Stretching exercises to increase the range of motion (ROM) of joints have been used by sports coaches and medical professionals for improving performance and rehabilitation. The ability of connective and muscular tissues to change their architecture in response to stretching is important for their proper function, repair, and performance. Given the dearth of relevant data in the literature, this review examined two key elements of stretching: stretch intensity and stretch position; and their significance to ROM, delayed onset muscle soreness (DOMS), and inflammation in different populations. A search of three databases, Pub-Med, Google Scholar, and Cochrane Reviews, identified 152 articles, which were subsequently categorized into four groups: athletes (24), clinical (29), elderly (12), and general population (87). The use of different populations facilitated a wider examination of the stretching components and their effects. All 152 articles incorporated information regarding duration, frequency and stretch position, whereas only 79 referred to the intensity of stretching and 22 of these 79 studies were deemed high quality. It appears that the intensity of stretching is relatively under-researched, and the importance of body position and its influence on stretch intensity, is largely unknown. In conclusion, this review has highlighted areas for future research, including stretch intensity and position and their effect on musculo-tendinous tissue, in relation to the sensation of pain, delayed onset muscle soreness, inflammation, as well as muscle health and performance.

Effects of passive static stretching intensity on recovery from unaccustomed eccentric exercise of right knee extensors was investigated in 30 recreationally active males randomly allocated into 3 groups: high-intensity (70%-80% maximum perceived stretch), low-intensity (30%-40% maximum perceived stretch), and control. Both stretching groups performed 3 sets of passive static stretching exercises of 60 s each for hamstrings, hip flexors, and quadriceps, over 3 consecutive days, post-unaccustomed eccentric exercise. Muscle function (eccentric and isometric peak torque) and blood biomarkers (creatine kinase and C-reactive protein) were measured before (baseline) and after (24, 48, and 72 h) unaccustomed eccentric exercise. Perceived muscle soreness scores were collected immediately (time 0), and after 24, 48, and 72 h postexercise. Statistical time × condition interactions observed only for eccentric peak torque (p = 0.008). Magnitude-based inference analyses revealed low-intensity stretching had most likely, very likely, or likely beneficial effects on perceived muscle soreness (48-72 h and 0-72 h) and eccentric peak torque (baseline-24 h and baseline-72 h), compared with high-intensity stretching. Compared with control, low-intensity stretching had very likely or likely beneficial effects on perceived muscle soreness (0-24 h and 0-72 h), eccentric peak torque (baseline-48 h and baseline-72 h), and isometric peak torque (baseline-72 h). High-intensity stretching had likely beneficial effects on eccentric peak torque (baseline-48 h), but likely had harmful effects on eccentric peak torque (baseline-24 h) and creatine kinase (baseline-48 h and baseline-72 h), compared with control. Therefore, low-intensity stretching is likely to result in small-to-moderate beneficial effects on perceived muscle soreness and recovery of muscle function post-unaccustomed eccentric exercise, but not markers of muscle damage and inflammation, compared with high-intensity or no stretching.

Athletes who merit the title ‘elite’ are rare and differ both quantitatively and qualitatively from athletes of lower qualifications. Serving and studying elite athletes may demand non-traditional approaches. Research involving elite athletes suffers because of the typical nomothetic requirements for large sample sizes and other statistical assumptions that do not apply to this population. Ideographic research uses single-athlete study designs, trend analyses, and statistical process control. Single-athlete designs seek to measure differences in repeated measurements under prescribed conditions, and trend analyses may permit systematic monitoring and prediction of future outcomes. Statistical process control uses control charting and other methods from management systems to assess and modify training processes in near real-time. These methods bring assessment and process control into the real world of elite athletics.

Kalaycioglu, T, Apostolopoulos, NC, Goldere, S, Duger, T, and Baltaci, G. Effect of a core stabilization training program on performance of ballet and modern dancers. J Strength Cond Res 34(4): 1166–1175, 2020—The aim of this study was to investigate the effects of a core stabilization training (CST) program on performance of university-level ballet and modern dancers. Twenty-four dancers between the ages of 18 and 24 years participated in the study. Core stabilization training was performed for 45–60 minutes per day, 3 days a week, for 8 weeks. For 2 days, the training was conducted by an experienced physiotherapist, and the other day, each participant exercised on his or her own. Evaluation of physical fitness parameters included vertical jump performance, flexibility, dynamic balance, coordination, proprioception, muscle, and hip flexion isokinetic strength measures. Wilcoxon signed rank test was used to compare pre- and post-test values. Statistically significant increases in vertical jump performance, dynamic balance, proprioception, and coordination parameters between pre- and post-training (p < 0.05) were observed. After the CST program, peak torque values for the hip flexor muscle isokinetic test of the dancers decreased (p < 0.05). Therefore, the results suggest that the CST program might be used to improve several physical fitness parameters such as jumping, proprioception, coordination, and dynamic balance. Such improvements will aid in the development of artistic skills for university modern dancers.

ATHLETE TRAINING SHOULD PROCEED FROM THOROUGH AND SYSTEMATIC PERIODIZED PLANS FOR THE IMPLEMENTATION OF TRAINING LOADS. THE TIME-COURSE OF TRAINING SHOULD INCLUDE PERIODS OF HIGH LOADS PUNCTUATED BY REDUCED LOADS AND REST. AS THERE ARE A WIDE VARIETY OF MEANS AND METHODS USED FOR THE IMPLEMENTATION OF LOADS, THERE ARE NUMEROUS MEANS AND METHODS FOR ENHANCING RECOVERY AND ADAPTATION (RA). RA FROM ATHLETE TRAINING ARE POORLY UNDERSTOOD AND IN NEED OF A MODEL OR FRAMEWORK TO ADVANCE OUR ABILITY TO SYSTEMATICALLY COMPLEMENT TRAINING WITH APPROPRIATE MODALITIES.