Influence of Recovery Mode on the Maximum Number of Intervals Until Exhaustion During an Aerobic Interval Training Session.

ABSTRACT: Varela-Sanz, A, Sánchez-Otero, T, Tuimil, JL, Boullosa, D, and Iglesias-Soler, E. Influence of recovery mode on the maximum number of intervals until exhaustion during an aerobic interval training session. J Strength Cond Res 37(9): e510-e520, 2023-We analyzed work capacity, cardiometabolic, perceptual, and neuromuscular responses to an aerobic interval training (AIT) running session until exhaustion, with active (AR) vs. passive recovery (PR). Eight well-trained male endurance runners (36.88 ± 7.14 years, 58.22 ± 3.39 ml·kg -1 ·minute -1 ) randomly completed, after familiarizations and the University of Montreal Track Test (UMTT), 2 AIT track running sessions until exhaustion consisting in 2-minute bouts at 100% of maximum aerobic speed (MAS), with 2 minutes of recovery at 80% of the velocity associated to the second ventilatory threshold (vVT 2 ) (i.e., AR), or no exercise (i.e., PR). Oxygen consumption (V̇O 2 ), heart rate (HR), blood lactate [La], rating of perceived exertion (RPE), and countermovement jump (CMJ) were continuously monitored during sessions. The level of statistical significance was set at p ≤ 0.05. PR resulted in longer time to exhaustion during sessions (13.9 vs. 11.6 bouts, p = 0.045), but lower HR ( p < 0.01) when compared with AR. Time spent over 90% of maximum oxygen consumption (V̇O 2max ), blood lactate concentrations, neuromuscular performance, and RPE did not differ between AR and PR ( p > 0.05). Thus, PR allowed runners to perform more work intervals and, therefore, to accumulate a greater volume. On the other hand, when training goals are focused on reaching a higher chronotropic stress (i.e., higher HR) during the training session, athletes would obtain more benefits from AR. This study also demonstrates that the current volume recommendations for AIT are far below (54-64.5%) the maximum training capacity of well-trained runners.

Active vs. passive recovery during an aerobic interval training session in well-trained runners.

PURPOSE: To compare cardio-metabolic, perceptual and neuromuscular responses to an aerobic interval training (AIT) running session, with active (AR) vs. passive recovery (PR). METHODS: Eleven well-trained male distance runners (36.63 ± 6.93 years, 59.26 ± 5.27 mL·kg-1·min-1, ⁓ 35 min in 10 km) completed the University of Montréal Track Test (UMTT) and 2 AIT sessions on track in random order, which consisted of 4 × 2 min at 100% of the maximum aerobic speed (MAS), with 2 min of AR at 80% of the velocity associated to the second ventilatory threshold (vVT2), or no exercise (i.e., PR). During sessions, oxygen consumption (V̇O2), heart rate (HR), blood lactate [La], rating of perceived exertion (RPE), and countermovement jump (CMJ) were continuously monitored. RESULTS: There were no differences in time spent in the "red zone" (i.e. > 90% V̇O2max) between sessions (222 ± 73 s AR vs. 230 ± 104 s PR, p = 0.588), although the PR exhibited a greater time spent at peak V̇O2 close to significance (117 ± 114 vs. 158 ± 109 s, p = 0.056). However, the AR elicited a higher mean V̇O2 (49.62 ± 5.91 vs. 47.46 ± 4.20 mL·kg-1·min-1, p = 0.021). The AR favored a lower [La] after sessions (6.93 ± 2.22 vs. 6.24 ± 1.93 mmol·L-1, p = 0.016) and a higher RPE during sessions (15 ± 0.45 vs. 14 ± 0.47, p = 0.045). Meanwhile, the CMJ was significantly potentiated during both sessions. CONCLUSION: Considering that PR elicited lower perceptual loading for a similar cardiorespiratory response, its use would be preferable, at least, for this type of AIT running sessions.

Effect of set configuration on hemodynamics and cardiac autonomic modulation after high-intensity squat exercise.

The aim of this study was to compare the effect of two different high-intensity resistance exercise (RE) set configurations on the following: systolic blood pressure (SBP), rate pressure product (RPP), heart rate (HR) variability (HRV), and HR complexity (HRC). Ten well-trained males performed three parallel squat sets until failure (traditional training; TT) with the four repetitions maximum load (4RM), and a rest of 3 min between sets. Thereafter, participants performed a cluster training session (CT) of equated load but with resting time distributed between each repetition. Dependent variables were recorded before, during, and after RE. Mean SBP (25·7 versus 10·9% percentage increase; P = 0·016) and RPP (112·5 versus 69·9%; P = 0·01) were significantly higher in TT. The decrease in HRV after exercise and the drop of HRC during exercise were similar in CT and TT. Change of standard deviation of normal RR intervals after TT correlated with change in SBP (r = 0·803; P = 0·009) while the change of Sample Entropy during exercise correlated with the increment of RPP during CT (ρ = -0·667; P = 0·05). This study suggests that set configuration influences acute cardiovascular responses during RE. When intensity, volume and work-to-rest ratio are equated, CT is less demanding in terms of SBP and RPP. A greater hemodynamic response during exercise would be associated with a faster parasympathetic recovery.

Verification criteria for the determination of Vo2 MAX in the field.

The purpose of this study was to evaluate if a verification test (VT) performed in the field offers more confident results than do traditional criteria in the determination of maximal oxygen uptake ((Equation is included in full-text article.)). Twelve amateur runners (age, 36.6 ± 6.6 years) performed a maximal graded field test and after 15 minutes of passive recovery a supramaximal test to exhaustion at 105% of their velocity associated with (Equation is included in full-text article.)(v(Equation is included in full-text article.)). Traditional criteria and 2 different verification criteria were evaluated. Verification criteria were (a) maximal oxygen uptake achieved in the VT ((Equation is included in full-text article.)) must be ≤5% higher than (Equation is included in full-text article.), and (b) no significant differences of means between tests. All participants met the first verification criterion although significant differences were found between (Equation is included in full-text article.)and (Equation is included in full-text article.)(59.4 ± 5.1 vs. 56.2 ± 4.7 ml·kg·min, p < 0.01). The criteria for the plateau, peak heart rate (HRpeak), maximum respiratory exchange ratio (RERmax), and maximum blood lactate concentration ([La]max) were satisfied by 75, 66, 92, and 66 of the participants, respectively. Kappa coefficients gave a significant and substantial agreement beyond chance between traditional criteria (p < 0.001). Despite the substantial agreement, traditional criteria induced the rejection of participants that might have achieved a true (Equation is included in full-text article.)with HRpeak and [La]max being the more stringent criteria for amateur runners. A verification protocol in the field using the criterion based on individual analysis is recommended.

Performance of maximum number of repetitions with cluster-set configuration.

PURPOSE: To analyze performance during the execution of a maximum number of repetitions (MNR) in a cluster-set configuration. METHOD: Nine judokas performed 2 sessions of parallel squats with a load corresponding to 4-repetition maximum (4RM) with a traditional-training (TT) and cluster-training (CT) set configuration. The TT consisted of 3 sets of repetitions leading to failure and 3 min of rest between sets. In the CT the MNR was performed with a rest interval between repetitions (45.44 ± 11.89 s). The work-to-rest ratio was similar for CT and TT. RESULTS: MNR in CT was 45.5 ± 32 repetitions and was 9.33 ± 1.87 times the volume in TT. There was a tendency for the average mean propulsive velocity (MPV) to be higher in CT (0.39 ± 0.04 vs 0.36 ± 0.04 m/s for CT and TT, respectively, P = .054, standardized mean difference [d] = 0.57). The average MPV was higher in CT for a similar number of repetitions (0.44 ± 0.08 vs 0.36 ± 0.04 m/s for CT and TT, respectively, P = .006, d = 1.33). The number of repetitions in TT was correlated with absolute 4RM load (r = -.719, P = .031) but not in CT (r = -.273, P = .477). CONCLUSIONS: A cluster-set configuration allows for a higher number of repetitions and improved sustainability of mechanical performance. CT, unlike TT, was not affected by absolute load, suggesting an improvement of training volume with high absolute loads.