11) and control groups (n = 8). The study was set in the transition period between competitive race seasons and both groups had a similar training program in terms of running volume and intensity over the course of the study. The experimental group performed breathing exercises every day (~20 min/day) for 4 weeks. The control group did not perform any kind of breathing exercise. The breathing exercises consisted of three sets of controlled hyperventilation and consecutive maximum breath holds. Before and after the intervention, participants performed incremental cycle ergometer testing sessions consisting of two minute stages at 1, 2, 3, and 4 W·kg−1 with breath-by-breath metabolic analysis. During the testing sessions, BF, VT, and minute ventilation (VE) were assessed and compared. (3) Results: There were no statistically significant differences (p > 0.05) in BF, VT, or VE between experimental and control groups before or after the intervention. A nonsignificant small-to-large effect for an increase in VE and BF in both groups following the 4 week intervention period was observed, possibly due to a reduction in training volume and intensity owing to the down period between competitive seasons. (4) Conclusions: The 4 week intervention of WHBM did not appear to alter parameters of breathing economy during a maximal graded exercise test in adolescent runners.

Acute Effect of Electromyostimulation Superimposed on Running on Maximal Velocity, Metabolism, and Perceived Exertion.

Simple SummaryElectromyostimulation is the activation of muscles via electrodes placed on the skin, often by wearing a special suit. The application can be passive or active to intensify the training. There are some studies on cycling with superimposed electromyostimulation. However, little is known about its use in running. Therefore, a group of young healthy men performed three treadmill tests in which speed was gradually increased until exhaustion. In one session they ran without electromyostimulation and in two other sessions with superimposed electromyostimulation. Metabolic response, exertion, and maximal performance were examined. Running with electromyostimulation resulted in a lower maximum running speed, was more strenuous, and, in some cases, more metabolically demanding than running without electromyostimulation. Superimposed electromyostimulation is feasible and intensifies running. Normal runners and those with extreme training volumes could benefit from its use.Electromyostimulation has been shown to intensify exercise when superimposed on cycling. However, little is known about the application during running, which might help to prevent injuries linked to high running volumes, as intensification of running allows for a reduction in training volume. Therefore, the purpose of the study was to examine the effects of electromyostimulation superimposed on running. Men who were no younger than 18 and no older than 35 were eligible for inclusion in the study. Exclusion criteria were previous experience with electromyostimulation training, the presence of a contraindication according to the manufacturer, or a contraindication to physical activity. A sample of 22 healthy males with an ordinary performance capability accomplished three similar cardiopulmonary treadmill tests until exhaustion in a crossover study design that included lactate measurements and interrogations of perceived exertion. The first test was conducted without electromyostimulation and was followed in a randomized order by the second and the third test condition with 30 or 85 Hz stimulation, respectively, of the lower body. Superimposed electromyostimulation significantly reduced the maximal achieved velocity (control 15.6 ± 1.1 vs. 30 Hz 15.1 ± 1.2, p = 0.002; vs. 85 Hz 14.9 ± 1.1 km/h, p < 0.001), increased the perceived exertion at 10, 12 and 14 km/h (85 Hz + 0.7, p = 0.036; +0.9, p = 0.007; +1.3, p < 0.001; 30 Hz + 0.7, p = 0.025; +1.0, p = 0.002; +1.2, p < 0.001), and induced a significantly higher oxygen uptake at 8 km/h (85 Hz + 1.1, p = 0.006; 30 Hz + 0.9 mL·min−1·kg−1, p = 0.042), 10 km/h (30 Hz + 0.9 mL·min−1·kg−1, p = 0.032), and 14 km/h (85 Hz + 1.0 mL·min−1·kg−1, p = 0.011). Both electromyostimulation conditions significantly limited the maximal lactate level (30 Hz p = 0.046; 85 Hz p < 0.001) and 85 Hz also the recovery lactate level (p < 0.001). Superimposed electromyostimulation is feasible and intensifies running. Coaches and athletes could benefit from the increased training stimulus by reducing running velocity or volume, by combining endurance and strength training, and also by inducing better adaptations while maintaining the same velocity or volume. Therefore, electromyostimulation superimposed on running could be an interesting training tool for runners.

Effect of the Reduction in Training Volume during the COVID-19 Era on Performance in 100-m and 400-m Freestyle Events in Greek Swimming Championships.

The COVID-19 pandemic had a profound impact on almost all social activities, including sport participation. Swimming training was greatly reduced during the 2019–2020 and 2020–2021 seasons (by four and two months, respectively), which caused athletes and coaches to worry about performance in championships. The present study investigated the impact of COVID-19 lockdowns on the results of Greek swimming championships in the categories of 13 to 18 years of age during 2020 and 2021. Forty-one coaches were interviewed about the training process (satisfaction, duration of the training season, and daily training swimming distance), and the performance of swimmers in national championships over seven seasons (2014–2021) was analyzed. The duration of the training season and the daily swimming distance, as reported by the coaches, were lower during the 2019–2020 and 2020–2021 seasons, compared to the previous five seasons (p < 0.001). The number of swimmers who achieved qualifying times for the national championships during the COVID-19 era were similar to those in previous years. Comparisons of the times in the 100-m and 400-m freestyle events, in both genders, from 2015 through 2021, showed no significant differences except for the 400-m event in males, in which a lower performance was detected in 2021 compared to 2015 (by 2.7%, p = 0.001). In conclusion, two or four months of detraining during the COVID-19 era had a negative impact on the coaches’ evaluation of the training process, but there was no effect on the number of young swimmers who qualified for the national championships and a negligible effect on swimming performance in 100-m and 400-m freestyle events.

Estimating Repetitions in Reserve in Four Commonly Used Resistance Exercises.

Hughes, LJ, Peiffer, JJ, and Scott, B. Estimating repetitions in reserve in four commonly used resistance exercises. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to determine the accuracy and reliability of estimating repetitions in reserve (RIR) across the squat, bench press, overhead press, and prone row exercises, using both free-weight and Smith machine modalities. Twenty-one trained men attended the laboratory on 14 occasions. They were assessed for 1 repetition maximum (1RM) for the squat, bench press, prone row, and overhead press exercises and subsequently completed 6 RIR testing sessions using 65, 75, and 85% 1RM. In these trials, subjects indicated when they reached 2 RIR (i.e., perceive they could only perform 2 more repetitions), before continuing the set to failure. The same process was then replicated using the alternative equipment modality. To determine accuracy of 2-RIR estimates, 1-sample t-tests assessed differences between 2 and the actual number of repetitions completed after subjects indicated they had reached 2 RIR. Intraclass correlation coefficients were used to determine the reliability of test-retest RIR estimated. There were no clear differences in the accuracy or reliability of estimating RIR between free-weight and Smith machine exercises. Load, however, proved an important factor with the highest accuracy associated with RIR estimations performed when using 85%, followed by 75 and 65% 1RM, respectively. When using loads of 75 and 65% 1RM, it was increasingly likely that individuals would underestimate RIR by >1 repetition, which would practically lead to an undesired reduction in training volume. These results highlight that although estimates of 2 RIR may be accurate and reliable in heavy load resistance training (≥85% 1RM), practitioners should be wary of using this measure with lighter loads.

The Association Between Stress and Injury: A Prospective Cohort Study Among 186 First-Year Contemporary Dance Students

The demanding environment that contemporary dance students are exposed to could result in high stress levels, which can influence injury susceptibility. Therefore, this study aims to investigate the association between stress and injuries. In the period between September 2016 and March 2020, four cohorts of first-year dance students (N = 186; mean age 19.21 ± 1.35 years) were followed for one academic year. Each month, general stress was assessed on a 0–100 visual analogous scale. The Oslo Sports Trauma Research Center Questionnaire on Health Problems was used on a monthly basis to monitor injuries. Injuries were defined as “all injuries” (i.e., any physical complaint irrespective of the need for medical attention or time-loss from dance) and “substantial injuries” (i.e., leading to moderate/severe/complete reductions in training volume or performance). Mann–Whitney tests were performed to measure differences in general stress levels between injured and injury-free students, while repeated-measures ANOVA were performed to investigate whether general stress scores increased before and during injury occurrence. The overall average monthly general stress score over all cohorts for all students was 39.81. The monthly general stress scores ranged from 31.75 to 49.16. Overall, injured and substantially injured students reported higher stress scores than injury-free students, with significant differences in 3 out of the 9 months for all injuries (September, October, March, p < 0.05), and in 5 months for substantial injuries (September, October, November, December, April, p < 0.05). Within the 3-month period before and during injury occurrence, a (marginally) significant linear effect of general stress across the time periods was found for all injuries [F(1.87,216.49) = 3.10, p = 0.051] and substantial injuries [F(2,138) = 4.16, p = 0.018]. The results indicate an association between general stress and injuries. Future research should focus on effects of varying stress levels on injury risk using higher sampling frequency, for instance by measuring weekly since stress levels are likely to fluctuate daily. Practically, strategies aiming at stress reduction might have the potential to reduce the burden of dance injuries and may have positive outcomes for dancers, teachers, schools, and companies.

The influence of exercise training volume alterations on the gut microbiome in highly-trained middle-distance runners

ABSTRACT The aim of this study was to determine the influence of training volume alterations on diversity and composition of the gut microbiome in a free-living cohort of middle-distance runners. Fourteen highly-trained middle-distance runners (n = 8 men; O2peak = 70.1 ± 4.3 ml·kg·min−1; n = 6 women, O2peak: 59.0 ± 3.2 ml·kg·min−1) completed three weeks of normal training (NormTr), three weeks of high-volume training (HVolTr; a 10, 20 and 30% increase in training volume during each successive week from NormTr), and a one-week taper (TaperTr; 55% exponential reduction in training volume from HVolTr week three). Faecal samples were collected before and immediately after each training phase to quantify alpha-diversity and composition of the gut microbiome. A three-day diet record was collected during each training phase and a maximal incremental running test was completed after each training phase. Results showed no significant changes in nutritional intake, alpha-diversity, or global microbial composition following HVolTr or TaperTr compared to NormTr (p’s > 0.05). Following HVolTr, there was a significant decrease in Pasterellaceae (p = 0.03), Lachnoclostridium (p = 0.02), Haemophilus (p = 0.03), S. parasagunis (p = 0.02), and H. parainfluenzae (p = 0.03), while R. callidus (p = 0.03) significantly increased. These changes did not return to NormTr levels following TaperTr. This study shows that the alpha-diversity and global composition of the gut microbiome were unaffected by changes in training volume. However, an increase in training volume led to several changes at the lower taxonomy levels that did not return to pre-HVolTr levels following a taper period.

A Comparison of Training With a Velocity Loss Threshold or to Repetition Failure on Upper-Body Strength Development in Professional Australian Footballers.

To compare resistance training using a velocity loss threshold with training to repetition failure on upper-body strength parameters in professional Australian footballers. A total of 26 professional Australian footballers (23.9 [4.2]y, 189.9 [7.8]cm, 88.2 [8.8]kg) tested 1-repetition-maximum strength (FPmax) and mean barbell velocity at 85% of 1-repetition maximum on floor press (FPvel). They were then assigned to 2 training groups: 20% velocity loss threshold training (VL; n = 12, maximum-effort lift velocity) or training to repetition failure (TF; n = 14, self-selected lift velocity). Subjects trained twice per week for 3weeks before being reassessed on FPmax and FPvel. Training volume (total repetitions) was recorded for all training sessions. No differences were present between groups on any pretraining measure. The TF group significantly improved FPmax (105.2-110.9kg, +5.4%), while the VL group did not (107.5-109.2kg, +1.6%) (P > .05). Both groups significantly increased FPvel (0.38-0.46m·s-1, +19.1% and 0.37-0.42m·s-1, +16.7%, respectively) with no between-groups differences evident (P > .05). The TF group performed significantly more training volume (12.2 vs 6.8 repetitions per session, P > .05). Training to repetition failure improved FPmax, while training using a velocity loss threshold of 20% did not. Both groups demonstrated similar improvements in FPvel despite the VL group completing 45% less total training volume than the TF group. The reduction in training volume associated with implementing a 20% velocity loss threshold may negatively impact the development of upper-body maximum strength while still enhancing submaximal movement velocity.

Performance and Health Decrements Associated With Relative Energy Deficiency in Sport for Division I Women Athletes During a Collegiate Cross-Country Season: A Case Series.

The purpose of this case series was to evaluate the presence of low Energy Availability (EA) and its impact on components of Relative Energy Deficiency in Sport (RED-S) in a population of female collegiate runners. Seven female NCAA Division I athletes (age: 22.3 ± 1.5 yrs; height: 169.7 ± 5.7 cm; weight: 58.3 ± 4.1 kg) were tracked from August until February, covering the beginning (Pre XC), end (Post XC) of their competitive cross country season, and beginning of the following track season (Pre Track). The athletes were assessed for female athlete triad (Triad) risk, energy availability, body composition, resting metabolic rate (RMR), nutritional intake, and blood markers (including vitamin D, ferritin, and triiodothyronine (T3)). From Pre XC to Post XC there were no significant differences in body mass, fat free mass or body fat percentage. At Pre XC, mean EA was 31.6 ± 13.3 kcal/kg FFM∙d-1. From Post XC to Pre Track, there was a significant increase in body mass (59.1 ± 5.1 to 60.6 ± 5.7 kg, p<0.001,d=0.27). From Post XC to Pre Track, there was a significant increase in RMR (1466 ± 123.6 to 1614.6 ± 89.1 kcal·d-1, p<0.001,d=2.6). For 25(OH) vitamin D, there was a significant reduction from Pre XC to Post XC (44.1 ± 10.6 vs 39.5 ± 12.2 ng·mL-1, p=0.047,d=-0.4), and a significant increase from Post XC to Pre Track (39.5 ± 12.2 vs. 48.1 ± 10.4 ng·mL-1, p=0.014,d=0.75). For ferritin, there was a trend towards a decrease from Pre XC to Post XC (24.2 ± 13.2 vs. 15.7 ± 8.8 ng·mL-1, p=0.07, d=-0.75), as well as a trend toward an increase from Post XC to Pre Track (15.7 ± 8.8 vs. 34.1 ± 18.0 ng·mL-1, p=0.08, d=1.3). No differences in T3 were observed across time points. Average Triad risk score was 2.3 ± 1.4. Notably, 5 of 7 athletes met criteria for moderate risk. Despite many athletes meeting criteria for low EA and having elevated Triad risk assessment scores, most were able to maintain body mass and RMR. One athlete suffered severe performance decline and a reduced RMR. Surprisingly, she was the only athlete above the recommended value for ferritin. Following increased nutritional intake and reduced training volume, her performance and RMR recovered. Changes in body mass and body composition were not indicative of the presence of other concerns associated with RED-S. This exploratory work serves as a guide for future, larger studies for tracking athletes, using RMR and nutritional biomarkers to assess RED-S.

Periodized versus classic exercise therapy in Multiple Sclerosis: a randomized controlled trial

BackgroundPeriodizing exercise interventions in Multiple Sclerosis (MS) shows good high intensity exercise training adherence. Whether this approach induces comparable training adaptations with respect to exercise capacity, body composition and muscle strength compared to conventional, linear progressive training programs however is not known. MethodsThirty-one persons with MS (all phenotypes, mean EDSS 2.3±1.3) were randomized into a twelve-week periodized (MSPER, n=17) or a classic endurance (MSCLA, n=14) training program. At baseline (PRE), exercise capacity (maximal exercise test, VO2max), body composition (DEXA) and muscle strength (Biodex®) were assessed. Classic, moderate intensity endurance training (60-80% HRmax, 5 training sessions/2w, 60min/session) was performed on a stationary bicycle. Periodized exercise included 4 recurrent 3-week cycles of alternated endurance training (week 1: endurance training as described above), high intense exercise (week 2: 3 sessions/w, 3 × 20s all-out sprints, 10min/session) and recovery weeks (week 3: one sprint session as described above). POST measurements were performed similar to baseline. Total exercise volume of both programs was expressed as total peak-effort training minutes. ResultsFor MSCLA, total exercise volume included 1728 total peak-effort training minutes, whereas MSPER included only 736. Despite this substantially reduced training volume, twelve weeks of periodized training significantly (p<0.05) improved VO2max (+14%, p=0.001), workload (+20%) and time until exhaustion (+25%). Classic training significantly (p<0.05) improved workload (+10%) and time until exhaustion (+17%), but not VO2max (+5%, p=0.131). Pre-post improvements for VO2max were significantly higher in MSPER compared to MSCLA (p=0.046). ConclusionThese data show that despite substantially lower training time (57% less peak-effort training minutes), 12 weeks of periodized exercise training in persons with MS seems to induce larger improvements in parameters of exercise capacity compared to classic endurance training. We therefore recommend to further investigate the effect of training periodization on various functional rehabilitation measures in MS.

A review of literature on benefits of taper phase for main competition of periodization model in endurance athletes

Purpose The aim of this study was to provide athletes and coaches on informations and benefits of a taper through evidence-based scientific studies and literatures in order to optimize an athlete’s top performance for the major competition. Methods Studies and literatures search was conducted using the databases RISS, KISS, SPORTDiscuss. Key words searched: taper AND(competition, OR performance, OR training, OR training). This study were eventually cited by 22 articles for results of this in total 100 articles. Results The training load is remarkably reduced during a taper. With a reduced training load, training intensity should be maintained during the taper. The training load reductions during the taper should be programmed with reducing training volume at 41% to 60% of pretaper training. The reduction of training frequency during a taper means that affect moderately trained athletes and highly trained subjects differently, reducing 30% to 50% of pretaper training and maintaining training frequencies, respectively. Detraining the duration of a taper is not easy. Most athletes is beneficial from a 2-week shorter or longer tapers, depending on their individual profiles of fitness loss, fatigue dissipation, and anxiety. The manipulations of this training program variables usually affect for most athletes and maximal performance gains. Conclusion Training intensity should be maintained during the taper, training volume reductions should be programmed at 41% to 60% of pretaper training. The reduction of training frequency could be reduced 30% to 50% of pretaper training, and most athletes is beneficial from a 2-week shorter or longer tapers. Future researches should be conducted the practical &amp; effectual differences in individual and teamed-based sports after a taper procedure.