The purpose of this study was to compare the concentration of and the time to peak blood lactate following three 90-s cycle ergometer tests--intermittent all-out (Int-A), continuous all-out (Cont-A), and continuous constant (Cont-C), and to compare group peak lactate to blood lactate at individual peak time. Eight fingertip blood samples were drawn between 1 and 12min post-exercise. Subjects were university hockey players (n = 19) and physical education students (n = 19). The two all-out tests had a higher peak concentration than the Cont-C test (P $<$ 0.05). The Int-A test had an earlier peak than the two continuous tests (P $<$ 0.05) but this difference vanished if peak time was measured from the onset of the tests. A number of sampling times had lactate concentrations similar to the individual peak concentration (P $<$ 0.05): (1) 1, 2, 3, and 4min for Int-A; (2) 2, 3, 4, 5, and 6min for Cont-A; (3) 2 and 4min for Cont-C.

The purpose was to compare the blood lactate response and performance of varsity hockey players to recreational players, and to provide a shift by shift analysis of blood lactate accumulation in a simulated ice hockey task. Ten university, varsity players and ten recreational players performed a continuous aerobic treadmill test (VO2max), a 45 s Wingate test, and four trials of the Repeat Sprint Skate (RSS) test. Each RSS test consisted of four repetitions of a 91.4 m skate with repetitions initiated on 30 s intervals. To simulate game, competition, 5 min of recovery separated each RSS test. Results indicated: (1) performance of the varsity players was superior (p < 0.01) to that of the recreational players in the RSS test; (2) four shifts of the RSS test elicited similar peak blood lactate concentrations for the varsity and recreational groups; (3) change in blood lactate following 15 min of passive recovery was similar in the two groups, and (4) there was a significant relationship (&prop; = 0.05) between performance indices in the RSS test and corresponding variables measured in the 45 s Wingate test.

The purpose of this study was to determine if previously observed differences in ratings of perceived exertion (RPE) at the same intensities during two graded exercise tests (GXT) were the result of changes in blood lactate concentrations (BLC). Thirteen healthy males (25.3 ±53 yrs.) were maximally tested during two protocols (Bruce and Balke 3.0 mph/2.5 % grade changes every 2 minutes). Subjects were randomly assigned to one GXT and completed the second test after 48 hours; both were completed within one week. Ratings of perceived exertion (RPE) were recorded at the end of each 2 minute stage of the Balke and twice per stage during the Bruce protocol. Blood lactate concentrations (BLC) were collected each minute during both protocols.Results: RPE data was first analyzed using two-way ANOVA (protocol x intensity), and a significant interaction was observed with RPEs being higher at each intensity during the Balke protocol. Mean RPE differences were 1.4, 2.8, and 4.5 for 40, 60, 80% of VO2max respectively. The addition of the BLC at each relative exercise intensity as a covariate in the model suggested that BLC accounted for some of the protocol differences in RPE, at 60 and 80% of VOimax.Conclusion: Differences in RPEs between standard GXT protocols reported in previous studies were due, in part, to differences in BLC. / School of Physical Education

The purpose of this study was to examine if measurements of submaximal blood lactate may improve the prediction of VO2max from submaximal exercise tests. Subjects (39 men & 21 women, age 20-44 yrs) completed a branching protocol on a cycle ergometer which consisted of 3 submaximal stages of 4 minutes each followed by a maximal effort. During the last minute of each stage heart rate (HR) was recorded from telemetry and a capillary blood sample was obtained from a finger puncture. Maximal power output was estimated from the extrapolation of the 3 submaximal HRs to age predicted HRmax and blood lactate concentration was measured using a Yellow Springs analyzer (Yellow Springs, OH). Data were analyzed using multiple regression procedures. Estimated maximal power output (238 ± 56 W) was significantly related to measured VOzmaX (p < 0.001, r2= .523). Mean values for ACSM estimated, ACSM-revised and measured VOz.X were not significantly different (3.170 vs. 3.140 vs. 3.260 L/min respectively), however the SEE % for the ACSM and ACSM revised estimated VOz,. were 13.4% and 12.1%, respectively. When the change in power output relative to the change in blood lactate concentrations (po/BL) from stage 1 to stage 2 and the estimated maximal power output from 3 submaximal heart rates were added as independent variables to the regression model with measured VO2,t as the dependent variable, po/BL was significantly correlated with VO X , accounting for 7.6% of the variance in VOz... In conclusion, only the relative change in power output to the relative change in blood lactate measure from stage 1 to _2 were significant in improving the estimation of VO2 during submaximal exercise tests using a branching protocol. Other blood lactate measures did not improve the estimation of VOA,. in this study. / School of Physical Education

The purpose of this study was to examine the effects of recovery modes and exercise durations on blood lactate concentrations and subsequent performance in cycling tests. Fourteen male subjects completed six randomly assigned experimental protocols with a combination of three durations and two modes of recovery (passive and active cycling at 45% VO$ sb{ rm 2 max}$). Each protocol consisted of eight bouts of cycling at 120% of VO$ sb{ rm 2 max}$ interspersed with five minute recovery periods. Each protocol terminated with a maximal performance task consisting of a 45s all-out cycling test. Results indicated significantly (p $<$ 0.05) higher blood lactate concentrations in the passive and 60s conditions. Mean power outputs measured in the performance task were significantly (p $<$ 0.05) higher in the active recovery conditions compared to passive recovery. Mean power outputs were lower during the 60s conditions. Since the correlation between blood lactate and mean power output was low (r = -0.24), other factors were influencing subsequent performance.

Blood lactate concentration and mean power output were examined over a series of maximal intermittent exercise bouts with varying recovery patterns. Thirteen elite male cyclists completed four randomly assigned experimental conditions. Each exercise/recovery condition consisted of twelve 10 s maximal exercise bouts on a Monark cycle ergometer. Four different recovery patterns (30, 60, 90 and 120 s) followed the repeated 10 s all-out efforts. Results revealed that the mean power output averaged over the 12 trials was 12.7, 13.0, 13.2 and 13.4 W/kg, for the 30, 60, 90 and 120 s conditions, respectively. Blood lactate concentration during exercise were 9.9, 9.2, 6.5 and 6.0 mmol/1, for the 30, 60, 90 and 120 s conditions, respectively. The 30 and 60 s conditions yielded significantly lower mean power output values compared to the 90 and 120 s conditions. Following the repeated maximal 10 s efforts, blood lactate concentration was significantly greater in the 30 and 60 s recovery conditions compared to the 90 and 120 s conditions.

No description available.

Laboratory-based rowing tests are the established standard for assessing fitness traits among elite rowers, and for prescribing individualised exercise intensities for training. But because tests occur on a rowing ergometer, the specificity of laboratory testing has been questioned compared with the criterion of on-water rowing. This project validated equipment required to replicate a laboratory-based rowing test in the field and evaluated the feasibility of on-water tests. Ergometer and on-water test results were compared to assess the validity of ergometer-derived training prescriptions and to establish the effectiveness of on-water tests for monitoring longitudinal fitness changes and for predicting rowing performance. Concept2 rowing ergometers (Morrisville, USA) have frequently been used for rowing tests. Although subtle design variations exist between the different models of Concept2 ergometer, there were no substantial differences between the results from incremental rowing tests using Model C and Model D ergometers. The Concept2 Model D was therefore accepted as the standard ergometer for subsequent laboratory tests. Typical error (TE) results from duplicate Concept2 Model D tests conducted 2-4 d apart showed that laboratory tests were highly reliable (TE: maximal power = 2.8%, peak oxygen consumption = 2.5%). As oxygen consumption (VO2) is measured routinely during laboratory rowing tests, it is necessary to obtain similar measurements during any on-water protocol. The MetaMax 3B portable indirect calorimetry system (Cortex, Leipzig, Germany) was therefore validated against a first-principles, laboratory-based indirect calorimetry system (MOUSe, Australian Institute of Sport, Canberra, Australia). VO2 from the MetaMax was significantly higher during submaximal exercise (p=0.03), although results were within 0.16 L.min-1 (4.1%) across all exercise intensities. There was good agreement between duplicate MetaMax trials separated by ~2 d; mean VO2 was within 0.11 L.min-1 (2.5%) and TE was ¡Ü2.3%. The specificity of rowing testing was improved using an On-water incremental test that replicated a laboratory-based Ergometer protocol. However, the individual variation in physiological responses between-tests meant that training intensity recommendations from the Ergometer test were not always applicable to on-water training. Furthermore, measurements from the On-water protocol displayed similar or lesser reliability (TE=1.9-19.2%) compared with the Ergometer test (TE=0.1-11.0%). As an effective fitness test must also be sensitive to longitudinal changes, the responses to 6 wks training were compared between the Ergometer and On-water methods. The magnitude of On-water training effects were usually greater (small Cohen¡¯s effect size) compared with the Ergometer test (trivial effect), although On-water and Ergometer tests both indicated that training responses were negligible because virtually all changes were less than one of their respective TEs. Correlations between test results and rowing performance were largest when rowing mode was matched between conditions, but Ergometer results provided the highest correlations (Ergometer vs. 2000-m ergometer time-trial: R= -0.92 to -0.97 compared with On-water vs. On-water maximal power output: R=0.52 to 0.92). Although On-water tests improved the specificity of on-water training prescriptions, these tests provided no obvious benefits for monitoring longitudinal fitness changes or performance compared with Ergometer tests. Given that On-water tests are also more time consuming and logistically challenging, their practical application is limited.

No description available.

No description available.