The Effect of Cold Water Immersion on Physiological Indices, Inflammatory and Immune Responses during a Soccer Match / 대한스포츠의학회지

Purpose@#We investigated the effects of cold water immersion (CWI) treatment during half-time break on performance related physiological indices during second half soccer match. @*Methods@#Twenty-two collegiate soccer players participated in the study. Subjects undertook 3 minutes head out seated with whole body immersion at 19 o C to 21 o C. Total four venous blood samples were collected and analyzed for markers of ionic regulations and inflammatory (interleukin [IL]-1b, IL-6, IL-8, IL-10, tumor necrosis factor-α , and vascular endothelial growth factor) and immune functions (immunoglobulin [Ig] G, IgG2, IgG2, IgG3, IgG4, IgA, and IgM). @*Results@#Partial oxygen concentration and %SO 2 level was lowered in CWI. Hemoglobin and hematocrit values were not significantly different between experimental groups. While there was no notable effect was shown in Na ＋ and Ca 2＋ , K ＋ concentration was higher in CWI during second half match. There were no effects in any of inflammatory and/or anti-inflammatory cytokines and Ig. @*Conclusion@#These results suggest that CWI during half time break exert positively affects in buffering capacity and promote oxygen delivery to the actively recruited skeletal muscle, possibly results in improve soccer performance during second half match.

The Changes of Contraction Patterns in Trunk Muscles with Multidirectional Tilting Motion on the Dynamic Posturography / 대한스포츠의학회지

PURPOSE: The aim of this study was to investigate the changes of contraction patterns and the differences of activities in trunk muscles during dynamic balance (multidirectional tilting exercise). METHODS: Eight physically active male subjects participated in the study. Tilting exercises were included by four directions (i.e., forward, backward, left, and right side), and were undertaken at three different tilting degrees (i.e., 10°, 20°, and 30°). They performed two occasions of tilting exercise, separated by 6-week time interval. Surface electromyography system was used for record of any signals produced by muscles which normalized as percentage of maximum voluntary isometric contraction. RESULTS: There were no statistically significant different interactive effects in any of muscles between two factors (time vs. degree). However, we identified significant main effects of degrees (among 10°, 20°, and 30°) in muscle activations during maintaining with forward tilting (left and right longissimus, multifidus), backward tilting (left and right rectus abdominis, external oblique), left side tilting (right rectus abdominis, external oblique, longissimus, multifidus), right side tilting (left rectus abdominis, external oblique, longissimus, multifidus). CONCLUSION: Findings from this study allow the multidirectional tilting exercise to be considered as suitable for ameliorate muscle balance by inducing co-contraction in trunk muscles.

Effect of Forward and Backward Arm Extension Movement of Pilates Exercise Using Cadillac Instrument on Trunk Muscle Activity / 대한스포츠의학회지

PURPOSE: This study analyzed the muscle activity changes induced by motions of reaching forward and chest expansion that were examined from the bilateral muscles with rectus abdominis, external oblique, multifidus, and longissimus thoracic using Pilates cadillac instrument. METHODS: Nine young adult women, who have no musculoskeletal disorder and any of chronic diseases, were participated. Surface electromyography system was used for recording of all signals produced by muscles, and then normalized as percentage of maximum voluntary isometric contraction (%MVIC). The paired t-test and repeated measures of analysis of variance was performed. RESULTS: Reaching-forward motion showed a higher muscle activity from non-dominant external oblique muscle than that of the chest-expansion motion. During both reaching-forward motion and chest-expansion motion, MVIC values collected from dominant side of external oblique muscle were shown a significantly lower than the values obtained from non-dominant side (p < 0.05). Conversely, %MVIC values in external oblique muscle collected from dominant side showed a significantly higher than the values obtained from non-dominant side of the same oblique muscle (p < 0.05). Reaching-forward motion was caused a higher %MVIC on non-dominant external oblique muscle than that of the chest-expansion motion (p < 0.05). Regardless of dominant or non-dominant sides, external oblique muscle was shown the highest activation rate of all the other muscles during reaching forward action, and longissimus thoracic muscle was shown the highest activation rate of all the other muscles during chest expansion action. CONCLUSION: Reaching-forward motion is suitable for activating an external oblique muscle, and chest-expansion motion is an effective enough in activating of longissimus thoracic muscle.

Body Fat Content Does Not Affect Body's Maximal Muscle Strength / 대한스포츠의학회지

We investigated that the relationship between body fat content and maximal muscle strength when skeletal muscle mass was matched. Muscle mass was measured from 140 preliminary selected people, and 30 males were finally selected and divided into one of four experimental groups: low body fat (group 1, ≤11.9%), low-moderate fat (group 2, 12.0%-16.9%), moderate-high fat (group 3, 17.0%-22.9%), high fat (group 4, ≥23.0%). All subjects undertook one repetition maximum (1RM) test of abdominal and back upper body's and lower body's, and bench press, squat, and back strength dynamometer was used. Repeated oneway analysis of variance and Tukey's post-hoc test was adopted to specify mean differences among groups. Statistical significance level was set at α=0.05. 1RM of bench press was not different among groups (p>0.05) even though values from group 2 was marginally higher (15.9%) than group 1 values (p=0.091). 1RM of squat was higher in group 4 compared to group 2 and group 3 (p<0.05), and maximal back muscular strength was higher in group 1 and group 3 than group 2 (p<0.05). However, total 1RM values, sum of 1RM obtained from different exercises, did not reveal any statistical differences. No notable correlation was found between percent body fat (%BF) and maximal muscular strength. Interestingly, negative correlation of muscular strength was observed between %BF and relative (per kilogram) body mass (p<0.001), but not with between %BF and relative skeletal muscle mass. Therefore, it was concluded that maximal muscular strength is influenced not by fat mass but by skeletal muscle mass.