Effects of reduced-volume of sprint interval training and the time course of physiological and performance adaptations

This study sought to determine the time course of training adaptations to two different sprint interval training programmes with the same sprint: rest ratio (1:8) but different sprint duration. Nine participants (M: 7; F: 2) were assigned to 15-s training group (15TG) consisting of 4 to 6 x 15-s sprints interspersed with 2-min recovery, whereas eight participants (M: 5; F: 3) were assigned to 30-s training group (30TG) consisting of 4 to 6 30-s sprints interspersed with 4-min recovery. Both groups performed their respective training twice per week over 9 weeks and changes in peak oxygen uptake (V̇O2peak) and time to exhaustion (TTE) were assessed every 3 weeks. Additional 8 healthy active adults (M: 6; F: 2) completed the performance assessments 9 weeks apart without performing training (control group, CON). Following 9 weeks of training, both groups improved V̇O2peak (15TG: 12.1%; 30TG: 12.8%, P < 0.05) and TTE (15TG: 16.2%; 30TG: 12.8%, P < 0.01) to a similar extent. However, while both groups showed the greatest gains in V̇O2peak at 3 weeks (15TG: 16.6%; 30TG: 17.0%, P < 0.001), those in TTE were greatest at 9 weeks. CON did not change any of performance variables following 9 weeks. This study demonstrated that whilst the changes in cardiorespiratory function plateau within several weeks with sprint interval training, endurance capacity (TTE) is more sensitive to such training over a longer time frame in moderately-trained individuals. Furthermore, a 50% reduction in sprint duration does not diminish overall training adaptations over 9 weeks

Influence of recovery intensity on oxygen demand and repeated sprint performance

AIM: This study aimed to determine effects of recovery intensity (passive, 20, 30 and 40%V̇ O2peak) on oxygen uptake kinetics, performance and blood lactate accumulation during repeated sprints. METHODS: 7 moderately-trained male participants (V̇O2peak: 48.1 ± 5.1 ml·kg-1·min-1) performed 4 x 30-s repeated Wingate tests on 4 separate occasions. RESULTS: Recovery of V̇ O2 between sprints was prolonged with recovery intensity (time required to reach 50% V̇O2peak: Passive: 50 ± 9; 20%: 81 ± 17; 30%: 130 ± 43; 40%: 188 ± 62 sec, P<0.001), while V̇O2-to-sprint work ratio was mainly increased by the higher intensities (Passive: 138 ± 17; 20%: 149 ± 14; 30%: 159 ± 15; 40%: 158 ± 17 ml·min-1·kJ-1, P=0.001). The decline in peak power tended to be greater in the higher intensity conditions during sprint 2 (Passive: 7.4 ± 5.4; 20%: 5.8 ± 7.9; 30%: 12.7 ± 7.4; 40%: 12.7 ± 5.5%, P=0.052), whereas average power was less decreased with recovery intensity during sprint 4 (Passive: 22.4 ± 8.9; 20%: 19.9 ± 6.1; 30%: 18.4 ± 7.3; 40%: 16.6 ± 6.2%, P=0.036). Blood lactate was not different with recovery intensity (P=0.251). CONCLUSION: The present study demonstrated that while the higher recovery intensities induce prolonged oxygen recovery and impaired peak power restoration during the initial sprints, those intensities provide a greater aerobic contribution to sprint performance, resulting in better power maintenance during the latter sprints

Active recovery induces greater endurance adaptations when performing sprint interval training

This study sought to determine effects of recovery intensity on endurance adaptations during sprint interval training (SIT). Fourteen healthy young adults (male: 9 and female: 5) were allocated to 1 of 2 training groups: active recovery group (ARG, male: 4 and female: 3) or passive recovery group (PRG, male: 5 and female: 2). After having completed a 2-week control period, both groups performed 6 sessions of 4- to 6 30-second sprints interspersed with 4-minute recovery over 2 weeks. However, only ARG cycled at 40% V[Combining Dot Above]O2peak during the 4-minute recovery periods, while PRG rested on the bike or cycled unloaded. After the 2-week training intervention, both groups improved 10-km time-trial performance to a similar extent (ARG: 8.6%, d = 1.60, p = 0.006; PRG: 6.7%, d = 0.96, p = 0.048) without gains in V[Combining Dot Above]O2peak. However, critical power was increased by ARG only (7.9%, d = 1.75, p = 0.015) with a tendency of increased maximal incremental power output (5.3%, d = 0.88, p = 0.063). During the training, active recovery maintained V[Combining Dot Above]O2 and heart rate at a higher level compared with passive recovery (V[Combining Dot Above]O2: p = 0.005, HR: p = 0.018), suggesting greater cardiorespiratory demands with the active recovery. This study demonstrated that greater endurance performance adaptations are induced with active recovery when performing SIT over a short time frame. The findings of the current study indicate that, with active recovery, individuals can gain greater training benefits without increasing total training commitment time. Further studies are required to determine whether differences are seen with recovery intensity over a longer period

Improved insulin sensitivity following a short-term whole body vibration intervention

Background and Objective: Despite being recommended for reducing the risk of type 2 diabetes (T2D) the majority of the population do not partake in the advised amount of regular exercise. While high intensity type training has been shown to produce improvements in insulin sensitivity its uptake in high risk populations has been questioned. Contrastingly, whole body vibration training (WBVT) is reported to benefit a range of outcomes in a variety of populations. Limited data exists regarding this training modality on insulin sensitivity. Current study assessed the effect of WBVT on oral glucose tolerance response. Method: Following institutional ethics approval, five young healthy sedentary individuals undertook oral glucose tolerance test (OGTT) prior to and on completion of 5-week progressive WBVT. Result: There were no changes in fasting plasma glucose concentrations before and after the 6 weeks of WBVT. Both pre- and post-training OGTT revealed no significant changes in plasma glucose concentrations over time. There was a 9% reduction in plasma glucose area under the curve (AUC) post training. The Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) decreased by 21% and Cederholm index of insulin sensitivity was increased by 18% following WBVT. Conclusion: Results suggest WBVT is associated with improved insulin sensitivity and could produce clinically relevant effects on fat metabolism in sedentary young people. Large-scale studies are now necessary to assess the effectiveness of WBVT in diabetic populations

Effects of in-season uphill sprinting on physical characteristics in semi-professional soccer players

AIM: Soccer performance is determined by a number of physiological adaptations that can be altered by high intensity training. However, the effectiveness of using an uphill sprint based protocol has not been demonstrated for soccer players. We sought to determine the effectiveness of an in-season uphill sprint training (UST) programme on soccer related physiological outcomes. METHODS: 14 male soccer players (age: 22 ± 8 years, height: 1.81 ± 8 m, body mass: 76 ± 12 kg) underwent testing (5-10-5 agility drill, Yo-Yo Intermittent Recovery Test Level 1, leg and back dynamometry & 3km time trial) at baseline and after 6 weeks of UST or normal activity. Participants were allocated to a control (n=7) or UST (n=7) group. The UST group took part in twice weekly training consisting of 10 x 10 sec sprints with 60s recovery on a 7% gradient for 6 weeks. The control group maintained normal activity patterns. RESULTS: 3km time trial, strength, agility and Yo-Yo performance were all significantly improved pre to post following 6 weeks of UST (Agility 3%, d=1.3; Strength 10%, d=-3.2; VO2 max 3%, d=-1.4; 3-km TT 4%, d=1.3). In the control group 3km time trial, strength, agility and Yo-Yo performance remained unchanged after 6 weeks (Agility 0.1%, d=-0.2; Strength 2%, d=0.0; VO2 max -0.1%, d=0.0; 3-km TT 1.3%, d=0.3). CONCLUSION: Therefore in-season short duration UST is an effective way to improve soccer fitness in a time efficient manner

Efficacy of a four-week uphill sprint training intervention in field hockey players

Current evidence increasingly suggests that very short, supra-maximal bouts of exercise can have significant health and performance benefits. The majority of research conducted in the area however, uses laboratory-based protocols, which can lack ecological validity. The purpose of this study was to examine the effects of a high intensity sprint-training programme on hockey related performance measures. 14 semi-professional hockey players completed either a 4-week high intensity training (HIT) intervention, consisting of a total of six sessions HIT, which progressively increased in volume (n=7), or followed their normal training programme (Con; n=7). Straight-line sprint speed with and without a hockey stick and ball, and slalom sprint speed, with and without a hockey stick and ball were used as performance indicators. Maximal sprint speed over 22.9m was also assessed. Upon completion of the four-week intervention, straight-line sprint speed improved significantly in the HIT group (~3%), with no change in performance for the Con group. Slalom sprint speed, both with and without a hockey ball was not significantly different following the training programme in either group. Maximal sprint speed improved significantly (12.1%) in the HIT group, but there was no significant performance change in the Con group. The findings of this study indicate that a short period of HIT can significantly improve hockey related performance measures, and could be beneficial to athletes and coaches in field settings

Experience with and Perceptions of Immigrants in Italy

This research explores Italians’ experiences with and perceptions of immigrants, along with their ideas of how the government should formulate immigration policy. Using in person surveys, 117 subjects were interviewed in the northern, central and southern regions of Italy. After accounting for variables like age, gender, and region, the data revealed interesting trends. Overall, the main findings of this study hold that there is a connection between the proximity of a subject’s relationship with immigrants and how positive their experiences are. These experiences can influence how the subject then views immigrants as either an advantage or a disadvantage, however, other factors like culture and economy, also play important roles. Finally, most subjects recognized the failures of the Italian government to properly handle immigration reform and generally favored the idea of increasing restrictions on who could enter the country

Early adaptations to a two-week uphill run sprint interval training and cycle sprint interval training

This study sought to compare early physiological and performance adaptations between a two-week cycle sprint interval training (SIT) and uphill run sprint training (UST) programs. Seventeen recreationally active adult males (age = 28 ± 5 years; body mass (BM) = 78 ± 9 kg) were assigned to either a control (n = 5), SIT (n = 6), or UST (n = 6) group. A discrete group of participants (n = 6, age = 33 ± 6 years, and body mass = 80 ± 9 kg) completed both training protocols to determine acute physiological responses. Intervention groups completed either a run or cycle peak oxygen uptake (VO2peak) test (intervention type dependent) prior to and following two weeks of training. Training comprised of three sessions per week of 4 × 30-s “all-out” sprints with a four-minute active recovery between bouts on a cycle ergometer against 7.5% of body mass in the SIT group and on a 10% slope in the UST group. The VO2peak values remained unchanged in both training groups, but time-to-exhaustion (TTE) was significantly increased only in the UST group (pre—495 ± 40 s, post—551 ± 15 s; p = 0.014) and not in the SIT group (pre—613 ± 130 s, post—634 ± 118 s, p = 0.07). Ventilatory threshold (VT) was significantly increased in both training groups (SIT group: pre—1.94 ± 0.45 L·min−1, post—2.23 ± 0.42 L·min−1; p < 0.005, UST group: pre—2.04 ± 0.40 L·min−1, post—2.33 ± 0.34 L·min−1, p < 0.005). These results indicate that UST may be an effective alternative to SIT in healthy individuals

Cardiorespiratory fitness and aerobic performance adaptations to a 4-week sprint interval training in young healthy untrained females

Purpose: The aim of this study was to test the effects of sprint interval training (SIT) on cardiorespiratory fitness and aerobic performance measures in young females.Methods: Eight healthy, untrained females (age 21 ± 1 years; height 165 ± 5 cm; body mass 63 ± 6 kg) completed cycling peak oxygen uptake ( V˙O2V˙O2  peak), 10-km cycling time trial (TT) and critical power (CP) tests pre- and post-SIT. SIT protocol included 4 × 30-s “all-out” cycling efforts against 7 % body mass interspersed with 4 min of active recovery performed twice per week for 4 weeks (eight sessions in total).Results: There was no significant difference in  V˙O2V˙O2  peak following SIT compared to the control period (control period: 31.7 ± 3.0 ml kg−1 min−1; post-SIT: 30.9 ± 4.5 ml kg−1 min−1; p > 0.05), but SIT significantly improved time to exhaustion (TTE) (control period: 710 ± 101 s; post-SIT: 798 ± 127 s; p = 0.00), 10-km cycling TT (control period: 1055 ± 129 s; post-SIT: 997 ± 110 s; p = 0.004) and CP (control period: 1.8 ± 0.3 W kg−1; post-SIT: 2.3 ± 0.6 W kg−1; p = 0.01).Conclusions: These results demonstrate that young untrained females are responsive to SIT as measured by TTE, 10-km cycling TT and CP tests. However, eight sessions of SIT over 4 weeks are not enough to provide sufficient training stimulus to increase  V˙O2V˙O2  peak

High-intensity cycling training:the effect of work-to-rest intervals on running performance measures

The work-to-rest ratio during cycling-based high-intensity interval training (HIT) could be important in regulating physiological and performance adaptations. We sought to determine the effectiveness of cycling-based HIT with different work-to-rest ratios for long-distance running. Thirty-two long-distance runners (age: 39 ± 8 years; sex: 14 men, 18 women; average weekly running training volume: 25 miles) underwent baseline testing (3-km time-trial, V[Combining Dot Above]O2peak and time to exhaustion, and Wingate test) before a 2-week matched-work cycling HIT of 6 × 10-second sprints with different rest periods (30 seconds [R30], 80 seconds [R80], 120 seconds [R120], or control). Three-kilometer time trial was significantly improved in the R30 group only (3.1 ± 4.0%, p = 0.04), whereas time to exhaustion was significantly increased in the 2 groups with a lower work-to-rest ratio (R30 group 6.4 ± 6.3%, p = 0.003 vs. R80 group 4.4 ± 2.7%, p = 0.03 vs. R120 group 1.9 ± 5.0%, p = 0.2). However, improvements in average power production were significantly greater with a higher work-to-rest ratio (R30 group 0.3 ± 4.1%, p = 0.8 vs. R80 group 4.6 ± 4.2%, p = 0.03 vs. R120 group 5.3 ± 5.9%, p = 0.02), whereas peak power significantly increased only in the R80 group (8.5 ± 8.2%, p = 0.04) but not in the R30 group (4.3 ± 6.1%, p = 0.3) or in the R120 group (7.1 ± 7.9%, p = 0.09). Therefore, cycling-based HIT is an effective way to improve running performance, and the type and magnitude of adaptation is dependent on the work-to-rest ratio