Search

Endurance athletes are a population where self-control in the form of following training plans, race plans, and pacing schedules is key to performing successfully. A valid and stable measure of self-control has theoretical and applied value through the ability to identify athletes who might be susceptible to poor self-control. The present study reports the test-retest stability of the Brief Self-Control Scale (BSCS). 132 endurance athletes (18-65 years) completed the 13-item BSCS on two occasions, separated by two weeks. Stability was measured by calculating the test-retest differences for each questionnaire item, with a stable item showing 90% of respondents' test-retest differences within a reference value of [+ or -]1. Analyses revealed seven items to be stable with the question, Q10 = 'I am able to work effectively toward long-term goals', demonstrating greatest stability (96.4%). In contrast, six items showed relatively poor stability with test-retest difference scores ranging from 84.1-89.9%. Chi-square tests of independence revealed no associations with categorical levels of age, gender, sport, and training habits. In the context of the current findings, we argue that the six unstable items do not represent dispositional self-control behavior among endurance athletes. Future researchers are encouraged to assess the stability of individual items rather than favoring a summary statistic, particularly when developing trait measures., Working from an individual-differences perspective, self-control has been shown to predict behavioral outcomes in contexts such as health (Imhoff, Schmidt, & Gerstenberg, 2014; Schroder, Ollis, & Davies, 2013), education (Tangney, [...]

The accuracy of a simple field test, the 3-minute, 30-second endurance capacity test (3'30' ECT), was evaluated in 12 moderately trained athletes. It consisted of 10 3-minute running bouts, separated by 30-second passive recoveries. The first 5 bouts were performed at 75% of maximal aerobic speed (MAS, which was previously determined), and the last 5 were at a self-selected speed. The result of this test is a speed called [V.sub.end], expressed in km x [h.sup.-1] and calculated as the mean speed for the last 5 bouts. The critical velocity (CV) and the individual anaerobic threshold (IAT) were also determined. Another 17 moderately trained athletes then participated in a test-retest procedure to assess the reproducibility of the 3'30' ECT. The results showed that Vend was correlated with all studied parameters (p < 0.05). [V.sub.end] and CV did not differ relative to MAS ([V.sub.end]: 82.8 [+ or -] 3.3% of MAS; CV 82.5 [+ or -] 3.3% of MAS; p > 0.05). The test-retest procedure indicated a coefficient of variation of 1.99 [+ or -] 1.88%. [V.sub.end] is thus an interesting indicator because (a) it is based on a noninvasive single-visit protocol, (b) its application is in the heavy exercise domain, and (c) it is highly reproducible. The 3'30' ECT thus seems to be an adequate test to determine endurance capacity in moderately trained subjects. KEY WORDS running, exercise test, training, blood lactate, exercise domain

The purpose of this study is to examine improvements in cardiorespiratory fitness ([[??]o.sub.2]) after the use of a mixed-intensity interval endurance-training (MI-ET) program in female soccer players, to validate the MI-ET program as an appropriate training regimen to improve cardiorespiratory fitness ([[??]o.sub.2]) in soccer players. 32 female soccer players (average 18.66 [[+ or -]or ] 0.31 years) were recruited from a group of currently conditioning local U-19 and college soccer teams and randomly assigned to participate in an 8-week periodized training program that involved either the MI-ET program or the continuation of a current endurance-training (ET) program. Analysis of variance indicates no differences in [[??]o.sub.2] values within the group of athletes before participating in the exercise program. After the 8 weeks of training, the MI-ET group of athletes had significantly greater average [[??]o.sub.2] values (62.13 [[+ or -]or -] 0.96 ml [O.sub.2] x [kg.sup.-1] x [min sup.-1] vs. 57.27 [[+ or -]or ] 1.59 ml [O.sub.2] x [kg.sup.-1] x [min.sup.-1]), p = 0.015, along with a greater group average of change in [[??]o.sub.2] (12.44 [[+ or -]or -] 0.92 ml [O.sub.2] x [kg.sup.-1] x [min-sup.-1] vs. 7.72 [[+ or -]or -] 0.99 ml [O.sub.2] x [kg.sup.-1] x [min.sup.- 1]), p < 0.001. The MI-ET program is shown to be a valid means to improve aerobic fitness as indicated by the MI-ET group exhibiting significantly greater 402 measures after training. KEY WORDS aerobic training, intermittent endurance exercise, improvement in [[??]o.sub.2]

The purpose of this study was to determine the effects of a running-specific, periodized strength training program (performed over the specific period [8 weeks] of a 16-week macrocycle) on endurance-trained runners' capacity to maintain stride length during running bouts at competitive speeds. Eighteen well-trained middle-distance runners completed the study (personal bests for 1500 and 5000 m of 3 minutes 57 seconds [+ or -] 12 seconds and 15 minutes 24 seconds [+ or -] 36 seconds). They were randomly assigned to each of the following groups (6 per group): periodized strength group, performing a periodized strength training program over the 8-week specific (intervention) period (2 sessions per week); nonperiodized strength group, performing the same strength training exercises as the periodized group over the specific period but with no week-to-week variations; and a control group, performing no strength training at all during the specific period. The percentage of loss in the stride length (cm)/ speed (m*[s.sup-1]) (SLS) ratio was measured by comparing the mean SLS during the first and third (last) group of the total repetitions, respectively, included in each of the interval training sessions performed at race speeds during the competition period that followed the specific period. Significant differences (p < 0.05) were found in mean percentage of SLS loss between the 3 study groups, with the periodized strength group showing no significant SLS change (0.36 [+ or -] 0.95%) and the 2 other groups showing a moderate or high SLS loss (- 1.22 [+ or -] 1.5% and -3.05 [+ or -] 1.2% for the nonperiodized strength and control groups, respectively). In conclusion, periodized, running-specific strength training minimizes the loss of stride length that typically occurs in endurance runners during fatiguing running bouts. KEY WORDS distance running, cardiovasoular fitnes performance enhancement

Stability ball training (SBT) is believed to improve spinal stability (SS) and could reduce the risk of back pain in sedentary individuals. The purpose of this study was to examine the effects of SBT on SS. Twenty sedentary individuals were randomly assigned to either an experimental group that performed SBT twice per week for 10 weeks or to a control group. Differences between groups were assessed by analysis of variance (ANOVA) with repeated measures. The experimental group improved significantly (p < 0.05) on the static back-endurance test from pretest (149.3 [+ or -] 72.3 seconds) to posttest (194.6 [+ or -] 56.7 seconds) and the side bridge test from pretest (45.4 [+ or -] 39.4 seconds) to posttest (71.3 [+ or -] 59.7 seconds). Back endurance for the control group did not change from pretest (123.4 [+ or -] 64.9 seconds) to posttest (87.5 [+ or -] 40.2 seconds), nor did the results of the side bridge test change for this group from pretest (41.8 [+ or -] 26.4 seconds) to posttest (51.6 [+ or -] 35.9 seconds). These findings illustrate that SBT may provide improvements in SS within this population. Practitioners might use SBT exercises where the position of the spine is maintained during the early phases of back-pain prevention programs. This type of programming might be beneficial to individuals who spend a good deal of time sitting (i.e., in corporate fitness programs) or for individuals who are prone to back pain and have been cleared to exercise. Also, the side bridge and static back endurance assessments may be good choices for measuring SS in field settings. KEY WORDS. trunk endurance, stabilization, local muscles, core stability, back pain

Recent evidence suggests that certain soccer drills produce exercise intensities suitable for physical conditioning. However, it remains debatable whether soccer drills can provide a sufficiently unified exercise intensity among different players and on repetition of a drill, because movement patterns cannot be externally controlled during soccer drills. Good reliability and low variability of exercise intensity would enable all players to receive an appropriate training stimulus. The purpose of this study was to investigate intersubject variability and intrasubject reliability in exercise intensity during soccer drills. It was hypothesized that soccer drills that involve the highest exercise intensities would demonstrate the lowest intersubject variability and the highest intrasubject reliability. Heart rates of 23 professional soccer players were recorded during a range of soccer training drills. The drills consisted of 2 vs. 2 to 8 vs. 8 normal scoring games and 2 further possession games. Heart rate responses were examined for variability, reliability, and suitability for soccer endurance training. Coefficients of variation across players were less than 3% for all drills. Paired t-tests showed no significant differences in heart rate on repetition of the drills and 95% ratio limits of agreement were 1.8-3.8%. There were no significant correlations between exercise intensity and the statistical measures of variability and reliability. Several drills produced exercise intensities suitable for soccer endurance training with mean heart rate responses ranging from 87-91% HRmax. Soccer drills such as those used in the present study appear to be an adequate substitute for physical training without the ball and thus provide simultaneous skill and fitness training. The increase in training time spent developing technical ability and/or a reduction in total training time required may be useful for soccer teams. KEY WORDS. football, fitness training, team training

Fischer, Christian P., Peter PIomgaard, Anne K. Hansen, Henriette Pilegaard, Bengt Saltin, and Bente Klarlund Pedersen. Endurance training reduces the contraction-induced interleukin-6 mRNA expression in human skeletal muscle. Am J Phvsiol Endocrinol Metab 287: E1189-E1194, 2004. First published August 10, 2004; doi: 10.1152/ajpendo.00206.2004.--Contracting skeletal muscle expresses large amounts of IL-6. Because 1) IL-6 mRNA expression in contracting skeletal muscle is enhanced by low muscle glycogen content, and 2) IL-6 increases lipolysis and oxidation of fatty acids, we hypothesized that regular exercise training, associated with increased levels of resting muscle glycogen and enhanced capacity to oxidize fatty acids, would lead to a less-pronounced increase of skeletal muscle IL-6 mRNA in response to acute exercise. Thus, before and after 10 wk of knee extensor endurance training, skeletal muscle IL-6 mRNA expression was determined in young healthy men (n = 7) in response to 3 h of dynamic knee extensor exercise, using the same relative workload. Maximal power output, time to exhaustion during submaximal exercise, resting muscle glycogen content, and citrate synthase and 3-hydroxyacyl-CoA dehydrogenase enzyme activity were all significantly enhanced by training. IL-6 mRNA expression in resting skeletal muscle did not change in response to training. However, although absolute workload during acute exercise was 44% higher (P < 0.05) alter the training period, skeletal muscle IL-6 mRNA content increased 76-fold (P < 0.05) in response to exercise before the training period, but only 8-fold (P < 0.05, relative to rest and pretraining) in response to exercise after training. Furthermore, the exercise-induced increase of plasma IL-6 (P < 0.05, pre- and posttraining) was not higher after training despite higher absolute work intensity. In conclusion, the magnitude of the exercise-induced IL-6 mRNA expression in contracting human skeletal muscle was markedly reduced by l0 wk of training. cytokines; exercise; glycogen; plasma; skeletal muscle

LKB1 complexed with MO25 and STRAD has been identified as an AMP-activated protein kinase kinase (AMPKK). We measured relative LKB1 protein abundance and AMPKK activity in liver (LV), heart (HT), soleus (SO), red quadriceps (RQ), and white quadriceps (WQ) from sedentary and endurance-trained rats. We examined trained RQ for altered levels of MO25 protein and LKB 1, STRAD, and MO25 mRNA. LKB 1 protein levels normalized to HT ([+ or -] 0.03) were LV (0.50 [+ or -] 0.03), SO (0.28 [+ or -] 0.02), RQ (0.32 [+ or -] 0.01), and WQ (0.12 [+ or -] 0.03). AMPKK activities in nanomoles per gram per minute were HT (79 [+ or -] 6), LV (220 [+ or -] 9), SO (22 [+ or -] 2), RQ (29 [+ or -] 2), and WQ (42 [+ or -] 4). Training increased LKB1 protein in SO, RQ, and WQ (P < 0.05). LKBI protein levels after training (%controls) were SO (158 [+ or -] 17), RQ (316 [+ or -] 17), WQ (191 [+ or -] 27), HT (106 [+ or -] 2), and LV (104 [+ or -] 7). MO25 protein after training (%controls) was 595 [+ or -] 71. Training did not affect AMPKK activity. MO25 but not LKB1 or STRAD mRNA increased with training (P < 0.05). Trained values (%controls) were MO25 (164 [+ or -] 22), LKB1 (120 [+ or -] 16), and STRAD (112 [+ or -] 17). LKB1 protein content strongly correlated (r = 0.93) with citrate synthase activity in skeletal muscle (P < 0.05). In conclusion, endurance training markedly increased skeletal muscle LKB 1 and MO25 protein without increasing AMPKK activity. LKB1 may be playing multiple roles in skeletal muscle adaptation to endurance training. adenosine 5'-monophosphate-activated protein kinase; diabetes; serine-threonine kinase-11 ; Ste20-related adaptor protein

Byline: N. I. Volkov (1), A. N. Volkov (1) Abstract: The main bioenergetic qualities--the alactic anaerobic, glycolytic anaerobic, and aerobic potentials--are the main factors of endurance in athletes. These physiological properties may be estimated by three main parameters: power, capacity, and energy efficiency. The specific expression of endurance in athletes is determined by the ratio between these bioenergetic parameters. It has been found that the aforementioned criteria of endurance are expressed in different forms in the cases of critical modes of muscular activity and considerably affect performance in representatives of cyclic sports. Author Affiliation: (1) Russian State University of Physical Education, Sports, and Tourism, Moscow, Russia Article History: Registration Date: 09/10/2004

Byline: I. V. Men'shikov (1) Abstract: A study was made of the effects of prolonged physical exercise (90 min at a power of 17 kgm min.sup.--1 kg.sup.--1) on plasma free fatty acids (FFAs), blood Ca.sup.2+, oxygen consumption (OC), and body temperature of endurance-trained athletes and untrained subjects. The athletes displayed correlations between afterload plasma FFAs, OC, and changes in blood Ca.sup.2+ during exercise. Blood Ca.sup.2+ was shown to regulate the mobilization of lipids in the blood. Author Affiliation: (1) Udmurt State University, Izhevsk, 426034, Udmurtia, Russia Article History: Registration Date: 09/10/2004

Twenty-six active university students were randomly allocated to resistance (R, n = 9), endurance (E, n = 8), and concurrent resistance and endurance (C, n = 9) training conditions. Training was completed 3 times per week in all conditions, with endurance training preceding resistance training in the C group. Resistance training involved 4 sets of upper- and lower-body exercises with loads of 4-8 repetition maximum (RM). Each endurance training session consisted of five 5-minute bouts of incremental cycle exercise at between 40 and 100% of peak oxygen uptake (V[O.sub.2]peak). Parameters measured prior to and following training included strength (1RM and isometric and isokinetic [1.04, 3.12, 5.20, and 8.67 rad * [s.sup.-1]] strength), V[O.sub.2]peak and Wingate test performance (peak power output [PPO], average power, and relative power decline). Significant improvements in 1RM strength were observed in the R and C groups following training. V[O.sub.2]peak significantly increased in E and C but was significantly reduced in R after training. Effect size (ES) transformations on the other dependent variables suggested that performance changes in the C group were not always similar to changes in the R or E groups. These ES data suggest that statistical power and dependent variable selection are significant issues in enhancing our insights into concurrent training. It may be necessary to assess a range of performance parameters to monitor the relative effectiveness of a particular concurrent training regimen. Key Words: resistance, endurance, training, V[O.sub.2]peak

Effects of zinc depletion on total work and peak force of shoulder and knee flexor and extensor muscles in humans have been studied and it was found that peak force was not affected, but that total work for all but knee flexor muscles declined significantly. Data indicate that acute zinc depletion changes total work capacity of skeletal muscle.

Estimating energy expenditure is a common practice for nutrition and exercise science professionals. Such estimations can be particularly useful to endurance athletes, whose goals usually include achieving and maintaining body [...]

Competitive endurance cycling entails repeated, prolonged, and vigorous exercise. Repeated bouts of prolonged and vigorous exercise have been shown to produce a marked depletion in muscle glycogen stores in endurance [...]

A followed prolonged exercise resynthesis of muscle glycogen is important for recovery and evidence shows that consuming carbohydrate post exercise can enhance the process. Carbohydrate-protein solutions might accelerate the rate of glycogen storage as well as restoration of exercise capacity after prolonged activity.

The effect of macronutrient composition of pre-exercise meals on exercise metabolism and performance is determined. It was concluded that the consumption of a pre-exercise meal has minor effects on fat oxidation during high-intensity exercise, and no effect on carbohydrate oxidation or TT performance.

The effects of a high-fat/moderate protein (HFMP) diet on submaximal, maximal, and supramaximal performance are examined. It was observed that adaptation to the HFMP diet resulted in maximal oxygen consumption that could be attributed to a reduction in body mass.

A test was designed to measure the effect of variable carbohydrate intake on time to exhaustion, variations in heart rate (HR), respiratory exchange ratio (RER), and rating of perceived exertion (RPE) in female endurance cyclists during an exercise trial. It was found that female endurance cyclists did not experience a difference in time to exhaustion, HR, or RPE with different levels of CHO intake during an endurance trial.

A study was conducted to investigate an influence of creatine ingestion on both the aerobic and anaerobic performance in elite rowers in the course of endurance training. The results showed that, in elite rowers creatine supplementation improved endurance and anaerobic performance, independent of the effect of intensive endurance training.

The effect of fungal carbohydrases (Carbogen TM [C]) consumed with a meal replacement bar (MRB) on glucose metabolism and endurance exercise performance in five male cyclists are studied. Carbogen taken with a MRB increases blood glucose (BG) with an average of 23% during intense exercise.