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Studies investigating the acute effect of postprandial exercise (PPE) on glucose responses exhibit significant heterogeneity in terms of participant demographic, exercise protocol, and exercise timing post-meal. As such, this study aimed to further analyze the existing literature on the impact of PPE on glycemic control in overweight individuals and individuals with obesity and type 2 diabetes (T2DM). A literature search was conducted through databases such as PubMed, CINAHL, and Google Scholar. Thirty-one original research studies that met the inclusion criteria were selected. A random-effect meta-analysis was performed to compare postprandial glucose area under the curve (AUC) and 24 h mean glucose levels between PPE and the time-matched no-exercise control (CON). Subgroup analyses were conducted to explore whether the glucose-lowering effect of PPE could be influenced by exercise duration, exercise timing post-meal, and the disease status of participants. This study revealed a significantly reduced glucose AUC (Hedges' g = −0.317; SE = 0.057; p < 0.05) and 24 h mean glucose levels (Hedges' g = −0.328; SE = 0.062; p < 0.05) following PPE compared to CON. The reduction in glucose AUC was greater (p < 0.05) following PPE lasting >30 min compared to ≤30 min. The reduction in 24 h mean glucose levels was also greater (p < 0.05) following PPE for ≥60 min compared to <60 min post-meal and in those with T2DM compared to those without T2DM. PPE offers a viable approach for glucose management and can be performed in various forms so long as exercise duration is sufficient. The glucose-lowering effect of PPE may be further enhanced by initiating it after the first hour post-meal. PPE is a promising strategy, particularly for patients with T2DM. This manuscript is registered with Research Registry (UIN: reviewregistry1693). [ABSTRACT FROM AUTHOR]

The time-of-day effect of exercise on human function remains largely equivocal. Hence, this study aimed to further analyze the existing evidence concerning diurnal variations in cardiorespiratory responses and endurance performance using a meta-analytic approach. Literature search was conducted through databases, including PubMed, CINAHL, and Google Scholar. Article selection was made based on inclusion criteria concerning subjects' characteristics, exercise protocols, times of testing, and targeted dependent variables. Results on oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio, and endurance performance in the morning (AM) and late afternoon or evening (PM) were extracted from the chosen studies. Metaanalysis was conducted with the random-effects model. Thirty-one original research studies that met the inclusion criteria were selected. Meta-analysis revealed higher resting VO2 (Hedges' g = -0.574; p = 0.040) and resting HR (Hedges' g= -1.058; p = 0.002) in PM than in AM. During exercise, although VO2 remained indifferent between AM and PM, HR was higher in PM at submaximal (Hedges' g = -0.199; p = 0.046) and maximal (Hedges' g = -0.298; p = 0.001) levels. Endurance performance as measured by time-to-exhaustion or the total work accomplished was higher in PM than in AM (Hedges' g = -0.654; p = 0.001). Diurnal variations in VO2 appear less detectable during aerobic exercise. The finding that exercising HR and endurance performance were greater inPMthan in AMemphasizes the need to consider the effect of circadian rhythm when evaluating athletic performance or using HR as a criterion to assess fitness or monitor training. [ABSTRACT FROM AUTHOR]

Time restricted feeding (TRF) as a form of intermittent fasting (IF) has gained popularity because its ability to reduce body mass (BM) without an emphasis on caloric restriction. However, how this dietary protocol may affect health, fitness, and performance in a relatively healthy cohort remains less clear. The purpose of this article was to systematically review the current literature concerning the effect of TRF on anthropometric, metabolic, and fitness parameters in normal-weight adults and overweight and obese individuals. A systematic search of English literature was conducted through databases including PubMed, CINAHL, and Google Scholar. The search was facilitated by using various combinations of key words related to nutritional interventions, i.e., IF and TRF, and outcomes of interest, i.e., BM, body composition, glucose, insulin, lipid, fitness, and performance. The article selection was made based on the inclusion and exclusion criteria concerning the participants' characteristics, study design, intervention protocols, and targeted dependent variables. Twenty-three full-text longitudinal randomized and nonrandomized controlled studies were selected for this review. Our analysis indicates that TRF can reduce BM and improve nutrient metabolism in both normal- and over-weight individuals. TRF does not appear to alter protein synthesis and fat-free mass nor hamper aerobic fitness and muscular performance among physically active individuals including athletes. In conclusion, TRF as a more easily adaptable form of IF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function. However, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power. Time-restricted feeding (TRF) differs from other fasting protocols due to its emphasis on restricting eating window rather than caloric intake and can be more easily adopted by simply skipping a meal. Its deemphasis on caloric restriction appeals to many young and physically active individuals wanting to optimize body composition but needing sufficient energy to support their physical training and daily activity. Much of what is known regarding the impact of TRF on fitness and athletic performance was derived from studies that use the Ramadan fasting protocol, which differs from TRF in terms of protocol duration and feeding schedule. This review concludes that TRF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function in both normal- and over-weight individuals. Due to limited evidence concerning TRF and athletic performance, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power. [ABSTRACT FROM AUTHOR]

The purpose of this descriptive investigation was to characterize a group of elite strongman competitors to document the body composition of this unique population of strength athletes. Data were collected from eligible competitors as part of a health screening program conducted over 5 consecutive years. Imaging was acquired using dual-energy x-ray absorptiometry (DXA), providing total body measures of fat mass, lean mass, and bone mineral content (BMC). Year to year, testing groups showed a homogenous grouping of anthropometric, body composition, and bone density metrics. Composite averages were calculated to provide an anthropometric profile of the elite strongman competitor (N = 18; mean ± SD): age, 33.0 ± 5.2 years; body height, 187.4 ± 7.1 cm; body mass, 152.9 ± 19.3 kg; body mass index, 43.5 ± 4.8 kg·m-2; fat mass, 30.9 ± 11.1 kg; lean mass, 118.0 ± 11.7 kg, body fat, 18.7 ± 6.2%, total BMC, 5.23 ± 0.41 kg, and bone mineral density, 1.78 ± 0.14 g·cm-2. These data demonstrate that elite strongman competitors are among the largest human male athletes, and in some cases, they are at the extreme limits reported for body size and structure. Elite strongman competitors undergo a high degree of mechanical stress, providing further insight into the potent role of physical training in mediating structural remodeling even into adulthood. Such data provide a glimpse into a unique group of competitive athletes pushing the limits not only of human performance but also of human physiology. [ABSTRACT FROM AUTHOR]

Ketogenic diets (KDs) have received increasing attention among athletes and physically active individuals. However, the question as to whether and how the diet could benefit this healthy cohort remains unclear.Purpose: This study was designed to systematically review the existing evidence concerning the effect of KDs on body composition, aerobic and anaerobic capacity, muscle development, and sports performance in normal-weight individuals including athletes.Methods: A systematic search of English literature was conducted through electronic databases including PubMed, EBSCOhost, and Google Scholar. Upon the use of search criteria, 23 full-text original human studies involving non-obese participants were included in this review. For more stratified and focused analysis, these articles were further categorized based on the outcomes being examined including 1) body mass (BM) and %fat, 2) substrate utilization, 3) blood substrate and hormonal responses, 4) aerobic capacity and endurance performance, and 5) strength, power, and anaerobic capacity.Results: Our review indicates that a non-calorie-restricted KD carried out for ≥3 weeks can produce a modest reduction in BM and %fat, while maintaining fat-free mass. This diet leads to augmented use of fat as fuel, but this adaptation doesn't seem to improve endurance performance. Additionally, ad libitum KDs combined with resistance training will pose no harm to developing strength and power, especially when protein intake is increased modestly.Conclusions: It appears that a non-calorie-restricted KD provides minimal ergogenic benefits in normal-weight individuals including athletes, but can be used for optimizing BM and body composition without compromising aerobic and anaerobic performance. Key teaching pointsKetogenic diets have received increasing attention among athletes and physically active individuals.It remains elusive as to whether ketogenic diets could confer ergogenic benefits for those who are normal weight but want to use the diet to improve fitness and performance.An interesting dilemma exists in that ketogenic diets can reduce body mass and %fat and increase fat oxidation, but they can also decrease glycogen stores and limit sports performance.This review concludes that a non-calorie-restricted ketogenic diet provides minimal ergogenic benefits in normal-weight individuals, but can be used to optimize body mass and composition without compromising athletic performance.This finding can be important for esthetic or weight-sensitive athletes because the diet may allow them to reach a target body mass without having to sacrifice athletic performance.The ketogenic diet-induced metabolic adaptations require a state of ketosis, and thus caution should be taken because an excessive increase in ketone bodies can be detrimental to health. [ABSTRACT FROM AUTHOR]

Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although the specific hormonal influence must be considered within the context of the entire endocrine system and its relationship with other physiological systems, three key hormones are considered the "anabolic giants" in cellular growth and repair: testosterone, the growth hormone superfamily, and the insulin-like growth factor (IGF) superfamily. In addition to these anabolic hormones, glucocorticoids, mainly cortisol must also be considered because of their profound opposing influence on human skeletal muscle anabolism in many instances. This review presents emerging research on: (1) Testosterone signaling pathways, responses, and adaptations to resistance training; (2) Growth hormone: presents new complexity with exercise stress; (3) Current perspectives on IGF-I and physiological adaptations and complexity these hormones as related to training; and (4) Glucocorticoid roles in integrated communication for anabolic/catabolic signaling. Specifically, the review describes (1) Testosterone as the primary anabolic hormone, with an anabolic influence largely dictated primarily by genomic and possible non-genomic signaling, satellite cell activation, interaction with other anabolic signaling pathways, upregulation or downregulation of the androgen receptor, and potential roles in co-activators and transcriptional activity; (2) Differential influences of growth hormones depending on the "type" of the hormone being assayed and the magnitude of the physiological stress; (3) The exquisite regulation of IGF-1 by a family of binding proteins (IGFBPs 1–6), which can either stimulate or inhibit biological action depending on binding; and (4) Circadian patterning and newly discovered variants of glucocorticoid isoforms largely dictating glucocorticoid sensitivity and catabolic, muscle sparing, or pathological influence. The downstream integrated anabolic and catabolic mechanisms of these hormones not only affect the ability of skeletal muscle to generate force; they also have implications for pharmaceutical treatments, aging, and prevalent chronic conditions such as metabolic syndrome, insulin resistance, and hypertension. Thus, advances in our understanding of hormones that impact anabolic: catabolic processes have relevance for athletes and the general population, alike. [ABSTRACT FROM AUTHOR]

Objective: The present study aimed to examine the interactive effect of exercise and energy balance on energy expenditure and substrate utilization.Method: Seven men and 7 women underwent three 2-day experimental protocols in a random order. Each protocol consisted of no exercise (NE), exercise only (EO), or exercise with a matched energy replacement (ER) on day 1 followed by metabolic testing that occurred after a 12-hour overnight fasting on day 2. Both EO and ER involved treadmill running at 60% maximal oxygen uptake (VO2max) that induced an energy expenditure of ∼ 500 kcal. The replacement meal used in ER contained ∼ 500 kcal made up of 45% carbohydrate, 30% fat, and 25% protein. During metabolic testing, oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), and rates of carbohydrate (COX) and fat oxidation (FOX) were determined in three successive 15-minute periods including rest and exercise at 50% and 70% VO2max.Results: No differences in VO2 and HR were found at rest among NE, EO, and ER. However, RER was lower in EO than NE (0.840 ± 0.014 vs 0.889 ± 0.012, p < 0.05), COX (g·min-1) was lower in ER than NE (0.144 ± 0.016 vs 0.197 ± 0.019, p < 0.05), and FOX (g·min-1) was higher in EO or ER than NE (0.054 ± 0.010 or 0.057 ± 0.009 vs 0.034 ± 0.007, p < 0.05). No treatment effects were observed for all variables at either intensity.Conclusions: This study demonstrates that an exercise of moderate intensity can increase resting fat oxidation even when the exercise-induced energy expenditure is balanced by energy intake. This finding suggests that muscle action is vital in augmenting fat utilization. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of integrative neuromuscular training (INT) during physical education (PE) class on selected measures of health- and skill-related fitness in children. Forty children from two 2nd grade PE classes were cluster randomized into either an INT group (n = 21) or a control (CON) group (n = 19). INT was performed 2Ã/wk during the first ~15 min of each PE class and consisted of body weight exercises. INT and CON participants were assessed for health- and skill-related fitness before and after 8 wks of PE with or without INT, respectively. A significant interaction of group by time was observed in INT participants with improvements noted in push-ups, curl-ups, long jump, single leg hop, and 0.5 mile (0.8 km) run performance (p < .05). These data indicate that INT is an effective and time-efficient addition to PE as evidenced by improvements in health- and skill-related fitness measures in children. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of integrative neuromuscular training (INT) during physical education (PE) class on selected measures of health- and skill-related fitness in children. Forty children from two 2nd grade PE classes were cluster randomized into either an INT group (n = 21) or a control (CON) group (n = 19). INT was performed 2×/wk during the first ~15 min of each PE class and consisted of body weight exercises. INT and CON participants were assessed for health- and skill-related fitness before and after 8 wks of PE with or without INT, respectively. A significant interaction of group by time was observed in INT participants with improvements noted in push-ups, curl-ups, long jump, single leg hop, and 0.5 mile (0.8 km) run performance (p < .05). These data indicate that INT is an effective and time-efficient addition to PE as evidenced by improvements in health- and skill-related fitness measures in children. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the influence of recovery time following a dynamic warm-up (DY) and a static stretch warm-up (SS) on power performance in adolescent athletes. Following baseline measures, 19 males (16.5 ± 1.1 yrs) performed the vertical jump (VJ) and seated medicine ball toss (MB) at the following time points after DY and SS: 2, 6, 10, 14, 18, 22 min. Analysis of variance revealed that VJ was significantly greater following DY than SS at 2, 6, 10, 14 and 18 min. Main effects indicated a significant increase in VJ from baseline at 2 and 6 min following DY (2.6-3.9%) and a significant decrease in VJ from baseline at 2, 6, 10, 14 and 18 min following SS (-3.2% to -7.0%). No significant interaction effects between DY and SS were observed for MB. These findings indicate that lower body power performance in male adolescent athletes can be enhanced following DY as compared with SS during the first 18 min of the post warm-up period. [ABSTRACT FROM AUTHOR]

The effect of 10 wk of protein-supplement timing on strength, power, and body composition was examined in 33 resistance-trained men. Participants were randomly assigned to a protein supplement either provided in the morning and evening (n = 13) or provided immediately before and immediately after workouts (n = 13). In addition, 7 participants agreed to serve as a control group and did not use any protein or other nutritional supplement. During each testing session participants were assessed for strength (one-repetition-maximum [1RM] bench press and squat), power (5 repetitions performed at 80% of 1RM in both the bench press and the squat), and body composition. A significant main effect for all 3 groups in strength improvement was seen in 1RM bench press (120.6 ± 20.5 kg vs. 125.4 ± 16.7 at Week 0 and Week 10 testing, respectively) and 1RM squat (154.5 ± 28.4 kg vs. 169.0 ± 25.5 at Week 0 and Week 10 testing, respectively). However, no significant between-groups interactions were seen in 1RM squat or 1RM bench press. Significant main effects were also seen in both upper and lower body peak and mean power, but no significant differences were seen between groups. No changes in body mass or percent body fat were seen in any of the groups. Results indicate that the time of protein-supplement ingestion in resistance-trained athletes during a 10-wk training program does not provide any added benefit to strength, power, or body-composition changes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the lifting performance of boys (N = 12; age 11.3 ± 0.8 yr), teens (N = 13; age 13.6 ± 0.6 yr), and men (N = 17; age 21.4 ± 2.1 yr) to various rest interval (RI) lengths on the bench press exercise. Each subject performed 3 sets with a 10 repetition maximum load and a 1, 2, and 3 min RI between sets. Significant differences in lifting performance between age groups were observed within each RI for selected sets with boys and teens performing significantly more total repetitions than adults following protocols with 1 min (27.9 ± 3.1, 26.9 ± 3.9, and 18.2 ± 4.1, respectively), 2 min (29.6 ± 1.0, 27.8 ± 3.5, and 21.4 ± 4.1, respectively) and 3 min (30.0 ± 0.0, 28.8 ± 2.4, and 23.9 ± 5.3, respectively) RIs. Significant differences in average velocity and average power between age groups were also observed. These findings indicate that boys and teens are better able to maintain muscle performance during intermittent moderate-intensity resistance exercise as compared with men. [ABSTRACT FROM AUTHOR]

The authors aimed to examine the acute hormonal and performance responses to resistance exercise with and without prior consumption of an amino acid/creatine/energy supplement. Eight men performed a resistance-exercise protocol at baseline (BL), 20 min after consuming a supplement (S) consisting of essential amino acids, creatine, taurine, caffeine, and glucuronolactone or a maltodextrin placebo (P). Venous blood samples were obtained before and immediately after (IP), 15 min (15P), and 30 min (30P) after each protocol. Area under the curve of resistance-exercise volume revealed that BL was significantly less than S (10%) and P (8.6%). For fatigue rate, only S (18.4% ± 12.0%) was significantly lower than BL (32.9% ± 8.4%). Total testosterone (TT) and growth hormone (GH) were significantly elevated at IP and 15P in all conditions. The GH response was significantly lower, however, in S and P than in BL. The TT and GH responses did not differ between S and P. These results indicated that a supplement consisting of amino acids, creatine, taurine, caffeine, and glucuronolactone can modestly improve high-intensity endurance; however, the anabolic-hormonal response was not augmented. [ABSTRACT FROM AUTHOR]

Although pre-event static stretching (SS) is an accepted practice in most youth programs, pre-event dynamic exercise (DY) is becoming popular. The purpose of this study was to examine the acute effects of pre-event SS, DY, and combined SS and DY (SDY) on vertical jump (VJ), medicine-ball toss (MB), 10-yard sprint (SP), and pro-agility shuttle run (AG) in teenage athletes (15.5 ± 0.9 years). Thirty athletes participated in three testing sessions in random order on three nonconsecutive days. Before testing, participants performed 5 mm of walking/jogging followed by one of the following 10 mm warm-up protocols: a) five static stretches (2 × 30 s), b) nine moderate-to-high-intensity dynamic movements (2 × 10 yards), or c) five static stretches (1 × 30 s) followed by the same nine dynamic movements (1 × 10 yards). Statistical analysis of the data revealed that performance on the VJ, MB, and SP were significantly (p < .05) improved after DY and SDY as compared with SS. There were no significant differences in AG after the 3 warm-up treatments. The results of this study indicate that pre-event dynamic exercise or static stretching followed by dynamic exercise might be more beneficial than pre-event static stretching alone in teenage athletes who perform power activities. [ABSTRACT FROM AUTHOR]

Examines the effects of Vicoprofen and Ibuprofen on anaerobic performance after muscle damage in healthy men. Interventions to mediate the damage associated with muscle activity; Recovery of force production during an active recovery period; Comparison of the addictive effects of the pharmacological agents on maximal concentric knee-extension torque.

Purpose: This study assessed the effect of whole-body vibration (WBV) of varying frequency and amplitude on metabolic responses during WBV treatment and subsequent aerobic exercise.Methods: Eight men and eight women (21.0 ± 1.9 years) underwent one no-WBV (NV) and six WBV at 30 Hz/low amplitude (30L), 30 Hz/high amplitude (30H), 40 Hz/low amplitude (40L), 40 Hz/high amplitude (40H), 50 Hz/low amplitude (50L), and 50 Hz/high amplitude (50H). During each protocol, subjects performed ten sets of ten body weight squats with 1-min rest period between sets on a vibration platform with a load that represented one of the six frequency-amplitude combinations. Each WBV treatment was immediately followed by 20 min of cycle exercise at 65 % VO2peak. Oxygen uptake (VO2) and rates of carbohydrate (COX) and fat oxidation (FOX) were measured during both the WBV session and subsequent exercise.Results: During WBV, VO2 was higher (p < 0.05) in 40H, 50L and 50H than NV and in 50H than 30L, 30H and 40L. COX was higher (p < 0.05) in 40H, 50L, and 50H than NV, whereas FOX remained indifferent across all protocols. During subsequent exercise, VO2 was higher (p < 0.05) in 50L and 50H than NV and in 50H than 30L. No between-protocol differences were seen for COX or FOX.Conclusion: WBV combined with body weight squats can augment VO2 at 40 Hz of high amplitude and 50 Hz of both low and high amplitudes. This metabolic potentiation remains in effect during subsequent aerobic exercise. WBV did not affect fat oxidation across all vibratory loads. [ABSTRACT FROM AUTHOR]

Resistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 resistance-trained men (24.0 ± 3.0 y, 90.0 ± 13.8 kg, 174.9 ± 20.7 cm) completed pre-training (PRE) assessments of muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity in the RF and VL at 30, 50, and 70% of each muscle’s length; fascicle length (FL) was estimated from respective measurements of MT and PA within each muscle and region. Participants then began a high intensity, low volume (4 x 3–5 repetitions, 3min rest) lower-body resistance training program, and repeated all PRE-assessments after 8 weeks (2 d ∙ wk-1) of training (POST). Although three-way (muscle [RF, VL] x region [30, 50, 70%] x time [PRE, POST]) repeated measures analysis of variance did not reveal significant interactions for any assessment of morphology, significant simple (muscle x time) effects were observed for CSA (p = 0.002) and FL (p = 0.016). Specifically, average CSA changes favored the VL (2.96 ± 0.69 cm2, p < 0.001) over the RF (0.59 ± 0.20 cm2, p = 0.011), while significant decreases in average FL were noted for the RF (–1.03 ± 0.30 cm, p = 0.004) but not the VL (–0.05 ± 0.36 cm, p = 0.901). No other significant differences were observed. The findings of this study demonstrate the occurrence of non-homogenous adaptations in RF and VL muscle size and architecture following 8 weeks of high-intensity resistance training in resistance-trained men. However, training does not appear to influence region-specific adaptations in either muscle. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine acute hematological and mood perception responses to supplementation with p-synephrine alone and in combination with caffeine during quiet sitting. Sixteen subjects visited the laboratory on 6 occasions and were given (in randomized double-blind manner) 103-mg p-synephrine (S), 233-mg caffeine + 104-mg p-synephrine, 240-mg caffeine, 337-mg caffeine + 46-mg p-synephrine, 325-mg caffeine, or a placebo (PL). The subjects sat quietly for 3 hr while completing mood state questionnaires every 30 min. Venous blood samples were collected at baseline (pre) and 3 hr (post) to determine immune, lipid, and chemistry panels. Compared with PL, no significant supplement differences were observed during the S trial with the exception of differential time effects seen in hematocrit (decrease in PL, no change in S), triglycerides and very low-density lipoproteins (no changes in PL, significant decreases in S), and iron (no change in PL, significant elevation in S). Supplements containing caffeine showed increased feelings of attention, excitement, energy, and vigor. These data indicate that consumption of 103-mg p-synephrine does not negatively impact acute blood parameters, does not augment the effects of caffeine, or produce stimulant-like perceptual mood effects. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the acute cardiorespiratory and metabolic effects of a sandbag (SB) resistance exercise protocol and compare the responses to time-matched treadmill running protocols. Eight healthy, resistance-trained men (21.1 6 1.0 years; 86.1 6 7.8 kg) completed 4 protocols of equal duration in random sequence: (a) SB, (b) treadmill running at 60% of ...O2 reserve (60...O2R), (c) treadmill running at 80% of ...O2 reserve (80...O2R), and (d) a control protocol. The SB protocol was 16 minutes in duration and consisted of 3 circuits of 8 multiple-joint exercises (with 11-, 20-, or 48-kg SBs) performed for as many repetitions as possible for 20 seconds followed by a 10-second rest interval before beginning the next exercise. Two minutes of rest was allowed between circuits. Breath-by-breath oxygen consumption (...O2) and heart rate (HR) were recorded throughout each protocol and for 30 minutes postexercise (PE) and blood lactate was determined before and immediately after each protocol. Blood lactate was significantly higher after SB compared with 60...O2R and 80...O2R. Mean and peak HR in SB was significantly higher than 60...O2R but not different from 80...O2R. Mean ...O2 and energy expenditure (EE) in SB was significantly lower than 60...O2R and 80...O2R during each protocol but significantly higher after SB compared with 60...O2R and 80...O2R PE. Compared with 60...O2R and 80...O2R, respiratory exchange ratio was significantly higher during SB and through 5 minutes PE, but was significantly lower at 25-30 minutes PE after SB. Sandbag, as performed in this study, provides a superior metabolic stimulus to treadmill running during the PE period; however, the SB results demonstrate inferior EE compared with running at 60...O2R and 80...O2R. [ABSTRACT FROM AUTHOR]

The purpose of this study was to quantify the acute cardiometabolic responses to a novel training rope (TR) protocol in children. Fifteen boys (10.6 ± 1.4 years) were tested for peak oxygen uptake (...O2) on a treadmill and subsequently (2--7 days later) performed a progressive 10-minute protocol of 5 TR exercises (EX): EX1: standing side-to-side waves, EX2: seated alternating waves, EX3: standing alternating waves, EX4: jumping jacks, and EX5: double-arm slams. Participants performed 2 sets of each TR exercise for 30 seconds per set with a 30-second rest interval between sets and exercises. A 12.8-m TR (4.1 kg) was used for all trials, and a metronome was used to standardize cadence. Peak values for ...O2 and HR during the treadmill test were 47.4 ± 8.8 ml⋅kg-1⋅min-1 and 195.1 ± 6.6 b•min-1, respectively. During the TR protocol, mean ...O2 and HR significantly increased (p ≤ 0.05) from set 1 of EX1 (10.3 ± 2.6 ml⋅kg-1⋅min-1and 103.2 ± 11.6 b⋅min-1, respectively) to set 2 of EX5 (30.0 ± 3.9 ml⋅kg-1⋅min-1 and 168.6 ± 11.8 b⋅min-1, respectively). Percentage of peak ...O2 and peak HR values attained during the TR protocol ranged from 21.5 to 64.8% and from 52.9 to 86.4%, respectively. These descriptive data indicate that TR exercise can pose a moderate to vigorous cardiometabolic stimulus in children and with proper supervision and instruction may serve as a worthwhile complement to youth fitness programs. [ABSTRACT FROM AUTHOR]

The purpose was to examine cardiovascular responses to supplementation with p-synephrine alone and in combination with caffeine during quiet sitting. Sixteen subjects were given (in double-blind manner) either 103 mg of p-synephrine (S), 233 mg of caffeine +104 mg of p-synephrine (LC + S), 240 mg of caffeine (LC), 337 mg of caffeine +46 mg of p-synephrine (HC + S), 325 mg of caffeine (HC), or a placebo. The subjects sat quietly for 3 hr while heart rate (HR) and blood pressure were measured. Only HC + S and HC significantly increased mean systolic blood pressure (SBP) during the second hour and tended to increase mean SBP during the third hour. Mean diastolic blood pressure in S was significantly lower than the other trials during the first and second hours, and mean arterial pressure was significantly lower in S compared to the LC, LC + S, HC, and HC + S trials. No differences were observed in HR. Consumption of p-synephrine may acutely reduce diastolic blood pressure and mean arterial pressure and not affect SBP or HR during quiet sitting. The addition of p-synephrine to caffeine did not augment SBP or HR indicating that consumption of up to 104 mg of p-synephrine does not induce cardiovascular stress during quiet sitting. [ABSTRACT FROM AUTHOR]

The history of resistance training research began with anecdotal ideas and a slow growth of research from the late 1890s through the 1970s. The mid-1970s were a nexus point when resistance training studies evolved from just strength assessments to importance in physiological systems, physical health, and physical performance capabilities for individuals interested in physical fitness through to those seeking elite athletic performances. The pursuit of understanding program design and what mediated successful programs continues today as new findings, replication of old concepts, and new visions with the latest technologies fuel both our understanding and interest in this modality. This brief review highlights some of the important scientific contributions to the evolution of our scientific study of resistance training and provides a literature base analysis for greater quantification of the origins and expanse of such investigations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare differences in muscle strength and self-selected resistance training intensities between trained subjects who trained under the supervision of a personal trainer (PT) and those who trained without supervision (WoPT). Twenty-one trained subjects, men (n = 12) and women (n = 9), completed 3 sessions (separated by 48 hours) in the following sequence: first session, self-selected intensity assessment consisting of performance of 3 sets of 10 repetitions for the leg press (LP), bench press (BP), leg extension (LE), and arm curl (AC) exercises with self-selected load; second session, a 1 repetition maximum (1RM) test to determine subjects' maximal strength in the 4 exercises; and third session, a 10RM test to determine the maximum load completed for 10 repetitions for each exercise. Self-selected training loads were significantly higher in PT compared with WoPT for the LP (by 15.6%), BP (by 26.6%), LE (by 12.1%), and AC (by 22.2%) exercises. Self-selected training loads expressed relative to 1RM and 10RM data were significantly higher in PT (49-59.5% of 1RM; 62.7-77.3% of 10RM) than WoPT (41-58.7% of 1RM; 58.7-76.2% of 10RM) with largest difference observed in the lower-body exercises. Ratings of perceived exertion values were significantly higher in PT compared with WoPT. The results of the present study indicated that supervised resistance training with a personal trainer was advantageous in trained subjects although self-selected loading was still considerably lower than 1RM and 10RM percentage values. [ABSTRACT FROM AUTHOR]

The complexity and redundancy of the endocrine pathways during recovery related to anabolic function in the body belie an oversimplistic approach to its study. The purpose of this review is to examine the role of resistance exercise (RE) on the recovery responses of three major anabolic hormones, testosterone, growth hormone(s), and insulin-like growth factor 1. Each hormone has a complexity related to differential pathways of action as well as interactions with binding proteins and receptor interactions. Testosterone is the primary anabolic hormone, and its concentration changes during the recovery period depending on the upregulation or downregulation of the androgen receptor. Multiple tissues beyond skeletal muscle are targeted under hormonal control and play critical roles in metabolism and physiological function. Growth hormone (GH) demonstrates differential increases in recovery with RE based on the type of GH being assayed and workout being used. IGF-1 shows variable increases in recovery with RE and is intimately linked to a host of binding proteins that are essential to its integrative actions and mediating targeting effects. The RE stress is related to recruitment of muscle tissue with the glandular release of hormones as signals to target tissues to support homeostatic mechanisms for metabolism and tissue repair during the recovery process. Anabolic hormones play a crucial role in the body’s response to metabolism, repair, and adaptive capabilities especially in response to anabolic-type RE. Changes of these hormones following RE during recovery in the circulatory biocompartment of blood are reflective of the many mechanisms of action that are in play in the repair and recovery process. [ABSTRACT FROM AUTHOR]

Powerlifters routinely focus on 3 exercises: bench press, squat, and deadlift. This focus may predispose them to the development of muscle imbalances in either the upper or lower extremity which might also influence posture. Therefore, the purpose of the present study was to examine the agonist:antagonist strength ratios and their relationship to postural measures among powerlifters. An ex post facto study design compared 15 male powerlifters (35.3 ± 13.7 years old) and 15 age-matched controls (34.9 ± 14.6 years old). Maximal isometric strength tests were conducted using handheld dynamometry. Posture was evaluated using pectoralis minor length, pelvic tilt, thoracic kyphosis, and lumbar lordosis. Strength imbalances were observed for shoulder horizontal adduction:abduction (2.57 ± 0.58 vs. 1.78 ± 0.28; p < 0.001) and knee flexion:extension (0.61 ± 0.15 vs. 0.50 ± 0.10; p = 0.033). Pectoralis minor length was significantly shorter among the powerlifters (6.1 ± 1.9 vs. 4.2 ± 1.4; p = 0.005); however, there was no statistical difference in thoracic kyphosis (37.7 ± 9.4 vs. 39.1 ± 10.9; p = 0.722), pelvic tilt (10.6 ± 3.6 vs. 11.3 ± 3.7; p = 0.622), or lumbar lordosis (25.0 ± 7.6 vs. 23.0 ± 8.4; p = 0.500) angles. Strength imbalances, including shoulder horizontal adduction:abduction and knee flexion:extension, and a shortened pectoralis minor may evolve as training adaptations among powerlifters, whereas thoracic kyphosis, pelvic tilt, and lumbar lordosis remain unchanged. [ABSTRACT FROM AUTHOR]

Partial least squares regression structural equation modeling (PLS-SEM) was used to examine relationships between the endocrine response to resistance exercise and muscle hypertrophy in resistance-trained men. Pretesting (PRE) measures of muscle size (thickness and cross-sectional area) of the vastus lateralis and rectus femoris were collected in 26 resistance-trained men. Participants were randomly selected to complete a high-volume (VOL, n = 13, 10-12RM, 1-minute rest) or high-intensity (INT, n = 13, 3-5RM, 3-minute rest) resistance training program. Blood samples were collected at baseline, immediately postexercise, 30-minute, and 60-minute postexercise during weeks 1 (week 1) and 8 (week 8) of training. The hormonal responses (testosterone, growth hormone [22 kD], insulin-like growth factor-1, cortisol, and insulin) to each training session were evaluated using area-under-the-curve (AUC) analyses. Relationships between muscle size (PRE), AUC values (week 1 + week 8) for each hormone, and muscle size (POST) were assessed using a consistent PLS-SEM algorithm and tested for statistical significance (p ≤ 0.05) using a 1,000 samples consistent bootstrapping analysis. Group-wise comparisons for each relationship were assessed through independent f-tests. The model explained 73.4% (p < 0.001) of variance in muscle size at POST. Significant pathways between testosterone and muscle size at PRE (p = 0.043) and muscle size at POST (p = 0.032) were observed. The ability to explain muscle size at POST improved when the model was analyzed by group (INT: R² = 0.882; VOL: R² = 0.987; p < 0.001). No group differences in modal quality were found. Exercise-induced testosterone elevations, independent of the training programs used in this study, seem to be related to muscle growth. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects of two different resistance training programs, high intensity (INT) and high volume (VOL), on changes in isometric force (FRC), rate of force development (RFD), and barbell velocity during dynamic strength testing. Methods: Twenty-nine resistance-trained men were randomly assigned to either the INT ( n = 15, 3-5 RM, 3-min rest interval) or VOL ( n = 14, 10-12 RM, 1-min rest interval) training group for 8 weeks. All participants completed a 2-week preparatory phase prior to randomization. Measures of barbell velocity, FRC, and RFD were performed before (PRE) and following (POST) the 8-week training program. Barbell velocity was determined during one-repetition maximum (1RM) testing of the squat (SQ) and bench press (BP) exercises. The isometric mid-thigh pull was used to assess FRC and RFD at specific time bands ranging from 0 to 30, 50, 90, 100, 150, 200, and 250 ms. Results: Analysis of covariance revealed significant ( p < 0.05) group differences in peak FRC, FRC at 30-200 ms, and RFD at 50-90 ms. Significant ( p < 0.05) changes in INT but not VOL in peak FRC (INT: 9.2 ± 13.8 %; VOL: −4.3 ± 10.2 %), FRC at 30-200 ms (INT: 12.5-15.8 %; VOL: −1.0 to −4.3 %), and RFD at 50 ms (INT: 78.0 ± 163 %; VOL: −4.1 ± 49.6 %) were observed. A trend ( p = 0.052) was observed for RFD at 90 ms (INT: 58.5 ± 115 %; VOL: −3.5 ± 40.1 %). No group differences were observed for the observed changes in barbell velocity. Conclusions: Results indicate that INT is more advantageous than VOL for improving FRC and RFD, while changes in barbell velocity during dynamic strength testing are similarly improved by both protocols in resistance-trained men. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to examine the metabolic, lipolytic, and cardiovascular responses to supplementation with p-synephrine alone and in combination with caffeine during resistance exercise (RE).Methods: Twelve healthy men performed a control RE protocol (6 × 10 repetitions of squats) and were randomly assigned (using a double-blind crossover design with random protocol sequencing) to a supplement sequence: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). Subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 minutes, performed the RE protocol, and sat quietly for 30 minutes. Blood samples were collected at rest (T1), after sitting quietly for 45 minutes (T2), immediately following RE (T3), and 15 minutes (T4) and 30 minutes (T5) postexercise. Oxygen consumption (VO2) and heart rate (HR) data were collected throughout.Results: Serum glycerol was significantly elevated at T2 only in S and SCF and T3 to T5 in all treatments. Nonesterified fatty acid (NEFA) concentrations did not differ between treatments. Plasma glucose was significantly elevated compared to T1 with highest area under the curve values seen in SCF. Mean VO2 and energy expenditure (EE) were significantly higher in S and SCF through 30 minutes postexercise. Fat oxidation rates favored S and SCF between 25 and 30 minutes postexercise. Mean HR during RE was significantly highest in SCF.Conclusions: Supplementation with S and SCF increases lipolysis primarily at rest and increases VO2, EE, and fat oxidation rates 30 minutes following RE. No HR changes were observed unless caffeine was added. [ABSTRACT FROM AUTHOR]

Background: Little is known concerning the potential ergogenic effects of p-synephrine supplementation. Therefore, the purpose of the present study was to examine the effects of supplementation with p-synephrine alone and in combination with caffeine on free-weight resistance exercise performance. Methods: Twelve healthy, college-aged men performed a control (CT) resistance exercise protocol consisting of 6 sets of squats for up to 10 repetitions per set using 80 % of their one repetition-maximum (1RM) with 2 min of rest in between sets. Each subject was randomly assigned (in double-blind, balanced manner) to a treatment sequence consisting of use of 3 supplements: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). For each supplement treatment (separated by 1 week), subjects consumed the supplement for 3 days prior to each protocol and the morning of each protocol, and subsequently did not consume any supplements for 3 days following (i.e. wash-out period). On each protocol day, subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 min, performed the resistance exercise protocol, and sat quietly for 30 min post exercise. Performance (repetition number, force, velocity and power), blood lactate, and ratings of perceived exertion (RPE) data were collected during each protocol. Results: Supplements SCF and S produced a significantly (P < 0.05) greater number of repetitions performed than CT (by 11.0 ± 8.0 %) and P (by 6.0 ± 7.0 %) and a 10.6 ± 12.0 % greater increase in volume load per protocol than CT and P. Most of the differences were seen during the last 3 sets. Mean power and velocity for all 6 sets were significantly higher in SCF compared to CT and P by ~6.2 ± 8.0 %. No supplement effects were observed in RPE or blood lactate, and no adverse side effects were observed or reported. Conclusions: S and SCF augmented resistance exercise performance (total repetitions, volume load) without increasing blood lactate or RPE. The addition of caffeine in SCF increased mean power and velocity of squat performance. These results indicate supplementation with S and SCF can enhance local muscle endurance during resistance exercise. [ABSTRACT FROM AUTHOR]

Background: Little is known concerning the potential ergogenic effects of p-synephrine supplementation. Therefore, the purpose of the present study was to examine the effects of supplementation with p-synephrine alone and in combination with caffeine on free-weight resistance exercise performance. Methods: Twelve healthy, college-aged men performed a control (CT) resistance exercise protocol consisting of 6 sets of squats for up to 10 repetitions per set using 80 % of their one repetition-maximum (1RM) with 2 min of rest in between sets. Each subject was randomly assigned (in double-blind, balanced manner) to a treatment sequence consisting of use of 3 supplements: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). For each supplement treatment (separated by 1 week), subjects consumed the supplement for 3 days prior to each protocol and the morning of each protocol, and subsequently did not consume any supplements for 3 days following (i.e. wash-out period). On each protocol day, subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 min, performed the resistance exercise protocol, and sat quietly for 30 min post exercise. Performance (repetition number, force, velocity and power), blood lactate, and ratings of perceived exertion (RPE) data were collected during each protocol. Results: Supplements SCF and S produced a significantly (P < 0.05) greater number of repetitions performed than CT (by 11.0 ± 8.0 %) and P (by 6.0 ± 7.0 %) and a 10.6 ± 12.0 % greater increase in volume load per protocol than CT and P. Most of the differences were seen during the last 3 sets. Mean power and velocity for all 6 sets were significantly higher in SCF compared to CT and P by ~6.2 ± 8.0 %. No supplement effects were observed in RPE or blood lactate, and no adverse side effects were observed or reported. Conclusions: S and SCF augmented resistance exercise performance (total repetitions, volume load) without increasing blood lactate or RPE. The addition of caffeine in SCF increased mean power and velocity of squat performance. These results indicate supplementation with S and SCF can enhance local muscle endurance during resistance exercise. [ABSTRACT FROM AUTHOR]

This article describes the use of two different rest intervals to quantify and compare the acute metabolic responses to battling rope (BR) exercise in athletes. In one group, subjects did not exercise for at least 24 hours before each testing session. Second control protocol involved a quiet sitting period 30 minutes in duration to offer baseline (BL) non-exercise metabolic data.

This investigation compared the effect of high-volume ( VOL) versus high-intensity ( INT) resistance training on stimulating changes in muscle size and strength in resistance-trained men. Following a 2-week preparatory phase, participants were randomly assigned to either a high-volume ( VOL; n = 14, 4 × 10-12 repetitions with ~70% of one repetition maximum [1 RM], 1-min rest intervals) or a high-intensity ( INT; n = 15, 4 × 3-5 repetitions with ~90% of 1 RM, 3-min rest intervals) training group for 8 weeks. Pre- and posttraining assessments included lean tissue mass via dual energy x-ray absorptiometry, muscle cross-sectional area and thickness of the vastus lateralis ( VL), rectus femoris ( RF), pectoralis major, and triceps brachii muscles via ultrasound images, and 1 RM strength in the back squat and bench press ( BP) exercises. Blood samples were collected at baseline, immediately post, 30 min post, and 60 min postexercise at week 3 ( WK3) and week 10 ( WK10) to assess the serum testosterone, growth hormone ( GH), insulin-like growth factor-1 ( IGF1), cortisol, and insulin concentrations. Compared to VOL, greater improvements ( P < 0.05) in lean arm mass (5.2 ± 2.9% vs. 2.2 ± 5.6%) and 1 RM BP (14.8 ± 9.7% vs. 6.9 ± 9.0%) were observed for INT. Compared to INT, area under the curve analysis revealed greater ( P < 0.05) GH and cortisol responses for VOL at WK3 and cortisol only at WK10. Compared to WK3, the GH and cortisol responses were attenuated ( P < 0.05) for VOL at WK10, while the IGF1 response was reduced ( P < 0.05) for INT. It appears that high-intensity resistance training stimulates greater improvements in some measures of strength and hypertrophy in resistance-trained men during a short-term training period. [ABSTRACT FROM AUTHOR]

The article presents a study that evaluates the effects of the training muscle groups through the use of split-body routine (SPLIT) 1 day per week and total-body routine 3 days per week on muscular adaptation among well-trained men. The study was conducted through pairing the participants according to baseline strength and then randomly assigning them to 1 of the two groups. The results of the study reveal several factors that can affect the physical routines of the participants.

The article focuses on a study conducted to determine the benefits of resistance training modalities involving whole-body vibration (WBV). It discusses the comparative effect of dynamic and static squats during WBV on the increased quadricep force produced due to dynamic extension of isokinetic knee and flexion exercise. The methods involved were prestrength and poststrength testing of individuals ranging from 18-25 years.

The article discusses the importance, effects and benefits of physical education for the children during primary school. Topics discussed include fundamental integrative training (FIT) method to enhance children's health and performance skills, statistical analysis of the data collected for investigation and the practical applications to enhance skill performance and muscular strength.

The article discusses research comparing the acute metabolic responses to traditional resistance, body-weight, and battling rope (BR) exercises in 10 resistance-trained men. Topics include the participants' exercise protocol, which included repetitions of push-ups (PUs), PUs on a BOSU ball, and PUs with lateral crawls, measurements of mean oxygen consumption during PU-based and plank exercises, and acute energy expenditure (EE) in body fat reduction.

The article reports on research which was conducted to investigate muscular adaptations to a volume-equated bodybuilding-type training program vs. a powerlifting-type routine in well-trained subjects. Researchers evaluated 17 young men. They found that both bodybuilding and powerlifting-type training promoted similar increases in muscular size, but concluded that powerlifting-type training is superior for enhancing maximal strength.

The article discusses research investigating the effect of intensity fluctuation on oxygen uptake and substrate utilization during exercise and recovery in 15 men and women. Topics include the popularity of intensity fluctuation exercise routines, such as spinning and treading, in the fitness industry, the physiological impact of intensity fluctuation, such as glucose tolerance, and the acute metabolic effects of spinning versus a steady-state exercise of the same overall intensity.

The article presents a study on the relationship between maximal oxygen consumption (Vo2max) and acute resistance exercise performance, as well as the maximal aerobic capacity and acute metabolic effects of exercise sequencing, with a focus on rest interval (RI) lengths. Resistance training, athletic performance, and strength testing are also discussed.

Context: Integrative neuromuscular training (INT) has successfully enhanced physical fitness and reduced abnormal biomechanics, which appear to decrease injury rates in adolescent female athletes. If not addressed at the proper time, low levels of physical fitness and abnormal mechanics may predispose female athletes to an increased risk of musculoskeletal injuries. Objectives: To evaluate sex-specific effects of INT on selected measures of health- and skill-related fitness in children during physical education (PE). Design: Cohort study. Setting: Public primary school. Patients or Other Participants: Forty children (16 boys, 24 girls; age = 7.6 ± 0.3 years, height = 124.5 ± 6.4 cm, mass = 29.5 ± 7.6 kg) from 2 second-grade PE classes. Intervention(s): The classes were randomized into the PE-plus-INT group (10 boys, 11 girls) or the control group (6 boys, 13 girls) that participated in traditional PE. The INT was performed 2 times per week during the first approximately 15 minutes of each PE class and consisted of body weight exercises. Main Outcome Measure(s): Push-up, curl-up, standing long jump, single-legged hop, single-legged balance, sit-and-reach flexibility test, shuttle run, and 0.8-km run. Results: At baseline, the boys demonstrated higher levels of performance in most of the fitness measurements as evidenced by greater performance on the push-up, standing long jump, single-legged hop, shuttle run, and 0.8-km run (P < .05). In the evaluation of the training effects, we found intervention effects in the girls for enhanced INT-induced gains in performance relative to the control group on the curl-up, long jump, single-legged hop, and 0.8-km run (P < .05) after controlling for baseline. Boys did not demonstrate similar adaptations from the INT program (P ≥ .05). Conclusions: These data indicate that INT is an effective and time-efficient addition to PE for enhancing motor skills and promoting physical activity in children. Seven-year-old girls appeared to be more sensitive to the effects of INT than 7-year-old boys. Future research is warranted to confirm these effects in larger cohorts of children. [ABSTRACT FROM AUTHOR]

The article discusses a study which concerned the jumping performance of college athletes, focusing on the impact of postactivation potentiation protocols with and without whole body vibration. Topics include countermovement jumps, drop jumps, complex training, and decreases in performance that may have resulted from the use of a whole body vibration platform.

To examine metabolic interaction between meal and exercise, 10 men and 10 women completed three trials: (1) exercise (E), (2) consumption of a meal (M), and (3) consumption of a meal followed by exercise (M+E). All trials commenced after an overnight fast and were preceded by a rest period in which resting metabolic rate (RMR) was determined. The meal contained 721 kilocalories composed of 41%, 36%, and 23% of carbohydrate, lipids, and protein, respectively. Exercise protocol consisted of three continuous 10-minute cycling at 50%, 60%, and 70% VO2peak. Measurement began 60 min after the start of the meal and included VO2 that was used to determine meal-induced thermogenesis (MIT). VO2 was greater (p <.05) in M+E than in E at 50% and 60% VO2peak. MIT was higher (p <.05) during exercise at 50% VO2peak than at rest. It appears that postprandial exercise of mild intensities can potentiate MIT, thereby provoking a greater increase in energy expenditure. [ABSTRACT FROM AUTHOR]

The article discusses a study which was aimed to compare the effects of three different volume of resistance training (RT) on maximum strength and average power in college team sport athletes with no previous RT experience. The study included 32 subjects, 20 men and 12 women, who were randomly divided into 4 groups. The study concluded that a low volume RT could be an option for maintaining strength and enhancing lower-body AP in team sport athletes.

Few data exist examining the body composition, endocrine, and anaerobic exercise performance changes over a competitive wrestling season. Eighteen NCAA wrestlers were tested for endocrine markers, body composition, hydration, grip strength, and power on four occasions: prior to pre-season training (T1); after pre-season training 3 days prior to the first seasonal meet (T2); mid-season one day prior to a meet (T3); and at the end of the season 2-3 days following the last meet (T4). Body mass, percent body fat (BF %), and fat mass were significantly lower ( P ≤ 0.05) at T2 and T3 compared to T1 but were not different between T1 and T4. Lean body mass was significantly reduced at T2 only. Urine specific gravity was significantly elevated at T3 compared to T1, T2, and T4. Resting cortisol concentrations did not change but resting testosterone concentrations were significantly reduced at T2, T3, and T4. Maximal grip strength was significantly reduced at T2. Vertical jump peak power was significantly reduced at T2, T3, and T4. Wingate peak power was significantly reduced at T2 and T3. However, Wingate average power and total work did not significantly change. Fatigue rate during the Wingate test was significantly improved at T2, T3, and T4 compared to T1. In conclusion, body mass, BF %, and measures of peak force and power were reduced for most of the competitive wrestling season. Competitive wrestling reduces resting total testosterone concentrations throughout the entire season. [ABSTRACT FROM AUTHOR]

The article discusses research which was conducted to investigate changes in creatine kinase (CK) and cortisol in national Collegiate Athletic Association division I American football players during a playing season. Researchers evaluated 22 players. They found that no significant changes in CK concentrations were observed over the season and that no changes in serum cortisol concentrations were observed.