Intensity Matters: Effect of Different Work-Matched Efforts on Subsequent Performance in Cyclists.

PURPOSE: To assess the effect of 2 work-matched efforts of different intensities on subsequent performance in well-trained cyclists. METHODS: The present study followed a randomized controlled crossover design. Twelve competitive junior cyclists volunteered to participate (age, 17 [1] y; maximum oxygen uptake, 71.0 [4.7] mL·kg-1·min-1). The power-duration relationship was assessed through 2-minute, 5-minute, and 12-minute field tests under fresh conditions (control). On subsequent days and following a randomized order, participants repeated the aforementioned tests after 2 training sessions matched for mechanical work (∼15 kJ/kg) of different intensities (ie, a moderate-intensity continuous-training [60%-70% of critical power; CP] session or a session including high-intensity intervals [3-min repetition bouts at 110%-120% of the CP interspersed by 3-min rest periods]). RESULTS: A significantly lower power output was found in the 2-minute test after the high-intensity training session compared not only with the control condition (-8%, P < .001) but also with the moderate-intensity continuous-training session (-7%, P = .003), with no significant differences between the latter conditions. No significant differences between conditions were found for the remaining tests. As a consequence, the high-intensity training session resulted in significantly lower W' values compared to both the control condition (-27%, P = .001) and the moderate-intensity continuous-training session (-26%, P = .012), with no differences between the 2 latter conditions and with no differences for CP. CONCLUSION: A session including high-intensity intermittent efforts induces a greater fatigue, particularly in short-duration efforts and W', than a work-matched continuous-training session of moderate intensity.

Aortic Diameters and Calcifications in Former World-Class Cyclists.

PURPOSE: Concerns on whether athletes--particularly older ones--are at an increased risk of pathological aortic dilation exist, and the prevalence of aortic calcifications in these individuals is unknown. We aimed to compare the dimensions, distensibility, and prevalence of calcifications in the thoracic aorta between former male professional cyclists (cases) and sex/age-matched controls. METHODS: We used a retrospective cohort design, where cases were former finishers of at least one Grand Tour (Tour de France, Giro d' Italia or Vuelta a España) and controls were untrained individuals with no previous sports history and free of cardiovascular risk. All participants underwent magnetic resonance and computer tomography assessments for the measurement of aortic dimensions and calcifications, respectively. RESULTS: Cases showed larger ( P < 0.05) dimensions than controls for aortic annulus, sinus, and arch, as well as for ascending and descending aorta. However, none of the participants presented with pathological aortic dilation (all diameters <40 mm). A slightly higher prevalence of calcifications in the ascending aorta was observed in cases (13% vs 0% in controls, P = 0.020). Subanalyses confirmed that cases who were still competing (masters category, n = 8) had larger aortic diameters ( P < 0.05) and a greater presence of calcifications in the ascending/descending aorta (38% vs 0% for both segments, P = 0.032) than those who had become inactive ( n = 15). No between-group differences were found for aortic distensibility. CONCLUSIONS: Former professional cyclists, particularly those who are still competing after retirement, show enlarged aortic diameters (albeit without exceeding upper limits of normality). Former professional cyclists also showed a slightly higher prevalence of calcifications in the ascending aorta than controls, although aortic distensibility was not compromised. The clinical relevance of these findings should be the subject of future studies.

Pre-sleep protein supplementation in professional cyclists during a training camp: a three-arm randomized controlled trial.

Background: The effects of pre-sleep protein supplementation on endurance athletes remain unclear, particularly whether its potential benefits are due to the timing of protein intake or solely to an increased total protein intake. We assessed the effects of pre-sleep protein supplementation in professional cyclists during a training camp accounting for the influence of protein timing. Methods: Twenty-four professional U23 cyclists (19 ± 1 years, peak oxygen uptake: 79.8 ± 4.9 ml/kg/min) participated in a six-day training camp. Participants were randomized to consume a protein supplement (40 g of casein) before sleep (n = 8) or in the afternoon (n = 8), or an isoenergetic placebo (40 g of carbohydrates) before sleep (n = 8). Indicators of fatigue/recovery (Hooper index, Recovery-Stress Questionnaire for Athletes, countermovement jump), body composition, and performance (1-, 5-, and 20-minute time trials, as well as the estimated critical power) were assessed as study outcomes. Results: The training camp resulted in a significant (p < 0.001) increase in training loads (e.g. training stress score of 659 ± 122 per week during the preceding month versus 1207 ± 122 during the training camp), which induced an increase in fatigue indicators (e.g. time effect for Hooper index p < 0.001) and a decrease in performance (e.g. time effect for critical power p = 0.002). Protein intake was very high in all the participants (>2.5 g/kg on average), with significantly higher levels found in the two protein supplement groups compared to the placebo group (p < 0.001). No significant between-group differences were found for any of the analyzed outcomes (all p > 0.05). Conclusions: Protein supplementation, whether administered before sleep or earlier in the day, exerts no beneficial effects during a short-term strenuous training period in professional cyclists, who naturally consume a high-protein diet.

Durability in Professional Cyclists: A Field Study.

PURPOSE: To assess durability in professional cyclists, as well as potential associated indicators. METHODS: Twelve male professional cyclists participated in the study (age: 26 [5] y, VO2max: 83.0 [3.6] mL·kg-1·min-1). They performed a 20-minute time trial (TT) on 2 different sessions separated by a 48-hour period: (1) with no previous fatigue (TTFresh) and (2) immediately after a long submaximal ride (approximately 4 h, 40 kJ/kg) (TTFatigue). We then assessed the decay (in percentage) in mean power output (PO) from TTFresh to TTFatigue and its association with different laboratory-based endurance indicators (ventilatory threshold, peak PO, and VO2max) determined through a previous maximal incremental cycling test, as well as with training loads during the 4 weeks preceding the TTs. RESULTS: While no differences were noted in the average heart rate (177 [7] vs 176 [6] beats·min-1, P = .118), there was a significant decay in PO between TTFresh and TTFatigue (386 [29] W vs 375 [28] W [-2.9%], respectively; P = .007), albeit with signs of interindividual variability (range = -8.5% to 1.1%; coefficient of variation = 105%). No significant associations were found between the PO decay and any of the analyzed indicators (all P > .05). CONCLUSIONS: Performance is significantly impaired after a certain amount of work completed (approximately 40 kJ·kg-1) in professional cyclists, and the magnitude of this impairment seems to be not related to "traditional" laboratory-based endurance indicators or to markers of training load. These findings might support the need for specifically assessing durability in cyclists and confirming potential determinants of this parameter.

On- Versus Off-Bike Power Training in Professional Cyclists: A Randomized Controlled Trial.

PURPOSE: To compare the effectiveness of resistance power training (RPT, training with the individualized load and repetitions that maximize power output) and cycling power training (CPT, short sprint training) in professional cyclists. METHODS: The participants (20 [2] y, peak oxygen uptake 78.0 [4.4] mL·kg-1·min-1) were randomly assigned to perform CPT (n = 8) or RPT (n = 10) in addition to their usual training regime for 7 weeks (2 sessions/wk). The training loads were continuously registered using the session rating of perceived exertion. The outcomes included endurance performance (8-min time trial and incremental test), as well as measures of muscle strength/power (1-repetition maximum and mean maximum propulsive power on the squat, hip thrust, and lunge exercises) and body composition (assessed by dual-energy X-ray absorptiometry). RESULTS: No between-group differences were found for training loads or for any outcome (P > .05). Both interventions resulted in increased time-trial performance, as well as in improvements in other endurance-related outcomes (ie, ventilatory threshold, respiratory compensation point; P < .05). A significant or quasi-significant increase (P = .068 and .047 for CPT and RPT, respectively) in bone mineral content was observed after both interventions. A significant reduction in fat mass (P = .017), along with a trend (P = .059) toward a reduced body mass, was observed after RPT, but not CPT (P = .076 for the group × time interaction effect). Significant benefits (P < .05) were also observed for most strength-related outcomes after RPT, but not CPT. CONCLUSION: CPT and RPT are both effective strategies for the improvement of endurance performance and bone health in professional cyclists, although the latter tends to result in greater improvements in body composition and muscle strength/power.

Traditional Versus Optimum Power Load Training in Professional Cyclists: A Randomized Controlled Trial.

PURPOSE: To compare the effectiveness of optimum power load training (OPT, training with an individualized load and repetitions that maximize power output) and traditional resistance training (TRT, same number of repetitions and relative load for all individuals) in professional cyclists. METHODS: Participants (19 [1] y, peak oxygen uptake 75.5 [6] mL/kg/min) were randomly assigned to 8 weeks (2 sessions per week) of TRT (n = 11) or OPT (n = 9), during which they maintained their usual cycle training schedule. Training loads were continuously registered, and measures of muscle strength/power (1-repetition maximum and maximum mean propulsive power on the squat, hip thrust, and lunge exercises), body composition (assessed by dual-energy X-ray absorptiometry), and endurance performance (assessed on both an incremental test and an 8-min time trial) were collected before and at the end of the intervention. RESULTS: OPT resulted in a lower average intensity (percentage of 1-repetition maximum) during resistance training sessions for all exercises (P < .01), but no differences were found for overall training loads during resistance or cycling sessions (P > .05). Both programs led to significant improvements in all strength/power-related parameters, muscle mass (with no changes in total body mass but a decreased fat mass), and time-trial performance (all Ps < .05). A trend toward increased power output at the respiratory compensation point was also found (P = .056 and .066 for TRT and OPT, respectively). No between-groups differences were noted for any outcome (P > .05). CONCLUSION: The addition of either TRT or OPT to an endurance training regimen of elite cyclists results in similar improvements of body composition, muscle strength/power, and endurance performance.

Warming Up Before a 20-Minute Endurance Effort: Is It Really Worth It?

PURPOSE: To analyze the effects of different warm-up protocols on endurance-cycling performance from an integrative perspective (by assessing perceptual, neuromuscular, physiological, and metabolic variables). METHODS: Following a randomized crossover design, 15 male cyclists (35 [9] y; peak oxygen uptake [VO2peak] 66.4 [6.8] mL·kg-1·min-1) performed a 20-minute cycling time trial (TT) preceded by no warm-up, a standard warm-up (10 min at 60% of VO2peak), or a warm-up that was intended to induce potentiation postactivation (PAP warm-up; 5 min at 60% of VO2peak followed by three 10-s all-out sprints). Study outcomes were jumping ability and heart-rate variability (both assessed at baseline and before the TT), TT performance (mean power output), and perceptual (rating of perceived exertion) and physiological (oxygen uptake, muscle oxygenation, heart-rate variability, blood lactate, and thigh skin temperature) responses during and after the TT. RESULTS: Both standard and PAP warm-up (9.7% [4.7%] and 12.9% [6.5%], respectively, P < .001), but not no warm-up (-0.9% [4.8%], P = .074), increased jumping ability and decreased heart-rate variability (-7.9% [14.2%], P = .027; -20.3% [24.7%], P = .006; and -1.7% [10.5%], P = .366). Participants started the TT (minutes 0-3) at a higher power output and oxygen uptake after PAP warm-up compared with the other 2 protocols (P < .05), but no between-conditions differences were found overall for the remainder of outcomes (P > .05). CONCLUSIONS: Compared with no warm-up, warming up enhanced jumping performance and sympathetic modulation before the TT, and the inclusion of brief sprints resulted in a higher initial power output during the TT. However, no warm-up benefits were found for overall TT performance or for perceptual or physiological responses during the TT.