Cycling Sprint Test Research Articles

Use of NIRS to assess effect of training on peripheral muscle oxygenation changes in elite rugby players performing repeated supramaximal cycling tests.

In most team sports, intermittent high intensity sprint efforts combined with short recovery periods have been identified as a key factor of physical performance; the ability to repeat these efforts at a sustained level is of great importance. Near-infrared spectroscopy (NIRS) has been proposed as a tool to monitor muscle oxygenation changes during such sprint efforts. The purpose of this study was to observe muscle reoxygenation rate (reoxy rate) (% s⁻¹) between sprint efforts in a repeat sprint cycle test. A two wavelength spatially resolved NIR spectrometer (Portamon, Artinis Inc.) was used to assess reoxy rate changes in the vastus lateralis of the dominant leg before and after a training stimulus. Eight UK premiership academy level rugby players were assessed (age 20.6 ± 0.9) years; height 187 ± 0.6 cm; weight 109.5 ± 8.6 kg; quadriceps skin fold 16.6 ± 4.5 mm); the subjects completed ten repeated 10-s cycle sprints interspersed with 40 s recovery, upon a Wattbike Pro cycle. Hemoglobin variables (ΔHHb, ΔtHb, ΔO₂Hb, ΔTSI %) during the sprint and the post-sprint reoxygenation rate (%TSI s⁻¹) were measured. During both cycle tests all subjects experienced a drop in muscle oxygen saturation (Pre-Δ - 12.39 ± 6.01 %), Post-Δ - 14.83 ± 3.88 %). Post-training, there was an increase in the extent of desaturation (drop in TSI %) in the group means, both for the biggest single change and the average of all ten changes. Seven out of eight players showed an increase based on the maximum change and six based on the average of their ten tests. Additionally, seven out of eight players showed a significant increase in ΔHHb (Pre-Δ + 76.80 ± 61.92, Post-Δ + 121.28 ± 69.76) (p < 0.01) (including the one player who did not show a significant effect on the TSI measure). Players who exercised at the highest power tended to decrease their muscle oxygenation to a greater extent. The number of bike training sessions undertaken correlated with improvements in post-exercise recovery of oxygenation (R = 0.63). The simplest explanation for the increase in desaturation following training is an increase in muscle oxygen consumption due to an increase in mitochondrial content. This results in an increased extraction of delivered oxygen as confirmed by the HHb data. In conclusion, NIRS is able to measure positive training effects on muscle oxygen extraction, at the level of the individual elite athlete.

Plasma volume variation with exercise: a crucial consideration for obese adolescent boys

Previous studies have demonstrated that considerable plasma volume variations (ΔPV) occur during and after exposure to different environmental and physiological conditions. Such changes have an important effect on plasma concentration of metabolite values. Currently, no study has examined ΔPV in individuals with different body weight status and used ΔPV to correct plasma solute values. The aims of this study were to assess (i) the effect of body weight status on ΔPV and (ii) the impact of these variations on lactate ([La]) and glucose ([Glu]) concentrations in normal-weight, overweight, and obese adolescent boys. Participants performed a cycling sprint test at their maximal power output. ΔPV were calculated using 2 methods, and both lactate and glucose concentrations were compared using total circulating values (T) and corrected values (cr) for ΔPV: [La]T vs. [La]cr and [Glu]T vs. [Glu]cr. Following exercise, ΔPV values decreased significantly from rest value and were higher in obese compared with overweight and normal-weight boys (p < 0.01). Moreover, ΔPV were correlated with body weight status (r = 0.85; p < 0.05). While [La]T and [Glu]T differed among the groups, no difference persisted when these values were corrected for ΔPV. The differences between total circulating and corrected values were significant. The impact of body weight status on ΔPV and thus on various plasma measures in response to exercise is important and should be considered in further studies.

The Reliability of a 30-s Sprint Test on the Wattbike Cycle Ergometer

To determine the reliability of a 30-s sprint cycle test on the Wattbike cycle ergometer. Over 3 consecutive weeks, 11 highly trained cyclists (mean ± SD; age 31 ± 6 y, mass 74.6 ± 10.6 kg, height 180.5 ± 8.1cm) completed four 30-s maximal sprints on a Wattbike ergometer after a standardized warm-up. The sprint test implemented a "rolling start" that consisted of a 60-s preload (at an intensity of 4.5 W/kg) before the 30-s maximal sprint. Variables determined across the duration of the sprint were peak power (Wpeak), mean power (Wmean), W/kg, mean cadence (rpm), maximum heart rate (n = 10), and postexercise blood lactate. The average intraclass correlation coefficients between trials (2v1, 3v2, 4v3, 4v1) were Wpeak .97 (90%CI .94-.99), Wmean .99 (90%CI .97-1.00), W/kg .96 (90%CI .91-.98), mean cadence .96 (90%CI .92-.99), maximum heart rate .99 (90%CI .97-.99), and postexercise blood lactate .94 (90%CI .87-.98). The average typical error of measurement (expressed as a CV% and absolute value between trials-2v1, 3v2, 4v3, 4v1) was Wpeak 4.9%, 52.7 W; Wmean 2.4%, 19.2 W; W/kg 2.3%, 0.18 W/kg; mean cadence 1.4%, 1.6 rpm; maximum heart rate 0.9%, 1.6 beats/min; and postexercise blood lactate 4.6%, 0.48 mmol/L. A 30-s sprint test on the Wattbike cycle ergometer is highly reproducible in trained cyclists.

The Influence of Recovery Duration After Heavy Resistance Exercise on Sprint Cycling Performance

The aim of this study was to determine the optimal recovery duration after prior heavy resistance exercise (PHRE) when performing sprint cycling. On 5 occasions, separated by a minimum of 48 hours, 10 healthy male subjects (mean ± SD), age 25.5 ± 7.7 years, body mass 82.1 ± 9.0 kg, stature 182.6 ± 87 cm, deadlift 1-repetition maximum (1RM) 142 ± 19 kg performed a 30-second sprint cycling test. Each trial had either a 5-, 10-, 20-, or 30-minute recovery after a heavy resistance activity (5 deadlift repetitions at 85% 1RM) or a control trial with no PHRE in random order. Sprint cycling performance was assessed by peak power (PP), fatigue index, and mean power output over the first 5 seconds (MPO5), 10 seconds (MPO10), and 30 seconds (MPO30). One-way analysis of variance with repeated measures followed by paired t-tests with a Bonferroni adjustment was used to analyze data. Peak power, MPO5, and MPO10 were all significantly different during the 10-minute recovery trial to that of the control condition with values of 109, 112, and 109% of control, respectively; no difference was found for the MPO30 between trials. This study supports the use of PHRE as a strategy to improve short duration, up to, or around 10-second, sprint activity but not longer duration sprints, and a 10-minute recovery appears to be optimal to maximize performance.

The Effects of Passive Warm-Up Vs. Whole-Body Vibration on High-Intensity Performance During Sprint Cycle Exercise

The purpose of this study was to compare the effects of passive warm-up (PW), whole-body vibration (WBV), and control (C) on high-intensity performance during sprint cycle exercise. Six recreationally trained men performed a 30-second sprint cycle test after the 3 aforementioned conditions; each test was carried out on a different day after balanced-order experimental tests. The WBV consisted of 5 minutes of squats associated with WBV (45 Hz, 2 mm). The PW consisted of 30 minutes of PW using a thermal blanket on the thighs and legs (35 W). The C consisted of 30 minutes of no warm-up with the subject lying down. Motor neuron excitability from the vastus lateralis muscle, evaluated by electromyography (EMG), was determined before exercise at rest and during sprint cycle exercise. Blood lactate levels (BLs), evaluated by spectroscopy, and muscle temperature (MT) of the thigh, estimated indirectly by measuring skin temperature, were determined at following time points: before exercise at rest (before and after experimental conditions), immediately, and 3 minutes after the 30-second sprint cycle test. Peak power, relative power, relative work, time of peak power, and pedaling cadence were significantly higher in the WBV compared with that for C (p < 0.05). Although MT was significantly greater in PW compared with that in WBV and C before exercise (p < 0.01), no significant differences were observed between the experimental conditions for BL immediately after sprint cycle exercise (p = 0.35) and in EMG during sprint cycle exercise (p = 0.16). Thus, it is plausible to suggest WBV as a method for an acute increase in high-intensity performance during sprint cycle exercise for athletes immediately before competition or training.

Warm-up effects on muscle oxygenation, metabolism and sprint cycling performance

To investigate the effects of warm-up intensity on all-out sprint cycling performance, muscle oxygenation and metabolism, 8 trained male cyclists/triathletes undertook a 30-s sprint cycling test preceded by moderate, heavy or severe warm up and 10-min recovery. Muscle oxygenation was measured by near-infrared spectroscopy, with deoxyhaemoglobin ([HHb]) during the sprint analysed with monoexponential models with time delay. Aerobic, anaerobic-glycolytic and phosphocreatine energy provision to the sprint were estimated from oxygen uptake and lactate production. Immediately prior to the sprint, blood [lactate] was different for each warm up and higher than resting for the heavy and severe warm ups (mod. 0.94±0.36, heavy 1.92±0.64, severe 4.37±0.93mmoll(-1) P<0.05), although muscle oxygenation was equally raised above rest. Mean power during the sprint was lower following severe compared to moderate warm up (mod. 672±54, heavy 666±56, severe 655±59W, P<0.05). The [HHb] kinetics during the sprint were not different among conditions, although the time delay before [HHb] increased was shorter for severe versus moderate warm up (mod. 5.8±0.6, heavy 5.6±0.9, severe 5.2±0.7s, P<0.05). The severe warm up was without effect on estimated aerobic metabolism, but increased estimated phosphocreatine hydrolysis, the latter unable to compensate for the reduction in estimated anaerobic-glycolytic metabolism. It appears that despite all warm ups equally increasing muscle oxygenation, and indicators of marginally faster oxygen utilisation at the start of exercise following a severe-intensity warm up, other energy sources may not be able to fully compensate for a reduced glycolytic rate in sprint exercise with potential detrimental effects on performance.

Caffeine’s effect on intermittent sprint cycling performance with different rest intervals

The purpose of this study was to investigate the effects of caffeine ingestion on the performance of an intermittent sprint cycling test (ISCT) with different rest intervals. Fourteen males with team sport experience consumed 6 mg kg(-1) of caffeine or a placebo 60 min prior to completing two sets of an ISCT with 4-min rest intervals. Each set consisted of 12 × 4-s sprints with 20- or 90-s active recovery intervals at 60-70 rpm. Blood lactate was collected at baseline and immediately following the completion of six sprints in each set. At 20-s recovery intervals, peak power and total work were not significantly different between conditions during the ISCT (P > 0.05); but caffeine reduced 6.31% effort for mean power in Sprint 10 of the later stage, as well as an increased fatigue index and elevated blood lactate levels during the ISCT (P < 0.05). At 90-s recovery intervals, peak power, mean power, and total work under caffeine conditions were significantly higher than under placebo conditions during the ISCT (P < 0.05), but no differences were apparent in fatigue index and blood lactate levels (P > 0.05). In conclusion, caffeine ingestion may be ergolytic, affecting performance and fatigue development in the later stage during a prolonged and intermittent sprint test with a short recovery interval. However, caffeine produces an ergogenic effect in the initial stage of an intermittent sprint performance with a longer recovery interval.

No Difference In Sprint Cycling Performance Tests On A Stationary And Mobile Ergometer

PURPOSE: To determine if there is a difference in sprint cycling performance performed on a stationary ergometer indoors compared to sprint cycling performance a regular road racing bicycle outdoors. METHODS: Eight national level cyclists, (Age 21.3 ± 3.3 years, Weight 74.4 ± 10 kg, Height 178 ± 4.7 cm) volunteered to participate in the study. Subjects performed two different maximal sprint cycling tests in a randomized crossover design on a traditional weight basket ergometer equipped with a SRM Professional powermeter, and on a regular road racing bicycle equipped with the same SRM powermeter. The two tests were a high speed sprint starting a ∼100 RPM and a low speed sprint from a standing start. Each subject performed 3 sprints on each ergometer and condition, and the highest 0.5 s value was reported. All values are reported as mean ± standard deviation. Students T-test was used to test for a difference between ergometers. RESULTS: Maximal power output in the high speed sprint was 1325 ± 317 W for the stationary ergometer and 1300 ± 305 W for the mobile ergometer. Maximal power output in the low speed sprint was 1414 ± 378 W for the stationary ergometer and 1281 ± 170 W, with no significant difference between the two different ergometers. CONCLUSIONS: There was no significant difference between maximal sprint cycling tests performed indoors on a stationary weight basket ergometer and on a regular road racing bicycle performed outdoors.

Catecholamine Response to Exercise in Obese, Overweight, and Lean Adolescent Boys

The aim of this study was to examine the effect of body fat percentage on the plasma catecholamine response to a cycling sprint test (CST) in sedentary adolescent boys. In this study, 31 adolescent boys (9 obese (% body fat = 31.0% ± 3.0%), 11 overweight (% body fat = 24.0% ± 1.6%), and 11 lean (% body fat = 16.0% ± 1.9%)), matched for peak oxygen consumption, completed a CST consisting of six 6-s maximal sprints with 2 min of passive rest between each repetition. Performance of each subject was determined as the mean power output (PO(mean)) developed during the CST. Plasma lactate, epinephrine, and norepinephrine concentrations were determined successively at rest, after a 10-min warm-up, immediately after the CST, and after 20 min of passive recovery. Although groups were not different in age, height, or peak oxygen consumption (mL·kg(-1) fat-free mass·min(-1)), maximal epinephrine concentration was significantly (P < 0.05) higher in lean vs obese and was negatively correlated to body fat percentage (r = -0.60, P < 0.05). Maximal norepinephrine values were higher in lean versus overweight and obese, and a negative relationship was found between maximal norepinephrine concentration and body fat percentage (r = -0.60, P < 0.05). Maximal lactate concentration was higher in lean versus overweight and obese (14.7 ± 3.3, 10.4 ± 2.7, and 10.2 ± 2.5 mM in lean, overweight, and obese, respectively). A significant relationship was also obtained between maximal norepinephrine and maximal epinephrine values with both maximal lactate concentration (r = 0.60 and r = 0.60, P < 0.05, respectively) and PO(mean) (r = 0.65 and r = 0.6, P < 0.05). Our results show that the catecholamine response to a CST was affected by body fat percentage, with reduced epinephrine and norepinephrine values in overweight and obese adolescents.

Optimum loading for maximizing muscle power output: the effect of training history

Although the effect of external load on the mechanical output of individual muscle has been well documented, the literature still provides conflicting evidence regarding whether the optimum loading (L(opt)) for exerting the maximum muscle power output (MPO) could be different for individuals with different levels of strength and power. The aim of this study was to explore the effect of training history on L(opt) that maximizes MPO during the 6-s maximal cycling sprint test. Forty healthy young males (strength-and speed-trained athletes, and physically active and sedentary non-athletes) were tested on maximum strength, and on peak MPO when loaded 5-12% of body weight (BW). As expected, the strength trained and sedentary participants, respectively, revealed the highest and lowest strengths and MPO (p < 0.001). However, the main finding was a significant across-group difference in L(opt) (p < 0.001) revealing the values 9.7% (for strength trained), 9.2% (speed trained), 8.7% (active), and 8.0% of BW (sedentary individuals). This suggests that the effects of external loading on maximum MPO in complex functional movements could be training history dependent. In addition to revealing a sensitivity of the 6-s maximal cycling sprint tests (and, perhaps, other maximum cycling tests), the results suggest that the external loading in routine MPO tests should not be solely adjusted to a fixed percentage of subject's BW (as routinely done in standard tests), but also to their training history. The same phenomenon remains to be evaluated in a number of other routine tests of MPO and other maximum performance tasks.

Fatigue in repeated-sprint exercise is related to muscle power factors and reduced neuromuscular activity

The purpose of this study was (1) to determine the relationship between each individual's anaerobic power reserve (APR) [i.e., the difference between the maximum anaerobic (Pana) and aerobic power (Paer)] and fatigability during repeated-sprint exercise and (2) to examine the acute effects of repeated sprints on neuromuscular activity, as evidenced by changes in the surface electromyogram (EMG) signals. Eight healthy males carried out tests to determine Pana (defined as the highest power output attained during a 6-s cycling sprint), Paer (defined as the highest power output achieved during a progressive, discontinuous cycling test to failure) and a repeated cycling sprint test (10 x 6-s max sprints with 30 s rest). Peak power output (PPO) and mean power output (MPO) were calculated for each maximal 6-s cycling bout. Root mean square (RMS) was utilized to quantify EMG activity from the vastus lateralis (VL) muscle of the right leg. Over the ten sprints, PPO and MPO decreased by 24.6 and 28.3% from the maximal value (i.e., sprint 1), respectively. Fatigue index during repeated sprints was significantly correlated with APR (R = 0.87; P < 0.05). RMS values decreased over the ten sprints by 14.6% (+/-6.3%). There was a strong linear relationship (R2 = 0.97; P < 0.05) between the changes in MPO and EMG RMS from the vastus lateralis muscle during the ten sprints. The individual advantage in fatigue-resistance when performing a repeated sprint task was related with a lower anaerobic power reserve. Additionally, a suboptimal net motor unit activity might also impair the ability to repeatedly generate maximum power outputs.

Effect of oral contraceptive cycle phase on performance in team sport players

The purpose of this study was to examine whether common team sport performance variables (anaerobic power, reactive strength and repeat sprint ability) are affected by acute hormonal fluctuation within a monophasic oral contraceptive (OC) cycle. Ten female team sport athletes completed performance tests at three time points of a single OC cycle, during the consumption phase (CONS), early (WITH1) and late in the withdrawal phase (WITH2). Tests included drop jumps (30cm and 45cm heights), a counter movement jump, a 10s cycle sprint test and a 5x 6s repeated sprint cycle test. Resting endogenous serum oestradiol and progesterone concentrations were also measured. No significant differences were observed between phases for the counter movement jump and cycle tests (total work and peak power). Reactive strength measured from the 30cm drop height was significantly lower during WITH2 (162+/-38cms(-1)) compared to both CONS (177+/-44cms(-1)) and WITH1 (178+/-40cms(-1)) (p<0.05). Reactive strength measured from the 45cm drop height was significantly higher in CONS (178+/-48cms(-1)) compared to both WITH1 and WITH2 (161+/-39cms(-1) and 158+/-29cms(-1), respectively) (p<0.05). Serum oestradiol levels were greater during WITH2 compared to both WITH1 and CONS (p<0.05) but there was no difference in serum progesterone levels. The results demonstrate that for female team sport athletes, only reactive strength varied significantly throughout an OC cycle, possibly due to the action of hormones on neuromuscular timing and the stretch-shortening cycle.

PHYSIOLOGICAL AND PERFORMANCE TEST CORRELATES OF PROLONGED,HIGH-INTENSITY, INTERMITTENT RUNNING PERFORMANCE IN MODERATELY TRAINED WOMEN TEAM SPORT ATHLETES

A large number of team sports require athletes to repeatedly produce maximal or near maximal sprint efforts of short duration interspersed with longer recovery periods of submaximal intensity. This type of team sport activity can be characterized as prolonged, high-intensity, intermittent running (PHIIR). The primary purpose of the present study was to determine the physiological factors that best relate to a generic PHIIR simulation that reflects team sport running activity. The second purpose of this study was to determine the relationship between common performance tests and the generic PHIIR simulation. Following a familiarization session, 16 moderately trained (VO2max = 40.0 +/- 4.3 ml x kg(-1) x min(-1)) women team sport athletes performed various physiological, anthropometrical, and performance tests and a 30-minute PHIIR sport simulation on a nonmotorized treadmill. The mean heart rate and blood lactate concentration during the PHIIR sport simulation were 164 +/- 6 b x min(-1) and 8.2 +/- 3.3 mmol x L(-1), respectively. Linear regression demonstrated significant relationships between the PHIIR sport simulation distance and running velocity attained at a blood lactate concentration of 4 mmol x L(-1) (LT) (r = 0.77, p < 0.05), 5 x 6-second repeated cycle sprint work (r = 0.56, p < 0.05), 30-second Wingate test (r = 0.61, p < 0.05), peak aerobic running velocity (Vmax) (r = 0.69, p < 0.05), and Yo-Yo Intermittent Recovery Test (Yo-Yo IR1) distance (r = 0.50, p < 0.05), respectively. These results indicate that an increased LT is associated with improved PHIIR performance and that PHIIR performance may be monitored by determining Yo-Yo IR1 performance, 5 x 6-second repeated sprint cycle test work, 30-second Wingate test performance, Vmax, or LT. We suggest that training programs should focus on improving both LT and Vmax for increasing PHIIR performance in moderately trained women. Future studies should examine optimal training methods for improving these capacities in team sport athletes.

The Influence of Endurance Training on Multiple Sprint Cycling Performance

The aims of the present study were to examine the effects of endurance training on multiple sprint cycling performance and to evaluate the influence of recovery duration on the magnitude of those effects. Twenty-one physically active male university students were randomly assigned to either an experimental (n = 12) or a control (n = 9) group. The experimental group cycled for 20 minutes each day, 3 times per week, for 6 weeks at 70% of the power output required to elicit maximal oxygen uptake (VO2max). Multiple sprint performance was assessed using 2 maximal (20 x 5 seconds) sprint cycling tests with contrasting recovery periods (10 or 30 seconds). All tests were conducted on a friction-braked cycle ergometer. Relative to controls, training resulted in a 0.2 L.min(-1) increase in mean VO2max (95% likely range: -0.04 to 0.44 L.min(-1)). Changes in anaerobic capacity (determined by maximal accumulated oxygen deficit) over the same period were trivial (p = 0.96). After training, the experimental group showed significant improvements ( approximately 40 W), relative to controls, in multiple sprint measures of peak and mean power output. In contrast, training-induced reductions in fatigue were trivial (p = 0.63), and there were no significant between-protocol differences in the magnitude of any effects. In summary, 6 weeks of endurance training resulted in substantial improvements in multiple sprint cycling performance, the magnitude of the improvements being largely unaffected by the duration of the intervening recovery periods.

Reproducibility of a 6-s maximal cycling sprint test

The purpose of this study was to examine the reproducibility in measures of power output during a 6-s, maximal cycling sprint test. Eleven healthy, moderately-trained males (mean+/-S.D.; age=19+/-1 year; height=181.5+/-6.2 cm; mass=76.9+/-9.5 kg; peak oxygen uptake 54.9+/-6.1 mL kg(-1)min(-1)) performed a 6-s standing sprint on a front-access cycle ergometer on four separate occasions. Peak power output (PPO) was significantly higher (4.9%; P<0.05) in trial 2 compared with trial 1, whereas there were no significant differences between trials 2, 3 and 4. Similarly, the mean power output (MPO) for trial 2 was higher (5.8%; P<0.05) than in trial 1, but there were no difference across trials 2, 3 and 4. The within-subject coefficient of variation (CV) from trials 2 to 4 was 2.8 and 2.9% for PPO and MPO, respectively, while the CV calculated using data from the third and fourth trial was lower: 1.8 and 2.5% for PPO and MPO, respectively. The results of the study showed that reliable power outputs can be obtained after one familiarization session in subjects unfamiliar with maximal cycling sprint exercise. However, the inclusion of an extra familiarization session ensured more stable power outputs. Therefore, two trials should allow adequate familiarization with the maximal 6-s cycling test.

Validity of cycling peak power as measured by a short-sprint test versus the Wingate anaerobic test

To validate the measurement of peak power output (PPO) using a short cycling sprint test (inertial load (IL) test), we compare it to the widely accepted Wingate anaerobic test (WAnT). Fifteen healthy, young, active subjects performed 2 experimental trials. In each trial, subjects warmed up and sprinted 4 times for the IL test. After recovery, they cycled for 30 s at maximum capacity for the WAnT. The experimental trial was replicated 3 d later to test for reliability. Inter- and intra-day PPO measured with the IL test was very reliable (R(1) = 0.99 and R(1) = 0.94, respectively). The correlation between the IL and WAnT was highly significant (r = 0.82; P < 0.001), although the absolute PPO values were markedly higher for the IL test (1268 +/- 41 W vs. 786 +/- 27 W; P < 0.001). In conclusion, cycling PPO can be validly assessed with the IL test. The higher PPO attained with an IL test could be related to better identification of peak power, since both velocity and resistance are free to vary during the sprint in comparison with the WAnT, where resistance is fixed. Owing to the short duration of the sprint (4 s) and high intra-day reliability despite a short recovery time (180 s), the IL test is optimal for repeated measurements of anaerobic performance.

The Influence of Endurance Training on Multiple Sprint Cycling Performance

PURPOSE: The aims of the present study were to examine the effects of endurance training on multiple sprint cycling performance and to evaluate the influence of recovery duration on the magnitude of those effects. METHODS: Twenty-one physically active male university students were randomly assigned to either an experimental (n = 12) or a control (n = 9) group. The experimental group cycled for 20 minutes each day, three times per week, for six weeks at 70% of the power output required to elicit maximal oxygen uptake (VO2max). Multiple sprint performance was assessed using two maximal (20 × 5 s) sprint cycling tests with contrasting recovery periods (10 s or 30 s). All tests were conducted on a friction-braked cycle ergometer. The effects of endurance training on the various indices of multiple sprint performance were determined using one-way analysis of covariance. RESULTS: Relative to controls, training resulted in a 0.2 L.min−1 increase in mean VO2max (95% likely range: −0.04 to 0.44 L.min−1). Changes in anaerobic capacity (determined by maximal accumulated oxygen deficit) over the same period were trivial. After training, the experimental group showed substantial improvements, relative to controls, in multiple sprint measures of maximum and mean power output (range: 29 to 52 W). In contrast, reductions in fatigue were trivial (range: −0.6 to −1.5%). CONCLUSIONS: Six weeks of endurance training resulted in substantial improvements in multiple sprint cycling performance, the magnitude of the improvements being largely unaffected by the duration of the intervening recovery periods.

Aerobic and Anaerobic Correlates of Multiple Sprint Cycling Performance

The aims of this study were to examine (a) the relationship between maximal oxygen uptake (VO(2)max) and several performance indices of multiple sprint cycling; (b) the relationship between maximal accumulated oxygen deficit (MAOD) and those same performance indices; and (c) the influence of recovery duration on the magnitude of those relationships. Twenty-five physically active men completed a VO(2)max test, a MAOD test, and 2 maximal intermittent (20 x 5 seconds) sprint cycling tests with contrasting recovery periods (10 seconds or 30 seconds). Mean +/- SD for age, height, and body mass were 20.6 +/- 1.5 years, 177.2 +/- 5.4 cm, and 78.2 +/- 8.2 kg, respectively. All tests were conducted on a friction-braked cycle ergometer with subsequent data normalized for body mass. Moderate (0.3 < or = r < 0.5) positive correlations were observed between power output data and MAOD (range, 0.31-0.46; 95% confidence limits, -0.10 to 0.72). Moderate to large positive correlations also were observed between power output data and VO(2)max, the magnitude of which increased as values were averaged across all sprints (range, 0.45-0.67; 95% confidence limits 0.07-0.84). Correlations between fatigue and VO(2)max were greater in the intermittent protocol with 30-second recovery periods (r = -0.34; 95% confidence limits, 0.06 to -0.65). The results of this study reflect the complex energetics associated with multiple sprint work. Though the findings add support to the idea that multiple sprint sports demand a combination of speed and endurance, further longitudinal research is required to confirm the relative importance of these parameters.

THE INFLUENCE OF RECOVERY DURATION ON MULTIPLE SPRINT CYCLING PERFORMANCE

The purpose of this study was to examine the influence of recovery duration on various measures of multiple sprint cycling performance. Twenty-five physically active men completed 2 maximal multiple sprint (20 X 5 seconds) cycling tests with contrasting recovery periods (10 or 30 seconds). The mean ± SD values for age, height, and body mass were 20.6 ± 1.5 years, 177.2 ± 5.4 cm, and 78.2 ± 8.2 kg, respectively. All tests were conducted on a friction-braked cycle ergometer. Longer (30 seconds) recovery periods resulted in significantly (p < 0.05) higher measures of maximum (;4%) and mean (;26%) power output, the former appearing to result from a potentiation effect during the first few sprints. Thirty-second recovery periods also corresponded with significantly lower measures of fatigue (absolute difference: 16.1%; 95% likely range: 14.1–18.2%), heart rate, respiratory exchange ratio, and oxygen uptake. Blood lactate and ratings of perceived exertion (6–20 scale) increased progressively throughout both protocols and were significantly lower with 30-second recovery periods. The results of this study illustrate the considerable influence of recovery duration on various measures of multiple sprint work. Although the precise mechanisms of this response require further investigation, coaches and sport scientists should consider these findings when attempting to develop or evaluate the performance capabilities of athletes involved in multiple sprint sports.

Single-Fiber MHC Polymorphic Expression Is Unaffected by Sprint Cycle Training

The present investigation examined single-fiber MHC alterations in response to high-intensity, short-duration, sprint cycle training. Ten untrained college-age male subjects participated in 8 wk of a progressive sprint cycle training program. Training involved 15-s maximal sprints separated by 5 min of rest beginning with four sprints x 2 d in week 1 and increasing to six sprints x 3 d at week 8. Muscle samples from the vastus lateralis were obtained before and after training. A 30-s sprint cycle test was used to evaluate performance before and after training. For the 30-s sprint, mean power and total work increased from pre to post. Single-fiber analyses revealed a reduction in the MHC IIx isoform (2.0 +/- 1.0 to 0.2 +/- 0.1%, pre to post, P < 0.05) and an increase in MHC IIa (P = 0.08), whereas there was no change in hybrid fiber composition (total hybrids = 24%). Generally, MHC IIa content increased and MHC IIx decreased (P < 0.05) as demonstrated by homogenate analyses of tissue samples. We report that as little as 32 min of high-intensity sprint cycle training over 8 wk is sufficient to improve sprinting performance. This training response is accompanied by an increase in MHC IIa and reduction in MHC IIx content of the vastus lateralis. However, short-duration, high-intensity, sprint cycle training does not cause a reduction in hybrid muscle fiber content.