Search Results

You are looking at 91 - 100 of 691 items for :

  • Physical Education and Coaching x
Clear All
Restricted access

Cory W. Baumann, Jeffrey C. Rupp, Christopher P. Ingalls and J. Andrew Doyle

Purpose:

The purpose of this study was to examine the relationship between anaerobic characteristics and 5-km-race performance in trained female cross-country runners (N = 13).

Methods:

The runners performed 50-m sprints and a 5-km time trial on an outdoor 400-m track and maximal anaerobic (MART) and aerobic running tests on a motorized treadmill. Anaerobic characteristics were determined by the mean velocity of the 50-m sprint (v 50m) and the peak velocity in the MART (v MART). The aerobic characteristics were obtained during the aerobic treadmill test and included maximal oxygen uptake (VO2max), running economy, and ventilatory threshold (VT).

Results:

Both the v MART (r = .69, P < .01) and VO2max (r = .80, P < .01) correlated with the mean velocity of the 5-km (v 5km). A multiple-linear-regression analysis revealed that the combination of VO2max, v MART, and VT explained 81% (R 2 = .81, P < .001) of the variation seen in the v 5km. The v MART accounted for 31% of the total shared variance, while the combination of VO2max and VT explained the remaining 50%.

Conclusions:

These results suggest that among trained female runners who are relatively matched, anaerobic energy production can effectively discriminate the v 5km and explain a significant amount of the variation seen in 5-km-race performance.

Restricted access

Billy Sperlich, Christoph Zinner, David Trenk and Hans-Christer Holmberg

Purpose:

To examine whether a 3-min all-out test can be used to obtain accurate values for the maximal lactate steady state (v MLSS) and/or peak oxygen uptake (VO2peak) of well-trained runners.

Methods:

The 15 male volunteers (25 ± 5 y, 181 ± 6 cm, 76 ± 7 kg, VO2peak 69.3 ± 9.5 mL · kg−1 · min−1) performed a ramp test, a 3-min all-out test, and several submaximal 30-min runs at constant paces of v END (mean velocity during the last 30 s of the 3-min all-out test) itself and v END +0.2, +0.1, –0.1, –0.2, –0.3, or –0.4 m/s.

Results:

v MLSS and v END were correlated (r = .69, P = .004), although v MLSS was lower (mean difference: 0.26 ± 0.32 m/s, 95% CI –.44 to –.08 m/s, P = .007, effect size = 0.65). The VO2peak values derived from the ramp and 3-min all-out tests were not correlated (r = .41, P = .12), with a mean difference of 523 ± 1002 mL (95% CI –31 to 1077 mL).

Conclusion:

A 3-min all-out test does not provide a suitable measure of v MLSS or VO2peak for well-trained runners.

Restricted access

William McGarvey, Richard Jones and Stewart Petersen

The purpose of this investigation was to examine the effect of interval (INT) and continuous (CON) cycle exercise on excess post-exercise oxygen consumption (EPOC). Twelve males first completed a graded exercise test for VO2max and then the two exercise challenges in random order on separate days approximately 1 wk apart. The INT challenge consisted of seven 2 min work intervals at 90% VO2max, each followed by 3 min of relief at 30% VO2max. The CON exercise consisted of 30 to 32 min of continuous cycling at 65% VO2max. Gas exchange and heart rate (HR) were measured for 30 min before, during, and for 2 h post-exercise. Three methods were used to analyze post-exercise oxygen consumption and all produced similar results. There were no significant differences in either the magnitude or duration of EPOC between the CON and INT protocols. HR, however, was higher (P < 0.05) while respiratory exchange ratio (RER) was lower (P < 0.05) following INT. These results indicate that when total work was similar, the magnitude and duration of EPOC were similar following CON or INT exercise. The differences in HR and RER during recovery suggest differential physiological responses to the exercise challenges.

Restricted access

Jasper Reenalda, Maurice T.F. Maas and Jos J. de Koning

Purpose:

To examine the influence of induced changes in the morphology of the leg by adding mass on the optimal step length (OSL) in experienced runners to get more insight into parameters that influence preferred step length (PSL) and OSL.

Methods:

Thirteen experienced male runners (mean age 26.9 ± 6.1 y, height 183.7 ± 7.1 cm, mass 71.8 ± 5.9 kg) ran on a treadmill in 3 different conditions: unloaded (UL), loaded with 2 kg mass at the ankles (MA), and loaded with 2 kg mass at the hips (MH) at 7 different step lengths (SLs). SL deviations were expressed as deviations in relative leg length (%LL) from the individual PSL: 0%LL, ±5%LL, ±10%LL, and ±15%LL. Trials lasted 8 min, and 8 min of rest was given between trials. Oxygen uptake (V̇O2) was expressed as a fraction of V̇O2 at PSL + 0%LL in the unloaded condition (%V̇O2). The %SL with the lowest value of %V̇O2 was considered the OSL for this group of participants.

Results:

OSL at the UL condition was 6% shorter than PSL. The MA condition resulted in a 7%LL larger OSL than at UL and MH (P < .05).

Conclusions:

The mass distribution of the leg is a determinant of the OSL. As a consequence of the added mass to the ankles, OSL was 7%LL longer. Morphological characteristics of the leg might therefore play an important role in determining the runner’s individual optimal SL.

Restricted access

Ville Vesterinen, Ari Nummela, Sami Äyrämö, Tanja Laine, Esa Hynynen, Jussi Mikkola and Keijo Häkkinen

Regular monitoring of adaptation to training is important for optimizing training load and recovery, which is the main factor in successful training.

Purpose:

To investigate the usefulness of a novel submaximal running test (SRT) in field conditions in predicting and tracking changes of endurance performance.

Methods:

Thirty-five endurance-trained men and women (age 20–55 y) completed the 18-wk endurance-training program. A maximal incremental running test was performed at weeks 0, 9, and 18 for determination of maximal oxygen consumption (VO2max) and running speed (RS) at exhaustion (RSpeak) and lactate thresholds (LTs). In addition, the subjects performed weekly a 3-stage SRT including a postexercise heart-rate-recovery (HRR) measurement. The subjects were retrospectively grouped into 4 clusters according to changes in SRT results.

Results:

Large correlations (r = .60–.89) were observed between RS during all stages of SRT and all endurance-performance variables (VO2max, RSpeak, RS at LT2, and RS at LT1). HRR correlated only with VO2max (r = .46). Large relationships were also found between changes in RS during 80% and 90% HRmax stages of SRT and a change of RSpeak (r = .57, r = .79). In addition, the cluster analysis revealed the different trends in RS during 80% and 90% stages during the training between the clusters, which showed different improvements in VO2max and RSpeak.

Conclusions:

The current SRT showed great potential as a practical tool for regular monitoring of individual adaptation to endurance training without time-consuming and expensive laboratory tests.

Restricted access

Amy Warren, Erin J. Howden, Andrew D. Williams, James W. Fell and Nathan A. Johnson

Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat loss. The authors examined the effects of exercise intensity, duration, and modality on postexercise oxygen consumption (VO2) and substrate selection/respiratory-exchange ratio (RER) in healthy individuals. Three experiments (n = 7 for each) compared (a) short- (SD) vs. long-duration (LD) ergometer cycling exercise (30 min vs. 90 min) matched for intensity, (b) low- (LI) vs. high-intensity (HI) cycling (50% vs. 85% of VO2max) matched for energy expenditure, and (c) continuous (CON) vs. interval (INT) cycling matched for energy expenditure and mean intensity. All experiments were administered by crossover design. Altering exercise duration did not affect postexercise VO2 or RER kinetics (p > .05). However, RER was lower and fat oxidation was higher during the postexercise period in LD vs. SD (p < .05). HI vs. LI resulted in a significant increase in total postexercise energy expenditure and fat oxidation (p < .01). Altering exercise modality (CON vs. INT) did not affect postexercise VO2, RER, or fat oxidation (p > .05). These results demonstrate that postexercise energy expenditure and fat oxidation can be augmented by increasing exercise intensity, but these benefits cannot be exploited by undertaking interval exercise (1:2-min work:recovery ratio) when total energy expenditure, duration, and mean intensity remain unchanged. In spite of the apparent benefit of these strategies, the amount of fat oxidized after exercise may be inconsequential compared with that oxidized during the exercise bout.

Restricted access

Marcus P. Tartaruga, Carlos B. Mota, Leonardo A. Peyré-Tartaruga and Jeanick Brisswalter

Purpose:

To identify the effect of allometric scaling on the relationship between running efficiency (R Eff) and middle-distancerunning performance according to performance level.

Methods:

Thirteen male recreational middle-distance runners (mean ± SD age 33.3 ± 8.4 y, body mass 76.4 ± 8.6 kg, maximal oxygen uptake [VO2max] 52.8 ± 4.6 mL · kg−1 · min−1; G1) and 13 male high-level middle-distance runners (age 25.5 ± 4.2 y, body mass 62.8 ± 2.7 kg, VO2max 70.4 ± 1.9 mL · kg−1 · min−1; G2) performed a continuous incremental test to volitional exhaustion to determine VO2max and a 6-min submaximal running test at 70% of VO2max to assess R Eff.

Results:

Significant correlation between R Eff and performance were found for both groups; however, the strongest correlations were observed in recreational runners, especially when using the allometric exponent (respectively for G1, nonallometric vs allometric scaling: r = .80 vs r = .86; and for G2, nonallometric vs allometric scaling: r = .55 vs r = .50).

Conclusion:

These results indicate that an allometric normalization may improve endurance-performance prediction from R Eff values in recreational, but not in elite, runners.

Restricted access

Jeffrey E. Herrick, Judith A. Flohr, Davis L. Wenos and Michael J. Saunders

Purpose:

This study compared the metabolic and performance effects of riding front-only suspension (FS) and front-and-rear suspension (FRS) mountain bicycles on an off-road course that simulated competitive cross-country race conditions (>105 min in duration, with ∼70% of time spent riding uphill).

Methods:

Seven competitive mountain bikers (73.8 ± 7.6 kg; 61.0 ± 4.3 mL·kg–1·min–1) completed two randomized FS and FRS trials. Bikes were similar, excluding rear wheel suspension on the FRS, which increased bike weight by ∼2 kg. Each trial consisted of four laps of rugged 8 km trail with 154 m of elevation gain per lap. The first three laps were performed at ∼70% of VO2max; VO2, HR, and RPE were collected during the first and third laps. The final lap was performed as a maximal time-trial effort.

Results:

During the first and third laps, VO2, HR, and RPE were similar between FS and FRS. However, FS was significantly faster than FRS during the ascending segment of the course (17.6 ± 2.9 vs 18.9 ± 3.4 min, P = .035), despite similar VO2 (P = .651). Although not statistically significant, FRS tended to be faster than FS during the descending portion of the course (8.1 ± 2.0 vs 9.1 ± 2.1, P = .067) at similar VO2. Performance during the final time-trial lap was significantly faster for FS than FRS (24.9 ± 3.9 min, 27.5 ± 4.9 min, P = .008).

Conclusion:

FS was faster than FRS over a course that simulated competitive cross-country race conditions. The faster times were likely the result of improved cycling economy during ascending, which were at least partially influenced by the lighter weight of the FS.

Restricted access

Louise Croft, Suzanne Dybrus, John Lenton and Victoria Goosey-Tolfrey

Purpose:

To examine the physiological profiles of wheelchair basketball and tennis and specifically to: (a) identify if there are differences in the physiological profiles of wheelchair basketball and tennis players of a similar playing standard, (b) to determine whether the competitive physiological demands of these sports differed (c) and to explore the relationship between the blood lactate [Bla] response to exercise and to identify the sport specific heart rate (HR) training zones.

Methods:

Six elite athletes (4 male, 2 female) from each sport performed a submaximal and VO2 peak test in their sport specific wheelchair. Heart rate, VO2, and [Bla] were measured. Heart rate was monitored during international competitions and VO2 was calculated from this using linear regression equations. Individual HR training zones were identified from the [Bla–] profile and time spent within these zones was calculated for each match.

Results:

Despite no differences in the laboratory assessment of HRpeak, the VO2peak was higher for the basketball players when compared with the tennis players (2.98 ± 0.91 vs 2.06 ± 0.71; P = .08). Average match HR (163 ± 11 vs 146 ± 16 beats-min–1; P = .06) and average VO2 (2.26 ± 0.06 vs 1.36 ± 0.42 L-min-1; P = .02) were higher during actual playing time of basketball when compared with whole tennis play. Consequently, differences in the time spent in the different training zones within and between the two sports existed (P < .05).

Conclusions:

Wheelchair basketball requires predominately high-intensity training, whereas tennis training requires training across the exercise intensity spectrum.

Restricted access

Michail Lubomirov Michailov, Audry Morrison, Mano Mitkov Ketenliev and Boyanka Petkova Pentcheva

Traditional treadmill or bicycle ergometry neglects the upper-body musculature that predominantly limits or terminates rock-climbing performance (ie, the inability to continually pull up one’s body mass or “hang on”).

Purpose:

To develop an incremental maximal upper-body ergometer test (UBT) to evaluate climbers’ aerobic fitness and sport-specific work capacity and to compare these results with a traditional treadmill protocol.

Methods:

Eleven elite sport climbers (best redpoint grade Fr.8b) performed a UBT on a vertically mounted rowing ergometer and, on a separate occasion, performed a maximal incremental treadmill test (TMT). Cardiorespiratory parameters were measured continuously. Lactate (La) samples were collected.

Results:

Peak oxygen consumption (VO2peak) and heart rate in UBT and TMT were 34.1 ± 4.1 vs 58.3 ± 2.6 mL · min−1 · kg−1 and 185 ± 8 vs 197 ± 8 beats/min, respectively, and both variables were of significantly lower magnitude during UBT (P < .001). End-of-test La levels for UBT (11.9 ± 1.7 mmol/L) and TMT (12.3 ± 2.5 mmol/L) were similar (P = .554). Treadmill VO2peak was not correlated with either upper-body (UB) VO2peak (P = .854) or redpoint and on-sight climbing grade ability (P > .05). UB VO2peak and peak power output per kg body mass were both strongly correlated (P < .05) with climbing grade ability. The highest correlation coefficient was calculated between current on-sight grade and UB VO2peak (r = .85, P = .001).

Conclusion:

UBT aerobic- and work-capacity results were strongly correlated to climbing-performance variables and reflected sport-specific fatigue, and TMT results were not. UBT is preferred to TMT to test and monitor dedicated and elite rock climbers’ training status.