The time course of cross-education during short-term isometric strength training

Summary Proper mastering of a training means seems to be an important determinant of the quality of strength training. Aim of the paper is to examine the differences in strength in relation to squat-performing experience and to offer a way of improving performance by means of increasing the quality of squat technique. Methods 1. Subjects were divided into two groups according to their previous experience with performing squat: a group of inexperienced (n = 9; age: 21.1 years ± 2.37; height: 179.2 cm ± 8.18; weight: 70.0 kg ± 7.38) and experienced (n = 9; age: 24.0 years ± 1.07; height: 182.1 cm ± 4.14; weight: 81.2 kg ± 4.29). We carried out a test of maximal isometric strength in deep squat (ISOmax50°) and a modified diagnostic set (Fitro Force Plate) which consisted of repetitions of heel raised deep squats with a gradually increasing external loading (FmaxBW+(0-100%)). Posture and the body segments of the participants were not corrected during these tests. Mann-Whitney U test (α=0.05) was used to evaluate the data obtained. Results 1. After comparing the differences in the maximal value of force curve in dynamic muscular mode (FmaxBW+(0-100%)) and the maximal isometric force in deep squat (ISOmax50°) between the groups we found significantly bigger differences in the group of experienced when the resistance represented +75 % (Δ 279.0 N) and +100 % of body weight (Δ 332.2 N). Methods 2. Eleven inexperienced subjects (age: 22.1 years ± 1.52; weight: 78.2 kg ± 2.84) completed a short term experiment (with 4 training sessions in weeklong microcycle). The purpose was to practise deep squat without any content of targeted strength development. No control group was included. Initial and final measurements included the rate of force development test (RFD50°,90°,140°, 0-200 ms), the maximal isometric strength test (ISOmax50°,90°,140°) and the diagnostic set for deep squat (Fitro Dyne Premium). Wilcoxon T-test was used for further analyses (α = 0.01; α = 0.05). Results 2. We found statistically significant increments of ISOmax50° (Δ 89.45 N, p < 0.01), ISOmax90° (Δ 45.63 N, p < 0.05), RFD50°(0-200ms) (Δ 0.42 N.ms-1, p < 0.05), RFD90°(0-200ms) (Δ 0.47 N.ms-1, p < 0.05) and mean power output (Pmean) of entire diagnostic set (Δ 38.8 W, p < 0.01). Conclusions. Increases in the difference in variations between the groups starting from the resistance of 50 % of body weight confirms the recommendations of using lower weights for beginners for the purpose of strength development. Based on the results we conclude that a short-term training programme of deep squat practise (without any intention of improving strength performance) has positive effect on selected strength parameters.

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Short-term volume and turgor regulation in yeast

Essays in Biochemistry ◽

10.1042/bse0450147 ◽

2008 ◽

Vol 45 ◽

pp. 147-160 ◽

Cited By ~ 12

Author(s):

Jörg Schaber ◽

Edda Klipp

Keyword(s):

Dynamic Model ◽

Volume Change ◽

Volume Regulation ◽

Time Course ◽

Osmotic Shock ◽

Intracellular Concentration ◽

Short Term ◽

Hydrodynamic Property ◽

Turgor Regulation ◽

Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

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Morphological Changes in the Brain of Acutely Ill and Weight-Recovered Patients with Anorexia Nervosa

Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie ◽

10.1024/1422-4917/a000265 ◽

2014 ◽

Vol 42 (1) ◽

pp. 7-18 ◽

Cited By ~ 56

Author(s):

Jochen Seitz ◽

Katharina Bühren ◽

Georg G. von Polier ◽

Nicole Heussen ◽

Beate Herpertz-Dahlmann ◽

...

Keyword(s):

Anorexia Nervosa ◽

Cognitive Deficits ◽

Time Course ◽

Morphological Changes ◽

Meta Analysis ◽

Short Term ◽

Clinical Prognosis ◽

Qualitative Review ◽

Brain Changes ◽

The Brain

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

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Effects of Two Isometric Strength Training Methods on Jump and Sprint Performances: A Randomized Controlled Trial

Journal of Science in Sport and Exercise ◽

10.1007/s42978-020-00095-w ◽

2021 ◽

Author(s):

Danny Lum ◽

Tiago M. Barbosa ◽

Ranald Joseph ◽

Govindasamy Balasekaran

Keyword(s):

Randomized Controlled Trial ◽

Strength Training ◽

Controlled Trial ◽

Isometric Strength ◽

Training Methods ◽

Randomized Controlled

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Sprint Kayaking Performance Enhancement by Isometric Strength Training Inclusion: A Randomized Controlled Trial

Sports ◽

10.3390/sports9020016 ◽

2021 ◽

Vol 9 (2) ◽

pp. 16

Author(s):

Danny Lum ◽

Tiago M. Barbosa ◽

Govindasamy Balasekaran

Keyword(s):

Strength Training ◽

Bench Press ◽

Performance Enhancement ◽

Controlled Trial ◽

Time Trial ◽

Isometric Strength ◽

Sports Performance ◽

Knee Angle ◽

Randomized Controlled ◽

Main Effect

Performing isometric strength training (IST) can enhance various sports performance. This study compared the effects of including IST on sprint kayaking performance as compared to traditional strength training. Twenty sprint kayaking athletes (age 22 ± 4 year, stature 1.71 ± 0.09 m, body mass 72.0 ± 11.4 kg) performed a 200-m kayak ergometer time trial (200mTT), isometric squat (IsoSqT), isometric bench press (IsoPress) and isometric prone bench pull (IsoPull) during the pre- and post-tests. Athletes were randomly assigned to either traditional strength training (TRAD) or IST group. Both groups performed a similar strength training program twice a week for six weeks. However, half the volume for squat, bench press and prone bench pull were replaced by IsoSqT, IsoPress and IsoPull, respectively, for the IST group. IsoSqT was performed at 90° knee angle, while IsoPress and IsoPull were performed at 90° and 120° elbow angles, respectively. Each isometric contraction was performed with maximum intensity and sustained for three seconds. A significant main time effect was observed for 200mTT (p < 0.001, ƞ2p = 0.68) and all isometric strength measures (p = 0.001–0.032, ƞ2p = 0.24–0.76) except rate of force development at 0–90 ms (RFD90) obtained from IsoSqT120 and IsoPress90. A group main effect was observed in RFD90 obtained from IsoSqT120 and IsoPull120 (p = 0.003–0.004, ƞ2p = 0.37–0.39). Time x Group interaction was observed for 200mTT (p = 0.027, ƞ2p = 0.68), peak force obtained from IsoSqT90, IsoPress90, and IsoPull120 (p = 0.004–0.006, ƞ2p = 0.36–0.38) and RFD90 obtained from IsoSqT120 and IsoPull120 (p = 0.012–0.015, ƞ2p = 0.28–0.30). Inclusion of IST resulted in greater improvement for sprint kayaking and strength performances then TRAD alone.

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In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

Canadian Journal of Botany ◽

10.1139/b72-023 ◽

1972 ◽

Vol 50 (1) ◽

pp. 177-184 ◽

Cited By ~ 10

Author(s):

Johan A. Hellebust ◽

Arne Haug

Keyword(s):

Amino Acids ◽

Time Course ◽

Alginic Acid ◽

Acid Synthesis ◽

Short Term ◽

Fresh Weight Basis ◽

Mannuronic Acid ◽

Guluronic Acid ◽

Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

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Short-Term Treadmill Running as a Model for Studying Cell-Free DNA Kinetics In Vivo

Clinical Chemistry ◽

10.1373/clinchem.2010.158030 ◽

2011 ◽

Vol 57 (4) ◽

pp. 633-636 ◽

Cited By ~ 58

Author(s):

Thomas Beiter ◽

Annunziata Fragasso ◽

Jens Hudemann ◽

Andreas M Nieß ◽

Perikles Simon

Keyword(s):

Time Course ◽

Treadmill Exercise ◽

Plasma Concentrations ◽

High Mobility ◽

Treadmill Running ◽

Short Term ◽

Cell Free Dna ◽

Free Dna ◽

Cross Country

BACKGROUND Increased plasma concentrations of cell-free DNA (cf-DNA) are considered a hallmark of various clinical conditions. Despite intensive research in this field, limited data are available concerning the time course of release and clearance of cf-DNA in vivo. METHODS We extracted cf-DNA from plasma samples taken before and immediately after a 10-km cross-country run, and from samples taken before, immediately after, and 30 min after exhaustive short-term treadmill exercise. The contribution of nuclear (nDNA) and mitochondrial DNA (mtDNA) was measured by quantitative real-time PCR. The incremental treadmill exercise setup was exploited to delineate the precise sequencing and timing of cf-nDNA, lactate, and high-mobility group box 1 protein (HMGB1) release during the exercise and recovery phases. RESULTS Postexercise plasma cf-nDNA concentrations in cross-country and treadmill runners were significantly increased, by 7.6-fold and 9.9-fold, respectively (P < 0.001). cf-nDNA concentrations were not correlated with age, sex, or body mass index. Plasma concentrations of cf-nDNA and HMGB1 in postexercise samples of treadmill runners were significantly correlated (r = 0.84; P = 0.004). cf-mtDNA concentrations were not affected by treadmill exercise. Time-course analyses demonstrated that cf-nDNA is released within minutes after the onset of exercise and is rapidly cleared from the circulation after the cessation of exercise. Nearly congruent kinetics for cf-nDNA, lactate, and HMGB1 were observed during the exercise phase. CONCLUSIONS A single bout of exhaustive short-term treadmill exercise constitutes a versatile model system suitable for addressing basic questions about cf-DNA biology.

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Photosynthesis, translocation, and alginic acid synthesis in Laminaria digitata and Laminaria hyperborea

Canadian Journal of Botany ◽

10.1139/b72-022 ◽

1972 ◽

Vol 50 (1) ◽

pp. 169-176 ◽

Cited By ~ 21

Author(s):

Johan A. Hellebust ◽

Arne Haug

Keyword(s):

Time Course ◽

Alginic Acid ◽

Acid Synthesis ◽

Laminaria Hyperborea ◽

Short Term ◽

Fresh Weight Basis ◽

Mannuronic Acid ◽

Guluronic Acid ◽

Isolated Cortex ◽

Photosynthetic Capacities

New and old tissues of L. digitata blades have very similar photosynthetic capacities on a fresh weight basis. Very little of the photoassimilate goes into alginic acid, or other macromolecular substances in old blade tissues. Less than 1% of the photoassimilated 14C in the old blade portion of a L. digitata blade was translocated to the new blade tissues in a 5-h experiment. In contrast, there is rapid transport of photoassimilate from bark cells to cells of the underlying tissues of L. digitata and L. hyperborea stipe sections. Isolated cortex and medulla tissues of L. digitata stipes have significant photosynthetic capacities, but are probably so strongly shaded by the darkly pigmented bark cells that little photosynthesis can normally occur in these tissues.A larger proportion of the photoassimilated carbon enters alginate in the cortex and medulla than in the bark of L. digitata and L. hyperborea stipes in short-term experiments. The time course for incorporation of photosynthate into alginate in continuous and pulse-labeling experiments indicates the presence of relatively large pools of alginate precursors. A large proportion of the total 14C incorporated into alginate in short-term experiments is found in the "M–M" (mannuronic acid) and "M–G" (alternating mannuronic and guluronic acid) block components.

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Recovery from Adaptation to Moving Gratings

Perception ◽

10.1068/p060719 ◽

1977 ◽

Vol 6 (6) ◽

pp. 719-725 ◽

Cited By ~ 30

Author(s):

Max J Keck ◽

Benjamin Pentz

Keyword(s):

Time Course ◽

Spontaneous Recovery ◽

Motion Aftereffect ◽

Time Decay ◽

Short Term ◽

Test Grating ◽

Test Conditions ◽

Sinusoidal Gratings ◽

Short Term Adaptation

Short-term adaptation to moving sinusoidal gratings results in a motion aftereffect which decays in time. The time decay of the motion aftereffect has been measured psychophysically, and it is found to depend on (i) the spontaneous recovery from the adapted state, and (ii) the contrast of the test grating. We have measured the decays for various test conditions. An extrapolation of the measurements allows us to obtain a decay which represents the time course of the spontaneous recovery of the direction-sensitive mechanisms.

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