Including the Eccentric Phase in Resistance Training to Counteract the Effects of Detraining in Women: A Randomized Controlled Trial.

ABSTRACT: Coratella, G, Beato, M, Bertinato, L, Milanese, C, Venturelli, M, and Schena, F. Including the eccentric phase in resistance training to counteract the effects of detraining in women: a randomized controlled trial. J Strength Cond Res 36(11): 3023-3031, 2022-The current study compared the effects of concentric-based (CONC), eccentric-based (ECC), and traditional concentric-eccentric (TRAD) resistance training on muscle strength, mass, and architecture and the postdetraining retention of the training-induced effects in women. Sixty women were randomly assigned to unilateral volume-equated CONC, ECC, or TRAD knee extension training or control ( N = 15 per group). Before training, after an 8-week intervention period, and after an 8-week detraining period, isokinetic concentric, eccentric, and isometric torque were measured. In addition, thigh lean mass was assessed by dual X-ray absorptiometry and vastus lateralis thickness, pennation angle, and fascicle length by ultrasound. After training, concentric and isometric torque increased ( p < 0.05) similarly in all groups, whereas eccentric torque increased more in ECC than that in CONC (+13.1%, effect size (ES): 0.71 [0.04-1.38]) and TRAD (+12.6%, ES: 0.60 [0.12-1.08]). Thigh lean mass increased in ECC (+6.1%, ES: 0.47 [0.27-0.67]) and TRAD (+3.1%, ES: 0.33 [0.01-0.65]). Vastus lateralis thickness and pennation angle increased ( p < 0.05) similarly in all groups, whereas fascicle elongation was visible in ECC (+9.7%, ES: 0.92 [0.14-1.65]) and TRAD (+7.1%, ES: 0.64 [0.03-1.25]). After detraining, all groups retained ( p < 0.05) similar concentric torque. ECC and TRAD preserved eccentric torque ( p < 0.05), but ECC more than TRAD (+17.9%, ES: 0.61 [0.21-1.21]). All groups preserved isometric torque ( p < 0.05), but ECC more than CONC (+14.2%, ES: 0.71 [0.04-1.38]) and TRAD (+13.8%, ES: 0.65 [0.10-1.20]). Thigh lean mass and vastus lateralis fascicle length were retained only in ECC ( p < 0.05), pennation angle was preserved in all groups ( p < 0.05), and thickness was retained in CONC and ECC ( p < 0.05). Including the eccentric phase in resistance training is essential to preserve adaptations after detraining.

Fast or slow start? The role of running strategies in triathlon.

OBJECTIVES: To investigate the impact of fast-start, steady or slow-start strategies of the running fraction in sprint triathlon on oxygen consumption, perception of fatigue and blood lactate. DESIGN: Thirteen male triathletes (age; 36.4 ±â€¯10.8 yy, height 174.8 ±â€¯7.9 cm, body mass 70.6 ±â€¯11.1 kg; V'O2max 62.4 ±â€¯8.9 ml min-1 kg-1; mean ±â€¯SD) attended the laboratory five times in order to complete two incremental tests and three subsequent cycle-run sessions. METHODS: Three experimental randomized sessions with different effort distribution were compared. The intensities of the 1st running kilometer were set at 95%, 100% and 105% of the second ventilatory threshold for slow, continuous and fast start protocol respectively. Measurement of ventilatory variables, blood lactate and ratings of perceived exertion were collected throughout all sessions. RESULTS: A meaningful difference was found between the slow versus fast start protocol in V'O2 (SE = 0.58, P = 0.0005), BLa- (SE = 0.21, P = 0.0097), HR (SE = 1.23, P = 0.0011) and RPE (SE = 2.83, P = 0.0047) values. No differences in-between protocols were found at the end of the running bout whatever the condition. CONCLUSIONS: Differences in physiological parameters were found between protocols during the first kilometer, not at the end of exercise. The fast start appears to be more correct and useful for performance in racing setting and may be used as a strategy without impacting the remaining running bout in ecological setting.

Physique and performance in male sitting volleyball players: implications for classification and training.

Background: This study assessed whether anthropometry, physical fitness and sport-specific sprint performance vary across the three groups of sitting volleyball (SV) athletes (athletes with a disability (VS1), athletes with a minimal disability (VS2) and able-bodied SV athletes (AB)) in order to explore the validity of the current system of classification. This study also investigated how the anthropometric and physical fitness characteristics of athletes relate to their sprint performance. Methods: Thirty-five SV male athletes aged 37.4 ± 10.8 years and practicing SV at a national/international level volunteered for this study. Testing consisted in the evaluation of linear anthropometry, physical fitness (body composition by-means of dual-energy X-ray absorptiometry and upper-body strength) and sprint performance (5-meter sprint tests, agility test and speed and endurance test). Results: Athletes in the three groups differed in fat mass percentage (%FM) which was higher in VS1 versus AB at the sub-total level (+9%), in the arms (+15%) and in the non-impaired leg (+8%) regions. Greater hand span, greater length of the impaired lower leg, lower %FM at both the sub-total and regional level and a higher level of strength in the upper body are all associated with better performances in the considered sprint tests (P < 0.05 for all). These results do not confirm the validity of the current system of classification of athletes adopted in SV. Professionals dealing with SV athletes should include specific exercises aimed at improving whole-body and regional body composition and the strength of the trunk and upper limbs in their training programs.

Enhancing fitness, enjoyment, and physical self-efficacy in primary school children: a DEDIPAC naturalistic study.

BACKGROUND: Physical activity (PA) (e.g., sport, physical education) promotes the psychophysical development of children, enhances health and wellbeing, offers opportunities for enjoyable experiences, and increases self-efficacy. METHODS: In the DEDIPAC framework, we conducted a naturalistic, cross-sectional study to evaluate the effects of a school-based, long-term intervention on fitness (i.e., cardiovascular endurance, muscular strength, flexibility, speed, and finger dexterity), body mass index (BMI), PA levels, sedentary levels, enjoyment, and physical self-efficacy in primary school children. A group of Italian children (41 boys and 39 girls, aged 10-11 years) involved in the project-named "Più Sport @ Scuola" (PS@S)-was compared with a group of children (41 boys and 39 girls) of the same age not involved in the project. RESULTS: After a four-year long attendance to the PS@S project, participants reported higher scores of cardiovascular endurance, muscular strength, enjoyment, and physical self-efficacy compared to children not involved in the project. Correlation analysis results showed that muscular strength scores correlated positively with BMI, PA levels, and enjoyment. Flexibility of the upper body was positively related to physical self-efficacy, and negatively related to speed and BMI. CONCLUSIONS: Findings suggest that the PS@S project enhanced fitness level, enjoyment, and physical self-efficacy of children.

Sympatho-adrenergic activation by endurance exercise: Effect on metanephrines spillover and its role in predicting athlete's performance.

BACKGROUND: The sympatho-adrenergic activation during exercise is implicated in many cardiovascular respiratory and metabolic adaptations which have been thought to partially explain the different levels of performance observed between trained and untrained subjects. To date, no evidence exists about the association between competition performance and markers of "acute stress response". We designed this study to investigate; (i) the acute sympatho-adrenergic activation during endurance exercise in recreational runners by measuring plasma levels of free metanephrine (MN) and normethanephrine (NMN) before and after a half-marathon run; (ii) the association between the metanephrines levels and the running time. METHODS: 26 amateur runners (15 males, 11 females) aged 30 to 63 years were enrolled. The quantification of MN and NMN was performed by LC-MS/MS. Anthropometric ergonomic and routine laboratory data were recorded. Statistical analyses included paired T-test, univariate and multivariate regressions. RESULTS: The post-run values of MN and NMN displayed a nearly 3.5 and 7 fold increase respectively compared to the baseline values (p < 0.0001 for both). NMN pre-run values and pre/post run delta values showed a significant direct and inverse association (p = 0.021 and p = 0.033, respectively) with running performance. No correlations were found for MN values. CONCLUSION: NMN is a reliable marker of sympatho-adrenergic activation by exercise and can predict endurance performance in the individual athlete. Adaptation phenomenon occurring not only in the adrenal medulla might represent the biological mechanism underlying this association. Further studies on sympatho-adrenergic activation, competition performance and training status should contemplate the measurement of these metabolites instead of their unstable precursors.