Renaud Legrand

Influence of successive bouts of fatiguing exercise on perceptual and physiological markers during an incremental exercise test

The purpose of this study was to examine the effects of a succession of fatiguing stages, on ratings of perceived exertion (RPE) and estimated time limits (ETL) during an incremental exercise test. Twenty-seven cyclists performed a continuous incremental test and a discontinuous test with randomized workloads. A linear mixed model was used to compare the RPE, ETL, respiratory gas, heart rate, and blood data obtained during the two exercise tests. RPE and ETL were not significantly different between the tests. Ventilation, breathing frequency, heart rate, and blood lactate concentration were significantly higher during the last incremental test workloads. In conclusion, although the incremental exercise test generated higher cardiorespiratory and muscular workloads than observed during the randomized exercise test, most likely due to a greater fatiguing process, these higher workloads did not influence the perceptual response.

The effect of a one-leg cycling aerobic training program during the rehabilitation period in soccer players with anterior cruciate ligament reconstruction.

Objectives:To examine cardiorespiratory fitness, resting cardiac parameters, and muscle oxygenation changes in soccer players having undergone anterior cruciate ligament reconstruction and to assess the benefits of a one-leg cycling (OLC) aerobic training program performed during the rehabilitation period. Design:Randomized clinical trial. Setting:Outpatient clinic, primary care. Patients:Twenty-four, male, regional-level soccer players who had undergone surgical reconstruction of the anterior cruciate ligament of the knee. Intervention:Patients were randomly assigned to 1 of 2 groups: either an individualized OLC aerobic training program with the untreated leg plus a rehabilitation program (training group, TG) or a group that received the same rehabilitation program but without aerobic training (control group, CG). Main Outcome Measures:Outcome measurements assessed before (T1) and after 6 weeks (T2) were stroke volume (SV) and end-diastolic volume (EDV) during resting cardiac echography measurement and peak work rate (Wpeak), peak O2 uptake (&OV0312;&OV0312;o2peak), peak minute ventilation (&OV0312;&OV0312;epeak), first and second ventilatory threshold (VT1 and VT2), leg muscle oxygenation (LMO2), and blood volume (LMBV) during maximal graded tests performed with the untreated leg. Results:At T1, there was no significant difference between TG and CG. For TG, Wpeak, &OV0312;&OV0312;epeak, VT1, VT2, LMO2, and LMBV at each work rate were significantly higher at T2 than at T1. For CG, Wpeak, &OV0312;&OV0312;o2peak, &OV0312;&OV0312;epeak, VT2, SV, and EDV decreased significantly at T2 in comparison with T1. Conclusions:One-leg cycling training could involve specific adaptations in comparison to a standard rehabilitation program. Moreover, OLC training during rehabilitation seems to stop the effects of hypoactivity.

One-Leg Cycling Versus Arm Cranking: Which is Most Appropriate for Physical Conditioning After Knee Surgery?

OBJECTIVE To compare the cardiorespiratory responses, blood lactate concentration and perceived exertion between 1-leg cycling and arm cranking. DESIGN Comparison of exercise modalities. SETTING Hospital. PARTICIPANTS Fourteen men who had undergone knee surgery were evaluated during rehabilitation. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Each patient performed 2 maximal graded tests: 1-leg cycling and arm cranking exercise, with a 7-day interval. Respiratory gas exchange, heart rate, blood lactate concentration, and the ratings of perceived exertion (RPE) were measured. RESULTS Peak power output, peak minute ventilation, peak oxygen uptake (Vo(2)peak), and peak heart rate did not differ significantly between 1-leg cycling and arm cranking. The first and second ventilatory thresholds occurred at above 40% and 72% of Vo(2)peak, respectively, in both tests. The maximal lactate concentrations and the RPE values were significantly higher during arm cranking (+10%, +12%, respectively, P<.05) compared with corresponding 1-leg cycling values. CONCLUSIONS The maximal cardiorespiratory values were not different between arm cranking and 1-leg cycling. However, the RPE and blood lactate concentration were lower when the exercise was performed with the lower limb. Thus 1-leg cycling may be more easily tolerated than arm cranking by patients participating in aerobic conditioning after knee surgery.

Entraînement en endurance à partir du membre inférieur sain chez des footballeurs amateurs opérés de ligamentoplastie de genou

OBJECTIVE To examine cardiorespiratory fitness changes in subjects having undergone knee surgery and to assess the benefits of one-leg cycling aerobic training program during the rehabilitation period. METHOD Two groups of 12 patients took part in this study. The control group profited from a five weeks conventional rehabilitation in day hospital without cardiorespiratory training. The second group profited in supplement from a one-leg cycling aerobic training program with the valid leg. The subjects were trained for 21 min, by alternating 3 min at 70% and 3 min at 85% of VO(2 peak). They totaled 15 sessions spread over five weeks. The initial evaluation (T1) is carried out the first day of rehabilitation and the final evaluation (T2) at a distance within 35 days. The evaluation consisted in realizing a maximal graded tests starting from the valid leg. RESULTS After five weeks of conventional rehabilitation, we record a reduction of peak power output (W(peak)), peak oxygen uptake (VO(2 peak)) and peak minute ventilation (VE(peak)), respectively of 11, 12 and 13% for the control group. On the other hand, in T2, the training group has on average identical maximum values and some of them increased (W(peak): +14%; VE(peak): +15%). The first and second ventilatory thresholds appear with higher intensities of exercises. CONCLUSION After knee surgery, conventional rehabilitation does not limit cardiorespiratory deconditioning. One leg cycling appears to be an adapted method to stop the effects of hypoactivity.