The effects of ionized and nonionized compression garments on sprint and endurance cycling

ABSTRACT: Burden, RJ and Glaister, M. The effects of ionized and nonionized compression garments on sprint and endurance cycling. J Strength Cond Res 26(10): 2837-2843, 2012-The aim of this study was to examine the effects of ionized and nonionized compression tights on sprint and endurance cycling performance. Using a randomized, blind, crossover design, 10 well-trained male athletes (age: 34.6 ± 6.8 years, height: 1.80 ± 0.05 m, body mass: 82.2 ± 10.4 kg, V[Combining Dot Above]O2max: 50.86 ± 6.81 ml·kg·min) performed 3 sprint trials (30-second sprint at 150% of the power output required to elicit V[Combining Dot Above]O2max [pV[Combining Dot Above]O2max] + 3 minutes recovery at 40% pV[Combining Dot Above]O2max + 30-second Wingate test + 3 minutes recovery at 40% pV[Combining Dot Above]O2max) and 3 endurance trials (30 minutes at 60% pV[Combining Dot Above]O2max + 5 minutes stationary recovery + 10-km time trial) wearing nonionized compression tights, ionized compression tights, or standard running tights (control). There was no significant effect of garment type on key Wingate measures of peak power (grand mean: 1,164 ± 219 W, p = 0.812), mean power (grand mean: 716 ± 68 W, p = 0.800), or fatigue (grand mean: 66.5 ± 6.9%, p = 0.106). There was an effect of garment type on blood lactate in the sprint and the endurance trials (p < 0.05), although post hoc tests only detected a significant difference between the control and the nonionized conditions in the endurance trial (mean difference: 0.55 mmol·L, 95% likely range: 0.1-1.1 mmol·L). Relative to control, oxygen uptake (p = 0.703), heart rate (p = 0.774), and time trial performance (grand mean: 14.77 ± 0.74 minutes, p = 0.790) were unaffected by either type of compression garment during endurance cycling. Despite widespread use in sport, neither ionized nor nonionized compression tights had any significant effect on sprint or endurance cycling performance.     

The influence of recovery duration after heavy resistance exercise on sprint cycling performance

ABSTRACT: Thatcher, R, Gifford, R, and Howatson, G. The influence of recovery duration after heavy resistance exercise on sprint cycling performance. J Strength Cond Res 26(11): 3089-3094, 2012-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.     

Prior eccentric exercise reduces v[combining dot above]o2peak and ventilatory threshold but does not alter movement economy during cycling exercise

Exercise-induced muscle damage (EIMD) has been shown to reduce force production and result in delayed-onset soreness and pain in the damaged muscle(s). Cycling in the presence of EIMD reduces peak power output and time-trial performance. However, its effect on peak aerobic capacity has not been widely studied. The purpose of this study was to examine the impact of EIMD targeted specifically to the quadriceps muscle group on peak oxygen consumption (V[Combining Dot Above]O2peak) during cycling. Ten participants (4 men, 6 women) completed a V[Combining Dot Above]O2peak test on a cycle ergometer before and 48 hours after performing 24 eccentric contractions with their right and left quadriceps with a weight equal to 120% of 1-repetition maximal concentric strength (1RM). The EIMD was assessed using 1RM, and muscle soreness was assessed using a 100-mm visual analog scale. The presence of EIMD was confirmed by a 9% reduction in 1RM (p = 0.0001) and increased ratings of soreness from 2.4 ± 2.1 to 24.6 ± 10.8 mm (p = 0.001). The V[Combining Dot Above]O2peak was reduced from 46.2 ± 9.7 to 41.8 ± 10.7 ml·kg·min (10%; p = 0.01) with participants terminating exercise at lower heart rates 191 ± 9 vs. 186 ± 10 b·min (p = 0.02) and power output 248 ± 79 vs. 238 ± 81 W (p = 0.02) after EIMD. Additionally, ventilatory threshold decreased from 34.2 ± 7.8 to 30.5 ± 8.5 ml·kg·min (11%; p = 0.031). Despite the reduction in V[Combining Dot Above]O2peak, cycling economy (p = 0.17) did not differ pre-EIMD and post-EIMD. These findings indicate that EIMD reduced peak aerobic exercise capacity to an extent that could result in meaningful reductions in exercise performance. The reduction is likely attributable to a combination of reduced strength, earlier accumulation of lactic acid, and heightened muscle pain during exercise.     

Effects of isocaloric carbohydrate vs. carbohydrate-protein supplements on cycling time to exhaustion

The purpose of this study was to investigate the effects of isocaloric carbohydrate (CHO) and carbohydrate-protein (CHO-Pro) supplements on time to exhaustion. Eleven moderately aerobically fit adults (V[Combining Dot Above]O2max= 48.3 ± 6.5 ml·kg·min) performed a maximal cycle ergometer test for the determination of V[Combining Dot Above]O2max. At least 72 hours later, the participants performed a time-to-exhaustion test at a power output equivalent to the power output when subjects were at 75% of their V[Combining Dot Above]O2max. Either the CHO or the CHO-Pro supplement was administered at 0, 30, 60, 90, and 120 minutes after this test. After 3 hours of recovery and supplement ingestion, a second time-to-exhaustion test was performed. This testing protocol was repeated for the third visit, but the supplement not given during the second visit was administered. The results indicated that there was no significant difference in time to exhaustion after isocaloric CHO (pretest 22.4 ± 2.84 minutes, posttest 25.4 ± 4.45 minutes) and CHO-Pro (pretest 22.3 ± 3.46 minutes, posttest 24.0 ± 5.08 minutes) supplementation. Carbohydrate and CHO-Pro ingestion after exercise appear to have similar effects on short-term recovery.     

Metabolic response of different high-intensity aerobic interval exercise protocols

ABSTRACT: Gosselin, LE, Kozlowski, KF, DeVinney-Boymel, L, and Hambridge, C. Metabolic response of different high-intensity aerobic interval exercise protocols. J Strength Cond Res 26(10): 2866-2871, 2012-Although high-intensity sprint interval training (SIT) employing the Wingate protocol results in significant physiological adaptations, it is conducted at supramaximal intensity and is potentially unsafe for sedentary middle-aged adults. We therefore evaluated the metabolic and cardiovascular response in healthy young individuals performing 4 high-intensity (～90% V[Combining Dot Above]O2max) aerobic interval training (HIT) protocols with similar total work output but different work-to-rest ratio. Eight young physically active subjects participated in 5 different bouts of exercise over a 3-week period. Protocol 1 consisted of 20-minute continuous exercise at approximately 70% of V[Combining Dot Above]O2max, whereas protocols 2-5 were interval based with a work-active rest duration (in seconds) of 30/30, 60/30, 90/30, and 60/60, respectively. Each interval protocol resulted in approximately 10 minutes of exercise at a workload corresponding to approximately 90% V[Combining Dot Above]O2max, but differed in the total rest duration. The 90/30 HIT protocol resulted in the highest V[Combining Dot Above]O2, HR, rating of perceived exertion, and blood lactate, whereas the 30/30 protocol resulted in the lowest of these parameters. The total caloric energy expenditure was lowest in the 90/30 and 60/30 protocols (～150 kcal), whereas the other 3 protocols did not differ (～195 kcal) from one another. The immediate postexercise blood pressure response was similar across all the protocols. These finding indicate that HIT performed at approximately 90% of V[Combining Dot Above]O2max is no more physiologically taxing than is steady-state exercise conducted at 70% V[Combining Dot Above]O2max, but the response during HIT is influenced by the work-to-rest ratio. This interval protocol may be used as an alternative approach to steady-state exercise training but with less time commitment.     

Caffeine and sprinting performance: dose responses and efficacy

The aims of this study were to evaluate the effects of caffeine supplementation on sprint cycling performance and to determine if there was a dose-response effect. Using a randomized, double-blind, placebo-controlled design, 17 well-trained men (age: 24 ± 6 years, height: 1.82 ± 0.06 m, and body mass(bm): 82.2 ± 6.9 kg) completed 7 maximal 10-second sprint trials on an electromagnetically braked cycle ergometer. Apart from trial 1 (familiarization), all the trials involved subjects ingesting a gelatine capsule containing either caffeine or placebo (maltodextrin) 1 hour before each sprint. To examine dose-response effects, caffeine doses of 2, 4, 6, 8, and 10 mg·kg bm(-1) were used. There were no significant (p ≥ 0.05) differences in baseline measures of plasma caffeine concentration before each trial (grand mean: 0.14 ± 0.28 μg·ml(-1)). There was, however, a significant supplement × time interaction (p < 0.001), with larger caffeine doses producing higher postsupplementation plasma caffeine levels. In comparison with placebo, caffeine had no significant effect on peak power (p = 0.11), mean power (p = 0.55), or time to peak power (p = 0.17). There was also no significant effect of supplementation on pretrial blood lactate (p = 0.58), but there was a significant time effect (p = 0.001), with blood lactate reducing over the 50 minute postsupplementation rest period from 1.29 ± 0.36 to 1.06 ± 0.33 mmol·L(-1). The results of this study show that caffeine supplementation has no effect on short-duration sprint cycling performance, irrespective of the dosage used.     

Achievement of v[combining dot above]o2max criteria during a continuous graded exercise test and a verification stage performed by college athletes

ABSTRACT: Mier, CM, Alexander, RP, and Mageean, AL. Achievement of V[Combining Dot Above]O2max criteria during a continuous graded exercise test and a verification stage performed by college athletes. J Strength Cond Res 26(10): 2648-2654, 2012-The purpose of this study was to determine the incidence of meeting specific V[Combining Dot Above]O2max criteria and to test the effectiveness of a V[Combining Dot Above]O2max verification stage in college athletes. Thirty-five subjects completed a continuous graded exercise test (GXT) to volitional exhaustion. The frequency of achieving various respiratory exchange ratio (RER) and age-predicted maximum heart rate (HRmax) criteria and a V[Combining Dot Above]O2 plateau within 2 and 2.2 ml·kg·min (<2SD of the expected increase in V[Combining Dot Above]O2) were measured and tested against expected frequencies. After 10 minutes of active recovery, 10 subjects who did not demonstrate a plateau completed a verification stage performed at supramaximal intensity. From the GXT, the number of subjects meeting V[Combining Dot Above]O2max plateau was 5 (≤2 ml·kg·min) and 7 (≤2.2 ml·kg·min), RER criteria 34 (≥1.05), 32 (≥1.10), and 24 (≥1.15), HRmax criteria, 35 (<85%), 29 (<10 b·min) and 9 (HRmax). The V[Combining Dot Above]O2max and HRmax did not differ between GXT and the verification stage (53.6 ± 5.6 vs. 55.5 ± 5.6 ml·kg·min and 187 ± 7 vs. 187 ± 6 b·min); however, the RER was lower during the verification stage (1.15 ± 0.06 vs. 1.07 ± 0.07, p = 0.004). Six subjects achieved a similar V[Combining Dot Above]O2 (within 2.2 ml·kg·min), whereas 4 achieved a higher V[Combining Dot Above]O2 compared with the GXT. These data demonstrate that a continuous GXT limits the college athlete's ability to achieve V[Combining Dot Above]O2max plateau and certain RER and HR criteria. The use of a verification stage increases the frequency of V[Combining Dot Above]O2max achievement and may be an effective method to improve the accuracy of V[Combining Dot Above]O2max measurements in college athletes.     

Comparison of two aerobic field tests in young tennis players

ABSTRACT: Fargeas-Gluck, M-A and Léger, LA. Comparison of two aerobic field tests in young tennis players. J Strength Cond Res 26(11): 3036-3042, 2012-This study compares the maximal responses of a new aerobic tennis field test, the NAVTEN to a known aerobic field test, often used with young tennis players, that is, the continuous multistage 20-m shuttle run test (20-m SRT). The NAVTEN is an intermittent (1-minute/1-minute) multistage test with side-to-side displacements and ball hitting. Ten young elite tennis players aged 12.9 ± 0.3 (mean ± SD) randomly performed both tests and were continuously monitored for heart rate (HR) and oxygen uptake (V[Combining Dot Above]O2) using the Vmax ST (Sensormedics). The 20-m SRT and NAVTEN show similar HRpeak (202 ± 6.1 vs. 208 ± 9.5, respectively) and V[Combining Dot Above]O2peak (54.2 ± 5.9 vs. 54.9 ± 6.0 ml·kg·min). Pearson correlations between both tests were 0.88 and 0.92 for V[Combining Dot Above]O2peak and maximal speed, respectively. The NAVTEN yielded V[Combining Dot Above]O2peak values that are typical for active subjects of that age and are similar to the 20-m SRT supporting its use to measure aerobic fitness of young tennis players in specific and entertaining field conditions. The fact that two-thirds of the tennis players achieved a different ranking (±1 rank) with the NAVTEN and the 20-m SRT suggests that the NAVTEN may be more specific than the 20-m SRT to assess aerobic fitness of tennis players. From a practical point of view, the NAVTEN test is more specific and pedagogical for young tennis players even though both tests yield similar maximal values.     

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 (approximately 4%) and mean (approximately 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.     

Are changes in maximal squat strength during preseason training reflected in changes in sprint performance in rugby league players?

Because previous research has shown a relationship between maximal squat strength and sprint performance, this study aimed to determine if changes in maximal squat strength were reflected in sprint performance. Nineteen professional rugby league players (height = 1.84 ± 0.06 m, body mass [BM] = 96.2 ± 11.11 kg, 1 repetition maximum [1RM] = 170.6 ± 21.4 kg, 1RM/BM = 1.78 ± 0.27) conducted 1RM squat and sprint tests (5, 10, and 20 m) before and immediately after 8 weeks of preseason strength (4-week Mesocycle) and power (4-week Mesocycle) training. Both absolute and relative squat strength values showed significant increases after the training period (pre: 170.6 ± 21.4 kg, post: 200.8 ± 19.0 kg, p < 0.001; 1RM/BM pre: 1.78 ± 0.27 kg·kg(-1), post: 2.05 ± 0.21 kg·kg(-1), p < 0.001; respectively), which was reflected in the significantly faster sprint performances over 5 m (pre: 1.05 ± 0.06 seconds, post: 0.97 ± 0.05 seconds, p < 0.001), 10 m (pre: 1.78 ± 0.07 seconds, post: 1.65 ± 0.08 seconds, p < 0.001), and 20 m (pre: 3.03 ± 0.09 seconds, post: 2.85 ± 0.11 seconds, p < 0.001) posttraining. Whether the improvements in sprint performance came as a direct consequence of increased strength or whether both are a function of the strength and power mesocycles incorporated into the players' preseason training is unclear. It is likely that the increased force production, noted via the increased squat performance, contributed to the improved sprint performances. To increase short sprint performance, athletes should, therefore, consider increasing maximal strength via the back squat.     

Effects of short-term quercetin supplementation on soldier performance

The purpose was to assess the short-term effects of quercetin supplementation on aerobically demanding soldier performance. In a double-blind crossover study, 16 male soldiers performed 3 days of aerobically demanding exercise under 3 conditions: Baseline (B), Placebo (P), and Quercetin (Q). Day 1 was a treadmill V[Combining Dot Above]O?peak test. Days 2 and 3 were identical, consisting of 75 minutes of loaded treadmill marching (LM) and a subsequent cycling time trial (TT) to complete 200 kJ of work. After B condition, the soldiers consumed 2 energy bars, each containing 0 mg (placebo) or 500 mg of quercetin (1,000 mg·d?1) for 8.5 days. Beginning day 6 of supplementation, the soldiers performed the 3 exercise days. There was a significant (p < 0.05) increase in plasma Q after Q supplementation. Repeated measures analyses of variance revealed no differences after P or Q supplementation as compared with B in V[Combining Dot Above]O?peak (B = 48.9 ± 1.1, P = 49.3 ± 1.1, Q = 48.8 ± 1.2 ml·kg?1·min?1) or TT time (B = 18.4 ± 1.0, P = 18.5 ± 1.1, Q = 18.3 ± 1.0 minutes [mean day 1 and day 2]). The respiratory exchange ratio during LM did not differ across treatments (B = 0.87 ± 0.03, P = 0.87 ± 0.03, Q = 0.86 ± 0.04 [mean day 1 and day 2]). Ratings of perceived exertion were not affected by Q supplementation during the V[Combining Dot Above]O?peak test, LM or TT. Supplementation of 1,000 mg·d?1 of quercetin for 8.5 days had no positive effect on aerobically demanding soldier performance. It is possible that a different dosing regimen, a combination of antioxidants or a different form of quercetin supplementation, may be needed to produce an increase in soldier performance.     

Physiological responses and time-motion characteristics of 4-a-side small-sided game in young soccer players: the influence of different team formation methods

ABSTRACT: K?klü, Y, Ers?z, G, Alemdaro?lu, U, A???, A, and ?zkan, A. Physiological responses and time-motion characteristics of 4-A-side small-sided game in young soccer players: The influence of different team formation methods. J Strength Cond Res 26(11): 3118-3123, 2012-The purpose of this study was to examine the influence of different team formation methods on the physiological responses to and time-motion characteristics of 4-a-side small-sided games (SSG4) in young soccer players. Thirty-two young soccer players (age 16.2 ± 0.7 years; height 172.9 ± 6.1 cm; body mass 64.1 ± 7.7 kg) voluntarily participated in this study. Anthropometric measurements, technical tests, and maximum oxygen uptake (V[Combining Dot Above]O2max) tests were carried out on the players. The SSG4 teams were then created using 4 different methods: according to the coaches' subjective evaluation (CE), technical scores (TS), V[Combining Dot Above]O2max (AP), and V[Combining Dot Above]O2max multiplied by TSs (CG). The teams thus created played 4 bouts of SSG4 at 2-day intervals. During the SSG4, heart rate (HR) responses, distance covered, and time spent in HRmax zones were recorded. In addition, rating of perceived exertion (RPE) and blood lactate level (La) were determined at the end of the last bout of each SSG4. Percent of HRmax (%HRmax), La, and RPE responses during SSG4 were significantly higher for teams chosen according to AP and CG compared with that according to CE and TS (p < 0.05). In addition, teams chosen by AP and CG spent significantly more time in zone 4 (>90% HRmax ) and covered a greater distance in the high-intensity running zone (>18 km·h) than did teams formed according to TS. Moreover, AP teams covered significantly greater total distance than TS teams did (p < 0.05). In conclusion, to spend more time in both the high-intensity HR zone and the high-intensity running zone, the teams in SSG4 should be formed according to the players' V[Combining Dot Above]O2max values or the values calculated using both the V[Combining Dot Above]O2max and technique scores.     

No differences in O2-cost between V1 and V2 skating techniques during treadmill roller skiing at moderate to steep inclines

Elite crosscountry skiers use both the V1 and V2 techniques on moderate and steep inclines despite previous studies suggesting that the V1 technique is superior in terms of lower O2-cost and better performance on these inclines. However, this has not been studied in elite athletes, and therefore, the aim of this study was to compare O2-cost in these 2 main ski skating techniques in a group of 14 elite male crosscountry skiers (age: 24 ± 3 years, height: 184 ± 6 cm, weight: 79 ± 7 kg, V1 V[Combining Dot Above]O2max: 71.8 ± 3.5 ml·kg·min). With both techniques, the athletes performed submaximal trials for the determination of O2-cost on a roller ski treadmill at 4, 5, and 6° (3 m·s) and maximal trials at 8° (≥3 m·s) for the determination of V[Combining Dot Above]O2max. Video-based kinematic analyses on cycle length and cycle rate (CR) were performed to unravel if there was any relation between these variables and O2-cost. No significant differences in O2-cost or V[Combining Dot Above]O2max between techniques were found. However, large and significant individual variations in physiological response were observed. V2 had a longer cycle length and lower CR than V1 did. No significant correlation was found between CR and O2-cost. This study shows that both V1 and V2 are appropriate techniques for optimizing O2-cost on moderate to steep inclines in elite skiers. However, individual variation suggests that ski skating performance on moderate to steep inclines may be determined by technique preferences of the athletes.     

Rocker-bottom, profile-type shoes do not increase lower extremity muscle activity or energy cost of walking

The purpose of this study was to determine if wearing rocker-bottom shoes with compliant midsoles (RB) influences muscle activity and metabolic cost of walking. Furthermore, we sought to determine if weight differences between shod conditions accounted for any potential change. Twenty-eight subjects (17 women, 11 men, age 22.8 ± 6.6 years; weight 72 ± 20 kg; height 170 ± 6.7 cm; percent body fat 23.0 ± 11.7) walked on a treadmill (0% grade) for 10 minutes at a self-selected speed plus 10% (1.3 ± 0.2 m·s) in each of the following laboratory-provided shoes: flat-bottomed shoe (W), flat-bottomed shoe weight-matched to RB (WM), and RB. Muscle activity of the right side biceps femoris (BF), rectus femoris (RF), gastrocnemius (GA), and tibalis anterior (TA) was recorded for 30 seconds at the beginning, middle, and ending of the 10-minute walk using an electromyography (EMG) system. The average (AVG) and root mean square (RMS) were calculated from full-wave rectified EMG data at each interval. The rate of oxygen consumption (V[Combining Dot Above]O2) was measured for 10 minutes during each condition. A 3 (shoe) × 3 (time) repeated-measures analysis of variance (ANOVA) was used to compare each EMG-dependent variable (AVG and RMS EMG of each muscle), and repeated measures ANOVA was used to test V[Combining Dot Above]O2. Muscle activity (for any muscle) was not influenced by the interaction of shoe and time (p > 0.05). The AVG and RMS for RF, BF, and GA, including V[Combining Dot Above]O2, were not different among shod conditions (W: 9.7 ± 0.6 ml·kg·min; WM: 10.0 ± 0.5 ml·kg·min; RB: 10.1 ± 0.5 ml·kg·min), whereas TA AVG and RMS were lower during RB (p < 0.05). It seems that there is no increase in muscle activity or metabolic cost while wearing RB beyond the flat-bottomed shoe despite there being the rocker-profile design and mass differences.     

Relationship between anaerobic cycling tests and mountain bike cross-country performance

Despite its apparent relevance, there is no evidence supporting the importance of anaerobic metabolism in Olympic crosscountry mountain biking (XCO). The purpose of this study was to examine the correlation between XCO race time and performance indicators of anaerobic power. Ten XCO riders (age: 28 ± 5 years; weight: 68.7 ± 7.7 kg; height: 177.9 ± 7.4 cm; estimated body fat: 5.7 ± 2.8%; estimated ·VO?max: 68.4 ± 5.7 ml·kg?1·min?1) participating in the Lagos Mountain Bike Championship (Brazil) completed 2 separate testing sessions before the race. In the first session, after anthropometric assessments were performed, the cyclists completed a single 30-second Wingate (WIN) test and an intermittent tests consisting of 5 × 30-second WIN tests (50% of the single WIN load) with 30 seconds of recovery between trials. In the second session, the riders performed a maximal incremental test. A significant correlation was found between race time and maximal power on the 5× WIN test (r = -0.79, IC(95%) -0.94 to -0.32, p = 0.006) and the mean average power on the 5× WIN test normalized by body mass (r = -0.63, IC(95%) -0.90 to -0.01, p = 0.048). The finding of the study supports the use of anaerobic tests for assessing mountain bikers participating in XCO competitions and suggests that anaerobic power is an important determinant of performance.     

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 reliability and validity of fatigue measures during short-duration maximal-intensity intermittent cycling

The purpose of the present study was to assess the reliability and validity of fatigue measures, as derived from 4 separate formulae, during tests of repeat sprint ability. On separate days over a 3-week period, 2 groups of 7 recreationally active men completed 6 trials of 1 of 2 maximal (20 x 5 seconds) intermittent cycling tests with contrasting recovery periods (10 or 30 seconds). All trials were conducted on a friction-braked cycle ergometer, and fatigue scores were derived from measures of mean power output for each sprint. Apart from formula 1, which calculated fatigue from the percentage difference in mean power output between the first and last sprint, all remaining formulae produced fatigue scores that showed a reasonably good level of test-retest reliability in both intermittent test protocols (intraclass correlation range: 0.78-0.86; 95% likely range of true values: 0.54-0.97). Although between-protocol differences in the magnitude of the fatigue scores suggested good construct validity, within-protocol differences highlighted limitations with each formula. Overall, the results support the use of the percentage decrement score as the most valid and reliable measure of fatigue during brief maximal intermittent work.     

The effects of a constant sprint-to-rest ratio and recovery mode on repeated sprint performance

It is unclear if a constant sprint-to-rest ratio allows full performance recovery between repeated sprints over different distances. This is important for the development of sprint-training programs. Additionally, there is conflicting evidence on whether active recovery enhances sprint performance. Three repeated sprint protocols were used (22 × 15, 13 × 30, and 8 × 50 m), with each having an active and passive recovery. Each trial was conducted with an initial sprint-to-rest ratio of 1:10. Repeated sprints were analyzed by comparing the first sprint to the last sprint. For the 15-m trials, there were no significant main effects for recovery or time and no significant interaction. For the 30-m trials, there was no main effect for recovery, but a main effect for time (F[1,10] = 15.995, p = 0.003; mean difference = 0.20 seconds, 95% confidence interval [CI] = 0.09-0.31 seconds, d = 1.4 [large effect]). There was no interaction of recovery and time in the 30-m trials. For the 50-m trials, there was no main effect for recovery, but a main effect for time (F[1,10] = 34.225, p = 0.0002; mean difference = 0.39 seconds, 95% CI = 0.24-0.55 seconds, d = 1.3 [large effect]). There was no interaction of recovery and time in the 50-m trials. The results demonstrate that a 1:10 sprint-to-rest ratio allows full performance recovery between 15-m sprints, but not between sprints of 30 or 50 m, and that recovery mode did not influence repeated sprint performance.     

Creatine serum is not as effective as creatine powder for improving cycle sprint performance in competitive male team-sport athletes

This study examined the effects of supplementation with either creatine monohydrate powder in solution (CP) or a widely available creatine serum (CS) on performance in a repeated maximal sprint cycling test (10 x 6 seconds, 24-second passive rest between sprints). Using a randomized, double-blind, crossover design, 11 competitive male athletes supplemented with creatine in 2 forms according to the manufacturer's recommendations on 2 separate occasions. The 2 supplementation protocols were (a) 20 g.day(-1) x 6 days of creatine powder in solution plus a placebo serum (CP) or (b) 5 ml.day(-1) x 6 days of creatine serum plus a placebo powder (CS). Subjects completed 2 familiarization trials before the 6-day supplementation period. A repeated maximal sprint cycling test was performed prior to and immediately postsupplementation. A 7-week washout period separated the 2 supplementation protocols. Subjects' total work (9.6%) and peak power (3.4%) in the cycle sprint improved significantly (p < 0.05) after loading with CP, but there was little change after loading with CS. The present data support previous research findings showing an ergogenic effect of CP supplementation but indicate that supplementation with CS does not affect sprint cycling performance. Although the levels of creatine in each formulation were not determined, a substantial conversion of creatine into creatinine has been reported in many formulations and may explain the present findings.