High-volume Protocol Research Articles

Effects of Different Levels of Fatigue on Vertical Jump Performance, Vertical Stiffness, and Intralimb Coordination

This study aimed to investigate the acute effects of different levels of muscular fatigue on vertical jump perfor- mance, vertical stiffness, and intralimb coordination. Seventeen physically active men performed two fatigue protocols (low volume and high volume) composed of continuous vertical jumps on separate weeks. Jump height, vertical stiffness, and intralimb coordination were measured during countermovement vertical jumps prior to and immediately following the fatigue protocols. The jumps were performed on a force plate and filmed with high-speed cameras. The continuous relative phase was calculated as a measure of intralimb coordination. Mixed-model ANOVA was used to compare the variables between conditions and times. The fatigue index was greater in the high-volume protocol (27±12%) than in the low-volume protocol (16±7%). Jump height decreased (p≤0.01) after the high-volume protocol. Vertical stiffness decreased (p=0.05), and the continuous relative phase of thigh-shank coupling in the ascent phase of countermovement jumps increased (p=0.04) after both proto- cols. In conclusion, jump performance was only affected by higher fatigue indexes, while vertical stiffness and intralimb coordination were affected similarly irrespective of the fatigue levels.

The Effects of Low Volume Versus High Volume Sled-Push Training on Muscular Adaptation

PURPOSE: This study aimed to compare the effects of low-volume and high-volume sled-push resistance training on muscle strength, power, and body composition.METHODS: Twenty-four college students were recruited and matched based on baseline one-repetition maximum (1-RM) into one of the three groups: 1) low volume (LV) resistance training, 2) high volume (HV) resistance training, or 3) control (CON) (n=8 per group). The LV training consisted of five single repetitions of pushing a weighted sled for 9.1 m. The HV training consisted of three sets of five repetitions of pushing a weighted sled for 9.1 m. Training consisted of three weekly workouts performed on nonconsecutive days for 6 weeks. This study utilized a pre-test and post-test design consisting of 1-RM, Wingate power test, standing long jump, vertical jump, and body composition.RESULTS: After 6 weeks of training, there was a similar but significant increase in 1-RM in both training groups (pre-test: LV=226.8±14.8 kg vs. HV=217.7±19.5 kg; post-test: LV=298.5±15 kg vs. HV=286.9±16 kg, <i>p</i><.001). However, no improvements were observed in the Wingate power test, standing long jump, vertical jump, or body composition in both training and CON groups (<i>p</i>>.05).CONCLUSIONS: The results suggested that low-volume resistance training was as effective as a high-volume protocol for improving muscle strength. However, the present study was unable to determine the effects on muscle power and body composition.

Effect of three different Pilates sessions on energy expenditure and aerobic metabolism in healthy females

The Pilates method has become a popular exercise modality. However, there is little information on the energy expenditure (EE) and aerobic metabolism involved in a Pilates session. This study aimed to compare the EE of three different types of Pilates sessions. Thirty-three sedentary women (22.03 ± 3.32 years old) performed three Pilates sessions: (1) a traditional session (TS): single set, low volume of repetitions, and long rest interval; (2) non-traditional session (NSS): single set, a high volume of repetitions, and short rest interval; and (3) non-traditional session (NMS): multiple sets and short rest interval. In each session, EE per minute (EE/min), total EE (TEE), oxygen consumption (V’O2), respiratory exchange ratio (RER), and metabolic equivalent were determined via a gas analyzer. Heart rate (HR) was measured via a HR monitor. Repeated measures two-way ANOVA (time × session) followed by Tukey test were used to compare differences in each variable for the sessions (P ≤ 0.05). When compared to the TS session, the non-traditional sessions resulted in greater EE/min, TEE, V’O2, RER, and mean HR (P < 0.001). TEE in NMS was also greater than NSS (P < 0.001). Our findings indicate that a non-traditional approach to Pilates, with multiple sets, high repetitions, and a shorter rest interval induces greater metabolic cost than a traditional Pilates session. However, the total caloric cost of high-volume protocols such as the NMS performed in this study is small compared to aerobic exercise and does not contribute significantly to daily EE.

Intramuscular MAPK signaling following high volume and high intensity resistance exercise protocols in trained men.

To examine the mitogen-activated protein kinase (MAPK) family of signaling proteins following typical high volume (HV) and high intensity (HI) lower body resistance exercise protocols in resistance-trained men. Ten resistance-trained men (24.7±3.4year; 90.1±11.3kg; 176.0±4.9cm) performed each resistance exercise protocol in a random, counterbalanced order. The HV protocol utilized a load of 70% 1-RM for sets of 10-12 repetitions with a 1-min rest period length between sets and exercises. The HI protocol utilized a load of 90% 1-RM for sets of 3-5 repetitions with a 3-min rest period length between sets and exercises. Both protocols included six sets of barbell back squats and four sets of bilateral leg press, bilateral hamstring curls, bilateral leg extensions, and seated calf raises. Fine needle muscle biopsies of the vastus lateralis were completed at baseline (BL) and 1-h post exercise (1H). No significant differences over time were noted for phosphorylation of MEK1, ERK1/2, p38, MSK1, ATF2, p53, or c-Jun (p>0.05). No significance between trial interactions was noted for phosphorylation of MAPK signaling proteins, including MEK1, ERK1/2, p38, JNK, MSK1, ATF2, STAT1, p53, c-Jun, or HSP27 (p>0.05). However, significant time effects were observed for phosphorylation of JNK (p<0.01), HSP27 (p<0.01), and STAT1 (p=0.03). Phosphorylation of JNK, HSP27, and STAT1 was significantly elevated from BL at 1H for both HV and HI. HV and HI lower body resistance exercise protocols appear to elicit similar MAPK activation in resistance-trained men.

MAPK Signaling Following High Volume And High Intensity Resistance Exercise Protocols In Trained Men

Resistance exercise initiates a multifaceted series of events converting the stimulus of muscle contraction into biochemical responses regulating the rate of protein synthesis. The MAPK pathway appears to be a key signaling pathway involved in the regulation of skeletal muscle mass. While resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, it is unknown whether these protocols differentially stimulate MAPK signaling. PURPOSE: The purpose of this study was to examine MAPK signaling proteins following a typical HV and HI lower-body resistance exercise protocol. METHODS: Ten resistance-trained men (24.7±3.4y; 90.1±11.3kg; 176.0±4.9cm) performed each resistance exercise protocol in a random, counterbalanced order. The HV protocol utilized a load of 70% 1-RM for sets of 10-12 repetitions with a 1-minute rest period length between sets and exercises. The HI protocol utilized a load of 90% 1-RM for sets of 3-5 repetitions with a 3-minute rest period length between sets and exercises. Both protocols included six sets of barbell back squats and four sets of bilateral leg press, bilateral hamstring curls, bilateral leg extensions, and seated calf raises. Fine needle muscle biopsies of the vastus lateralis were completed at baseline (BL) and 1-hour post exercise (1H). RESULTS: No significant differences over time were noted for phosphorylation of ATF, ERK/MAPK, p53, p38, MEK1, MSK1, or c-Jun (p>0.05). No significant between trial interactions were noted for phosphorylation of ATF2, JNK, HSP27, ERK/MAPK, p53, p38, MEK1, MSK1, STAT1, or c-Jun (p>0.05). However, significant time effects were observed for phosphorylation of JNK (p=0.0001), HSP27 (p=0.002), and STAT1 (p=0.03). Phosphorylation of JNK, HSP27, and STAT1 were significantly elevated from BL at 1H for both HV and HI. CONCLUSION: HV and HI lower-body resistance exercise protocols appear to elicit similar MAPK activation in resistance-trained men.

The Acute Effects of Manipulating Volume and Load of Back Squats on Countermovement Vertical Jump Performance

The acute effects of manipulating the volume and load of back squats on subsequent countermovement vertical jump performance were investigated in the present study. Eleven National Collegiate Athletic Association division II female volleyball players performed 10 countermovement vertical jumps (CMJs) on a force platform 2 minutes after the last squat repetition of a high-load (HL) or high-volume (HV) squat protocol. Two minutes of rest was provided between each CMJ. The HL protocol culminated in the subjects having to perform 3 repetitions with a load equivalent to 90% 1 repetition maximum (1RM) back squat, whereas 12 repetitions with a load equivalent to 37% 1RM were performed in the HV protocol. During an initial familiarization session, knee angles were recorded during a series of CMJs, and these angles were used to control the depth of descent during all subsequent back squats. Jump height (JH) and vertical stiffness (VStiff) were calculated during each of the 10 CMJ, and the change in these variables after the 2 squat protocols was assessed using an analysis of variance model with repeated measures on 2 factors (Protocol [2-levels]; Time [2-levels]). There was no significant difference in JH after the HL and HV protocols (p > 0.05). A significant Protocol × Time interaction for VStiff resulted from the increase after the HL protocol being greater than that after the HV protocol (p = 0.03). The knee angles before the HL and HV protocols were significantly greater than those measured during the initial familiarization session (p = 0.001). Although neither squat protocol provided any benefit in improving JH, the heavy squat protocol produced greater increases in VStiff during the CMJ. Because of the increased VStiff caused by the HL protocol, volleyball coaches may consider using such protocols with their players to improve performance in jumps performed from a run such as the spike and on-court agility.

Effects of Low- and High-Volume Stretching on Bench Press Performance in Collegiate Football Players

The purpose of this study was to determine the effects of acute low- and high-volume static and proprioceptive neuromuscular facilitation (PNF) stretching on 1-repetition maximum (1RM) bench press. Fifteen healthy male National Collegiate Athletic Association Division II football players (age: 19.9 +/- 1.1 years; weight: 98.89 +/- 13.39 kg; height: 184.2 +/- 5.7 cm; body composition: 14.6 +/- 7.4%; and 1RM bench press: 129.7 +/- 3.3 kg) volunteered to participate in the study. Subjects completed 5 different stretching protocols integrated with a 1RM dynamic warm-up routine followed by 1RM testing in randomly assigned order. The protocols included (a) nonstretching (NS), (b) low-volume PNF stretching (LVPNFS), (c) high-volume PNF stretching (HVPNFS), (d) low-volume static stretching (LVSS), and (d) high-volume static stretching (HVSS). Two and 5 sets of stretching were completed for the low- and high-volume protocols, respectively. The stretching protocols targeted triceps and chest/shoulder muscle groups using 2 separate exercises. There were no significant differences in 1RM bench press performance (p > 0.05) among any of the stretching protocols NS (129.7 +/- 3.3 kg), LVPNFS (128.9 +/- 3.8 kg), HVPNFS (128.3 +/- 3.7 kg), LVSS (129.7 +/- 3.7 kg), and HVSS (128.2 +/- 3.7 kg). We conclude that low- and high-volume PNF and static stretching have no significant acute effect on 1RM bench press in resistance-trained collegiate football players. This suggests that resistance-trained athletes can include either (a) a dynamic warm-up with no stretching or (b) a dynamic warm-up in concert with low- or high-volume static or PNF flexibility exercises before maximal upper body isotonic resistance-training lifts, if adequate rest is allowed before performance.

Effects Of Low And High Volume Stretching On Bench Press Performance In Collegiate Football Players

Maximal muscular force production has been shown to be attenuated when preceded by acute static stretching (Power, K. et al., Med. Sci. Sport Exerc. 36:1389-1396, 2004) however, it is unclear whether varying stretching volume and method has variable effects on muscular strength in trained athletes. PURPOSE: To determine the effects of acute low and high volume static and proprioceptive neuromuscular facilitation (PNF) stretching on one-repetition maximum (1RM) bench press in NCAA Division II collegiate football players. METHODS: Fifteen (n = 15) resistance trained male football players (mean ± SD; age: 19.9 ± 1.1 y; weight: 98.89 ± 13.39 kg; height: 184.2 ± 5.7 cm; body composition: 14.6 ± 7.4 %) volunteered to participate in the study. Subjects were randomly assigned to each of 5 stretching protocols to include: 1) low volume PNF stretching (LVPNFS), 2) high volume PNF stretching (HVPNFS), 3) low volume static stretching (LVSS), 4) high volume static stretching (HVSS), and 5) non-stretching (NS) prior to 1RM testing. Two and 5 sets of stretching were completed for the low and high volume protocols respectively. The PNF stretching protocols used a contract (5 sec at 75% maximum effort) - relax (10 sec) - stretch (10 sec at moderate tension) sequence that targeted triceps and chest muscle groups using two separate exercises. The static stretching protocols targeted the same muscle groups and were passively held to a point of moderate tension for 20 and 30 sec for LVSS and HVSS respectively. The stretching interventions were substituted for the stretching recommendations outlined in the ACSM 1RM resistance training guidelines (2000). A minimum of 48 h was required between testing sessions. RESULTS: One-Way ANOVA analysis with repeated measures indicated there was no significant effect (p>0.05) of any of the stretching protocols LVPNFS (128.9 + 3.8 kg), HVPNFS (128.3 + 3.7 kg), LVSS (129.7 + 3.7 kg), HVSS (128.2 + 3.7 kg) and NS (129.7 + 3.3 kg) on 1RM bench press performance. CONCLUSION: We conclude that low and high volume PNF and static stretching has no significant acute effect on 1RM bench press in resistance trained collegiate football players. This suggests that resistance trained athletes can perform either low or high volume static or PNF flexibility exercises prior to 1 RM assessments without adversely affecting performance.

Multislice CT angiography

Multislice CT has overcome past limitations of CT angiography (CTA): Scan length and spatial resolution can be simultaneously optimized with multislice CTA, contrast medium can be saved, and the evaluation of large anatomic areas and vessels smaller than 1 mm become possible. This article describes how to optimize scanning protocols and contrast injection, and discusses the main clinical applications of this new technique. Only three main scanning protocolssuffice for all indications. A high speed / high-volume protocol (using 4*2mm or 4*2.5mm collimation) can be employed to scan the chest or abdomen in 8-10s, or to cover the whole abdominal aorta and the peripheral runoff including the feet within 40-65s. A high resolution protocol (using 4*1mm or 4*1.25mm) can be employed for the aorta and most regional vascular beds. It allows for near isotrophic imaging and depicts fine vascular structures with excellent detail. Ultra-high resolution protocols (using 2*0.5mm or 4*0.5mm collimation) yield totally isotropic data sets, and are mainly reserved for cerebrovascular imaging. Image processing techniques, and, in particular, volume rendering have made image presentation faster and easier. Multislice CTA exceeds MRA in spatial resolution and is now able to display even small vascular side branches. Its main indications will be aortic diseases, suspected pulmonary embolism but also renal artery stenoses, preoperative workup of abdominal or cerebral vessels, and acute vascular diseases. Multisplice CTA will become a strong competitor of other minimally invasive vascular imaging techniques.