Maximal lactate steady state (MLSS) refers to the upper limit of blood lactate concentration indicating an equilibrium between lactate production and lactate elimination during constant workload. The aim of the present study was to investigate whether different levels of MLSS may explain different blood lactate concentration (BLC) levels at submaximal workload in the sports events of rowing, cycling, and speed skating. Eleven rowers (mean +/- SD, age 20.1 +/- 1.5 yr, height 188.7 +/- 6.2 cm, weight 82.7 +/- 8.0 kg), 16 cyclists and triathletes (age 23.6 +/- 3.0 yr, height 181.4 +/- 5.6 cm, weight 72.5 +/- 6.2 kg), and 6 speed skaters (age 23.3 +/- 6.6 yr, height 179.5 +/- 7.5 cm, weight 73.2 +/- 5.6 kg) performed an incremental load test to determine maximal workload and several submaximal 30-min constant workloads for MLSS measurement on a rowing ergometer, a cycle ergometer, and on a speed-skating track. Maximal workload was higher (P < or = 0.05) in rowing (416.8 +/- 46.2 W) than in cling (358.6 +/- 34.4 W) and speed skating (383.5 +/- 40.9 W). The level of MLSS differed (P < or = 0.001) in rowing (3.1 +/- 0.5 mmol.l-1), cycling (5.4 +/- 1.0 mmol.l-1), and in speed skating (6.6 +/- 0.9 mmol.l-1). MLSS workload was higher (P < or = 0.05) in rowing (316.2 +/- 29.9 W) and speed skating (300.5 +/- 43.8 W) than in cycling (257.8 +/- 34.6 W). No differences (P > 0.05) in MLSS workload were found between speed skating and rowing. MLSS workload intensity as related to maximal workload was independent (P > 0.05) of the sports event: 76.2% +/- 5.7% in rowing, 71.8% +/- 4.1% in cycling, and 78.1% +/- 4.4% in speed skating. Changes in MLSS do not respond with MLSS workload, the MLSS workload intensity, or with the metabolic profile of the sports event. The observed differences in MLSS and MLSS workload may correspond to the sport-specific mass of working muscle.

Our results suggest that energy demands of tennis matches are significantly influenced by DR. The highest average VO2 of a game of 47.8 mL.kg-1.min-1 may be regarded as a guide to assess endurance capacity required to sustain high-intensity periods of tennis matches compared with average VO2 of 29.1 mL.kg-1.min-1 for the 270 games. Our results suggest that proper conditioning is advisable especially for players who prefer to play from the baseline.

Overarm movements are essential skills in many different sport games; however, the adaptations to different sports are not well understood. The aim of the study was to analyze upper-body kinematics in the team-handball throw, tennis serve, and volleyball spike, and to calculate differences in the proximal-to-distal sequencing and joint movements. Three-dimensional kinematic data were analyzed via the Vicon motion capturing system. The subjects (elite players) were instructed to perform a team-handball jump throw, tennis serve, and volleyball spike with a maximal ball velocity and to hit a specific target. Significant differences (P < 0.05) between the three overarm movements were found in 17 of 24 variables. The order of the proximal-to-distal sequencing was equal in the three analyzed overarm movements. Equal order of the proximal-to-distal sequencing and similar angles in the acceleration phase suggest there is a general motor pattern in overarm movements. However, overarm movements appear to be modifiable in situations such as for throwing or hitting a ball with or without a racket, and due to differences at takeoff (with one or two legs).

In 1992 Conconi et al. (20) presented an indirect and noninvasive method for the determination of anaerobic threshold (AnT) in an incremental field test for runners. This noninvasive method for the determination of anaerobic threshold is dependent on the occurrence of a deflection of the heart rate performance curve (HRPC). The aim of our study was to evaluate the degree and direction of the deflection of the HRPC and the relationship of the heart rate threshold (HRT) to the lactate turn point in a group of 227 healthy young subjects (age: 23 +/- 4 yr). The subjects were divided into three groups by means of second degree polynomial fitting (GI: regular deflection, kHR > 0.1; G II: no deflection, 0 < kHR < 0.1; G II: inverse deflection, k < -0.1). No significant differences between the groups were found in the anthropometric data or in the power output and the blood lactate concentration at both the first (LTP1) and second (LTP2) lactate turn points and at maximum performance (Pmax). Using the method of Conconi et al. (20), 85.9% of the subjects showed a "regular" deflection, 6.2% showed no deflection at all, and 7.9% showed even an inverted deflection of the HRPC. An HRT could be obtained in both G I and G III, and power output at HRT was not significantly different in comparison to that at the LTP2. No HRT could be assessed in G II. The heart rate at HRT and the LTP2 were significantly lower in G III compared with G I. The phenomenon of heart rate break point may be attractive in training regulation, but its application is limited because a heart rate deflection cannot be found even in young subjects in some cases.

The aim of this study was to determine the effects of frequency of verbal encouragement during maximal exercise testing. Twenty-eight participants (12 males, 16 females) aged 20.9 +/- 1.5 years (mean +/- s) performed a maximal exercise test (VO2max) on a treadmill without any verbal encouragement. The participants were matched according to their pre-test VO2max and placed into either a control group or one of three experimental groups. They performed a second exercise test (post-test) 1 week later. During the second test, the control group received no verbal encouragement; the 20 s (20E), 60 s (60E) and 180 s (180E) encouragement groups received verbal encouragement every 20, 60 and 180 s, respectively, beginning with stage 3 of the exercise test. Relative VO2max, exercise time, blood lactate concentration, respiratory exchange ratio (RER) and ratings of perceived exertion (RPE) were not significantly different from the first test to the second test for the control group without verbal encouragement and the 180E group that received infrequent encouragement. Post-test values were significantly higher than pre-test values for the 20E and 60E groups. The post-test values of the 20E group were significantly higher than their pre-test values for relative VO2max (P < 0.001), exercise time (P < 0.0001), blood lactate concentration (P < 0.05), RER (P < 0.01) and RPE (P < 0.0001); this was also the case for the 60E group for relative VO2max (P < 0.01), blood lactate concentration (P < 0.05), RER (P < 0.05) and RPE (P < 0.05). The results suggest that frequent verbal encouragement (every 20 s and 60 s in the present study) leads to significantly greater maximum effort in a treadmill test than when no encouragement is given or when the encouragement is infrequent (i.e. every 180 s).

Our data demonstrate that serum lipid and lipoprotein levels continue to track from childhood into young adulthood. The persistence and clustering of multiple CVD risk factors from childhood to adulthood and the impact of obesity in this regard point to the need for preventive measures aimed at developing healthy lifestyles early in life. Adverse levels of LDL-C in childhood persist over time, progress to adult dyslipidemias, and relate to obesity and hypertension as well. NCEP guidelines which classify CVD risk on the basis of LDL-C level, are helpful in targeting individuals at risk early in life.

The purpose of this study was to evaluate the effects of various modes of training on the time-course of changes in lipoprotein-lipid profiles in the blood, cardiovascular fitness, and body composition after 16 weeks of training and 6 weeks of detraining in young women. A group of 48 sedentary but healthy women [mean age 20.4 (SD 1) years] were matched and randomly placed into a control group (CG, n = 12), an aerobic training group (ATG, n = 12), a resistance training group (RTG, n = 12), or a cross-training group that combined both aerobic and resistance training (XTG, n = 12). The ATG, RTG and XTG trained for 16 weeks and were monitored for changes in blood concentrations of lipoprotein-lipids, cardiovascular fitness, body composition, and dietary composition throughout a 16 week period of training and 6 weeks of detraining. The ATG significantly reduced blood concentrations of triglycerides (TRI) (P < 0.05) and significantly increased blood concentrations of high-density lipoprotein-cholesterol (HDL-C) after 16 weeks of training. The correlation between percentage fat and HDL-C was 0.63 (P < 0.05), which explained 40% of the variation in HDL-C, while the correlation between maximal oxygen uptake (VO2max) and HDL-C was 0.48 (P < 0.05), which explained 23% of the variation in HDL-C. The ATG increased VO2max by 25% (P < 0.001) and decreased percentage body fat by 13% (P < 0.05) after 16 weeks. Each of the alterations in the ATG had disappeared after the 6 week detraining period. The concentration of total cholesterol (TC), TRI, HDL-C and low density lipoprotein-cholesterol in the blood did not change during the study in RTG, XTG and CG. The RTG increased upper and lower body strength by 29% (P < 0.001) and 38%, respectively. The 6 week detraining strength values obtained in RTG were significantly greater than those obtained at baseline. The XTG increased upper and lower body strength by 19% (P < 0.01) and 25% (P < 0.001), respectively. The 6 week detraining strength values obtained in XTG were significantly greater than those obtained at baseline. The RTG, XTG and CG did not demonstrate any significant changes in either VO2max, or body composition during the training and detraining periods. The results of this study suggest that aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in healthy, young women, while resistance training significantly improved upper and lower body strength only.

No abstract