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Robert P. Lamberts, Theresa N.C. Mann, Gerard J. Rietjens and Hendrik H. Tijdink

Iliac blood-flow restrictions causing painful and “powerless” legs are often attributed to overtraining and may develop for some time before being correctly diagnosed. In the current study, differences between actual performance parameters and performance parameters predicted from the Lamberts and Lambert Submaximal Cycle Test (LSCT) were studied in a world-class cyclist with bilateral kinking of the external iliac artery before and after surgery. Two performance-testing sessions, including a peak-poweroutput (PPO) test and a 40-km time trial (TT) were conducted before surgery, while 1 testing session was conducted after the surgery. Actual vs LSCT-predicted performance parameters in the world-class cyclists were compared with 82 symptom-free trained to elite male cyclists. No differences were found between actual and LSCT-predicted PPO before and after surgical intervention. However, there were differences between actual and LSCT-predicted 40-km TT time in the tests performed before the surgery (2:51and 2:55 min:s, respectively). These differences were no longer apparent in the postsurgery 40-km TT (2 s). This finding suggests that iliac blood-flow restrictions seem to mainly impair endurance performance rather than peak cycling performance. A standard PPO test without brachial ankle blood-pressure measurements might not be able to reflect iliac bloodflow restrictions. Differences between actual and LSCT-predicted 40-km TT time may assist in earlier referral to a cardiovascular specialist and result in earlier detection of iliac blood-flow restrictions.

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Benoit Capostagno, Michael I. Lambert and Robert P. Lamberts

Purpose:

To determine whether a submaximal cycling test could be used to monitor and prescribe high-intensity interval training (HIT).

Methods:

Two groups of male cyclists completed 4 HIT sessions over a 2-wk period. The structured-training group (SG; n = 8, VO2max = 58.4 ± 4.2 mL · min−1 · kg−1) followed a predetermined training program while the flexible-training group (FG; n = 7, VO2max = 53.9 ± 5.0 mL · min−1 · kg−1) had the timing of their HIT sessions prescribed based on the data of the Lamberts and Lambert Submaximal Cycle Test (LSCT).

Results:

Effect-size calculations showed large differences in the improvements in 40-km time-trial performance after the HIT training between SG (8 ± 45 s) and FG (48 ± 42 s). Heart-rate recovery, monitored during the study, tended to increase in FG and remain unchanged in SG.

Conclusions:

The results of the current study suggest that the LSCT may be a useful tool for coaches to monitor and prescribe HIT.

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Robert P. Lamberts

In high-performance cycling, it is important to maintain a healthy balance between training load and recovery. Recently a new submaximal cycle test, known as the Lamberts and Lambert Submaximal Cycle Test (LSCT), has been shown to be able to accurately predict cycling performance in 15 well-trained cyclists. The aim of this study was to determine the predictive value of the LSCT in 102 trained to elite cyclists (82 men and 20 women). All cyclists performed an LSCT test followed by a peak-power-output (PPO) test, which included respiratory-gas analysis for the determination of maximal oxygen consumption (VO2max). They then performed the LSCT test followed by a 40-km time trial (TT) 72 h later. Average power output during the 3 stages of the LSCT increased from 31%, 60%, and 79% of PPO, while the ratings of perceived exertion increased from 8 to 13 to 16. Very good relationships were found between actual and LSCT-predicted PPO (r = .98, 95%CI: .97–.98, P < .0001), VO2max (r = .96, 95%CI: .97–.99, P < .0001) and 40-km-TT time (r = .98, 95%CI: .94–.97, P < .0001). No gender differences were found when predicting cycling performance from the LSCT (P = .95). The findings of this study show that the LSCT is able to accurately predict cycling performance in trained to elite male and female cyclists and potentially can be used to prescribe and fine-tune training prescription in cycling.

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Laura J.S. Moore, Adrian W. Midgley, Gemma Thomas, Shane Thurlow and Lars R. McNaughton

Purpose:

The aim of this work was to determine whether the consumption of pre-exercise high– or low–glycemic index (GI) meals has a beneficial effect on time trial performance.

Methods:

Eight male cyclists were provided with either a high-GI or low-GI meal, providing 1 g·kg−1 body mass of carbohydrate, 45 min before performing a 40-km time trial on a Velotron cyclePro.

Results:

Time trial performance was significantly improved in the low-GI trial (92.5 ± 5.2 min) compared with the high-GI trial (95.6 ± 6.0 min) (P = .009). Blood glucose concentrations at the point of exhaustion were significantly higher in the low-GI trial (5.2± 0.6 mmol·L−1) compared with the high-GI trial (4.7 ± 0.7 mmol·L−1) (P = .001). There was no significant difference in estimated carbohydrate oxidation data between the low-GI (2.51 ± 1.74 g·min−1) and high-GI (2.18 ± 1.53 g·min−1) meals (P = .195). No significant difference in estimated fat oxidation was observed between the low-GI (0.15 ± 0.15 g·min−1) and high-GI (0.29 ± 0.18 g·min−1) diets (P = .83).

Conclusions:

The improvement in time trial performance for the low-GI trial may be associated with an increased availability of glucose to the working muscles, contributing additional carbohydrate for oxidation and possibly sparing limited muscle and liver glycogen stores.

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Julia H. Goedecke, Richard Elmer, Steven C. Dennis, Ingrid Schloss, Timothy D. Noakes and Estelle V. Lambert

The effects of ingesting different amounts of medium-chain triacylglycerol (MCT) and carbohydrate (CHO) on gastric symptoms, fuel metabolism, and exercise performance were measured in 9 endurance-trained cyclists. Participants, 2 hr after a standardized lunch, cycled for 2 hr at 63% of peak oxygen consumption and then performed a simulated 40-km time trial (T trial). During the rides, participants ingested either 10% 14C-glucose (GLU), 10% 14C-GLU + 1.72%MCT(LO-MCT), or 10% l4C-GLU + 3.44%MCT(HI-MCT) solutions: 400 ml at the start of exercise and then 100 ml every lOmin.MCTingestiondid not affect gastrointestinal symptoms. It only raised serum free fatty acid (FFA) and ß-hydroxybutyrate concentrations. Higher FFA and ß-hydroxybutyrate concentrations with MCT ingestion did not affect fuel oxidation or T-trial performance. The high CHO content of the pretrial lunch increased starting plasma insulin levels, which may have promoted CHO oxidation despite elevated circulating FFA concentrations with MCT ingestion.

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Richard B. Kreider, Gary W. Miller, Deborah Schenck, Charles W. Cortes, Victor Miriel, C. Thomas Somma, Pam Rowland, Caroll Turner and Dawn Hill

Six trained male cyclists and triathletes participated in a double blind study to determine the effects of phosphate loading on maximal and endurance exercise performance. Subjects ingested either 1 gm of tribasic sodium phosphate or a glucose placebo four times daily for 3 days prior to performing either an incremental maximal cycling test or a simulated 40-km time trial on a computerized race simulator. They continued the supplementation protocol for an additional day and then performed the remaining maximal or performance exercise test. Subjects observed a 17-day washout period between testing sessions and repeated the experiment with the alternate supplement regimen in identical fashion. Metabolic data were collected at 15-sec intervals while venous blood samples and 2D-echocardiographic data were collected during each stage of exercise during the maximal exercise test and at 8-km intervals during the 404cm time trial. Results indicate that phosphate loading attenuated anaerobic threshold, increased myocardial ejection fraction and fractional shortening, increased maximal oxidative capacity, and enhanced endurance performance in competitive cyclists and triathletes.

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Jeremiah J. Peiffer and Chris R. Abbiss

The purpose of this study was to examine the effect of environmental temperature on variability in power output, self-selected pacing strategies, and performance during a prolonged cycling time trial. Nine trained male cyclists randomly completed four 40 km cycling time trials in an environmental chamber at 17°C, 22°C, 27°C, and 32°C (40% RH). During the time trials, heart rate, core body temperature, and power output were recorded. The variability in power output was assessed with the use of exposure variation analysis. Mean 40 km power output was significantly lower during 32°C (309 ± 35 W) compared with 17°C (329 ± 31 W), 22°C (324 ± 34 W), and 27°C (322 ± 32 W). In addition, greater variability in power production was observed at 32°C compared with 17°C, as evidenced by a lower (P = .03) standard deviation of the exposure variation matrix (2.9 ± 0.5 vs 3.5 ± 0.4 units, respectively). Core temperature was greater (P < .05) at 32°C compared with 17°C and 22°C from 30 to 40 km, and the rate of rise in core temperature throughout the 40 km time trial was greater (P < .05) at 32°C (0.06 ± 0.04°C·km–1) compared with 17°C (0.05 ± 0.05°C·km–1). This study showed that time-trial performance is reduced under hot environmental conditions, and is associated with a shift in the composition of power output. These finding provide insight into the control of pacing strategies during exercise in the heat.

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.2013-0301 Invited Commentary Evolutionary Pattern of Improved 1-Mile Running Performance Carl Foster * Jos J. de Koning * Christian Thiel * 7 2014 9 4 715 719 10.1123/ijspp.2013-0318 Brief Report Impairment of 40-km Time-Trial Performance but Not Peak Power Output With External Iliac Kinking: A

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Romuald Lepers, Paul J. Stapley and Thomas Cattagni

closely to those of Olympic distance triathlon (ie, 1500-m swimming, 40-km cycling, and 10-km running) were analyzed. Because the 40-km time trial is not an official competitive distance in cycling, we chose to analyze 1-hour track-cycling performance. For sprint events, we compared disciplines having

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Owen Jeffries, Mark Waldron, Stephen D. Patterson and Brook Galna

-second sprints, 9 4-minute time trials, 10 and longer duration 40-km time trials despite a ∼6% reduction in performance time outdoors. 11 Relatively little is known about variation in power output in response to more immediate external demands of pacing during outdoor cycling such as short strategic