Resistance Exercise Session Research Articles

Ingestion of a Multi-Ingredient Supplement Does Not Alter Exercise-Induced Satellite Cell Responses in Older Men

Nutritional supplementation can have beneficial effects on body composition, strength, and function in older adults. However, whether the response of satellite cells can be altered by nutritional supplementation in older adults remains unknown. We assessed whether a multi-ingredient protein-based supplement taken over a prolonged period of time could alter the muscle satellite cell response after exercise in older men. Twenty-seven older men [mean ± SD age: 73±1 y; mean ± SD body mass index (kg/m2): 28±1] participated in a randomized double-blind experiment. Participants were randomly divided into an experimental (EXP) group (n=13) who consumed a multi-ingredient protein-based supplement [30 g whey protein, 2.5 g creatine, 500 IU vitamin D, 400 mg Ca, and 1500 mg n-3 (ω-3) polyunsaturated fatty acids] 2 times/d for 7 wk or a control (CON; 22 g maltodextrin) group (n=14). After 7 wk of supplementation, all participants performed a single resistance exercise session, and muscle biopsy samples were taken from the vastus lateralis before and 24 and 48 h after exercise. Immunohistochemistry was used to assess the change in type I and II muscle fiber satellite cell content and activation status of the cells. In addition, mRNA expression of the myogenic regulatory factors was determined by using reverse transcriptase-polymerase chain reaction. In response to the single bout of exercise, type I muscle fiber satellite cell content was significantly increased at 24 h (0.132±0.015 and 0.131±0.011 satellite cells/fiber in CON and EXP groups, respectively) and 48 h (0.126±0.010 and 0.120±0.012 satellite cells/fiber in CON and EXP groups, respectively) compared with pre-exercise (0.092±0.007 and 0.118±0.017 satellite cells/fiber in CON and EXP groups, respectively) muscle biopsy samples (P<0.01), with no difference between the 2 groups. In both groups, we observed no significant changes in type II muscle fiber satellite cell content after exercise. Ingesting a multi-ingredient protein-based supplement for 7 wk did not alter the type I or II muscle fiber satellite cell response during postexercise recovery in older men. This trial was registered at www.clinicaltrials.gov as NCT02281331.

Effect of Rest Interval Length Between Sets on Total Load Lifted and Blood Lactate Response During Total-Body Resistance Exercise Session

Objectives: This study aimed to investigate the effect of different rest interval durations between sets during full-body resistance exercise sessions on total load lifted and blood lactate concentrations in resistance-trained individuals. Methods: Ten healthy young men (age: 23 ± 6.5 years; total body mass: 82.8 ± 10.6 kg, height: 177.3 ± 0.1 cm) randomly performed 3 resistance exercise sessions with different rest intervals between sets (30 seconds, 60 seconds and 120 seconds). The resistance exercise sessions consisted of 6 full-body exercises (bench press; seated low row; shoulder press; back squat; leg press 45° and seated calf raise) performed with 4 sets of 10 repetitions maximum (RM). Total load lifted (sets × repetitions × load (Kgf)) and lactate blood concentration were determined for each exercise session. One way, repeated measures analysis of variance (ANOVA) followed by Bonferroni’s post-hoc test were used for multiple comparisons. Results: The total load lifted was significantly (P < 0.001) lower for 30 seconds (26382.0 ± 4100.3 kg) rest interval compared with 60 seconds (28864.5 ± 4139.7 kg) and 120 seconds (30064.4 ± 3966.4 kg). The blood lactate response was not different among the 3 rest interval conditions investigated, with mean peak values of 7.05 ± 1.69, 7.26 ± 2.77 and 6.90 ± 3.79 mM for 30 seconds, 60 seconds and 120 seconds, respectively. Conclusions: In conclusion, rest interval durations of 60 seconds and 120 seconds between sets favored a higher total load lifted in the exercise session when compared to the 30 seconds rest interval. The rest protocols implemented in the present study promoted a similar metabolic response (e.g. blood lactate concentration) to a full-body resistance exercise session in trained subjects.

Clinical Oncology Society of Australia position statement on exercise in cancer care.

Clinical research has established exercise as a safe and effective intervention to counteract the adverse physical and psychological effects of cancer and its treatment. This article summarises the position of the Clinical Oncology Society of Australia (COSA) on the role of exercise in cancer care, taking into account the strengths and limitations of the evidence base. It provides guidance for all health professionals involved in the care of people with cancer about integrating exercise into routine cancer care. Main recommendations: COSA calls for: exercise to be embedded as part of standard practice in cancer care and to be viewed as an adjunct therapy that helps counteract the adverse effects of cancer and its treatment; all members of the multidisciplinary cancer team to promote physical activity and recommend that people with cancer adhere to exercise guidelines; and best practice cancer care to include referral to an accredited exercise physiologist or physiotherapist with experience in cancer care. Changes in management as a result of the guideline: COSA encourages all health professionals involved in the care of people with cancer to: discuss the role of exercise in cancer recovery; recommend their patients adhere to exercise guidelines (avoid inactivity and progress towards at least 150 minutes of moderate intensity aerobic exercise and two to three moderate intensity resistance exercise sessions each week); and refer their patients to a health professional who specialises in the prescription and delivery of exercise (ie, accredited exercise physiologist or physiotherapist with experience in cancer care).

Effects of carbohydrate and branched-chain amino acid beverage ingestion during acute upper body resistance exercise on performance and postexercise hormone response.

The purpose of this investigation was to examine the individual and combined effects of ingesting carbohydrates (CHO) and branched-chain amino acids (BCAA) during high-volume upper body resistance exercise (RE) on markers of catabolism and performance. Thirteen resistance-trained males completed 4 experimental trials with supplementation, ingesting beverages containing CHO, BCAA, CHO+BCAA, or placebo (PLA) in a randomized, double-blind design. The beverages were ingested in 118-mL servings 6 times during an ∼60-min RE session consisting of bench press, bent-over row, incline press, and close-grip row. Each RE was performed with 5 sets of repetitions at 65% 1-repetition maximum until volitional fatigue. Blood samples were collected at baseline, immediately postexercise, and 60 min postexercise to assess glucose and insulin. Cortisol was assessed immediately and at 60 min postexercise. No significant performance benefits were observed for any RE. CHO+BCAA (152.4 ± 71.4 ng/mL) resulted in the lowest cortisol levels, which was lower than BCAA and PLA (193.7 ± 88.5, 182.8 ± 67.5 ng/mL, p < 0.05), but not different from CHO (165 ± 76.5 ng/mL, p = 0.342). Postexercise insulin concentrations were significantly higher with CHO (4.79 ± 3.4 mU/L) compared with BCAA and PLA (3.7 ± 2.0, 3.5 ± 1.8 mU/L, p < 0.05), but not different from CHO+BCAA (4.3 ± 2.5 mU/L, p = 0.339). There was no treatment effect for glucose, but glucose significantly increased from baseline to immediately postexercise and significantly decreased at 60 min postexercise. Ingesting beverages containing CHO with or without BCAA during upper body resistance exercise may promote a more favorable postexercise less catabolic environment.

Environmental hypoxia favors myoblast differentiation and fast phenotype but blunts activation of protein synthesis after resistance exercise in human skeletal muscle.

We hypothesized that a single session of resistance exercise performed in moderate hypoxic (FiO2: 14%) environmental conditions would potentiate the anabolic response during the recovery period spent in normoxia. Twenty subjects performed a 1-leg knee extension session in normoxic or hypoxic conditions. Muscle biopsies were taken 15 min and 4 h after exercise in the vastus lateralis of the exercised and the nonexercised legs. Blood and saliva samples were taken at regular intervals before, during, and after the exercise session. The muscle fractional-protein synthetic rate was determined by deuterium incorporation into proteins, and the protein-degradation rate was determined by methylhistidine release from skeletal muscle. We found that: 1) hypoxia blunted the activation of protein synthesis after resistance exercise; 2) hypoxia down-regulated the transcriptional program of autophagy; 3) hypoxia regulated the expression of genes involved in glucose metabolism at rest and the genes involved in myoblast differentiation and fusion and in muscle contraction machinery after exercise; and 4) the hypoxia-inducible factor-1α pathway was not activated at the time points studied. Contrary to our hypothesis, environmental hypoxia did not potentiate the short-term anabolic response after resistance exercise, but it initiated transcriptional regulations that could potentially translate into satellite cell incorporation and higher force production in the long term.-Gnimassou, O., Fernández-Verdejo, R., Brook, M., Naslain, D., Balan, E., Sayda, M., Cegielski, J., Nielens, H., Decottignies, A., Demoulin, J.-B., Smith, K., Atherton, P. J., Fancaux, M., Deldicque, L. Environmental hypoxia favors myoblast differentiation and fast phenotype but blunts activation of protein synthesis after resistance exercise in human skeletal muscle.

Acute metabolic responses following different resistance exercise protocols

Resistance exercise (RE) can be an excellent modality for glycemic control. Studies have demonstrated that a single RE session can reduce glycemia in subjects with or without diabetes. Little is known about the dose-response effect of RE on glycemic control. This study aimed to investigate the acute metabolic responses after different RE protocols. Eighty-nine males were separated into six groups that completed RE protocols: 2 sets of 18 repetitions (2 × 18 at 50% of 1-repetition maximum (1RM); n = 19); 3 sets of 12 repetitions (3 × 12 at 70% of 1RM; n = 14); 4 sets of 9 repetitions (4 × 9 at 80% of 1RM; n = 13); 6 sets of 6 repetitions (6 × 6 at 90% of 1RM; n = 19); circuit (2 × 18 at 50% of 1RM; n = 12); and a control session (n = 12). The exercise sequence consisted of 8 exercises. An oral glucose tolerance test was conducted with metabolic measurements immediately after each RE protocol and every 15 min until 120 min of recovery. All groups exhibited significantly lower values (p < 0.05) in the glucose area under the curve (AUC) when compared with control over a 120 min monitoring period. The 6 × 6 group showed a significantly lower glucose AUC versus the 3 × 12 and 4 × 9 groups (p = 0.004; p = 0.001, respectively). As for blood lactate, the control and 6 × 6 groups exhibited lower AUC values versus all other groups (p < 0.05), and AUC for glucose and lactate concentration showed a negative and significant correlation (r = -0.46; p < 0.0001). It appears that a combination of 9-12 repetitions per set and 3-4 sets per muscle group might be optimal for acute postprandial glucose control.

L-Arginine supplementation does not improve muscle function during recovery from resistance exercise

The purpose of this study was to investigate the effects of l-arginine supplementation on muscle recovery after a single session of high-intensity resistance exercise (RE). Twenty healthy young adult participants (22.8 ± 3.4 years old) were assigned to 1 of 2 groups (N = 10 per group): a placebo-supplement group or an l-arginine-supplement group. The groups completed a session of high-intensity RE (0 h) and 3 subsequent fatigue test sessions (at 24, 48, and 72 h postexercise) to assess the time course of muscle recovery. During the test sessions, we assessed the following dependent variables: number of maximum repetitions, electromyographic signal (i.e., root mean square (RMS) and median frequency (MF) slope), muscle soreness, perceived exertion, blood levels of creatine kinase (CK) and lactate, and testosterone:cortisol ratio. Number of maximum repetitions increased at 48 and 72 h postexercise in both groups (time, P < 0.05). CK levels and muscle soreness increased at 24 h postexercise and then progressively returned to baseline at 72 h post exercise in both groups (time, P < 0.05). Lactate levels increased immediately postexercise but were reduced at 24 h postexercise in both groups (time, P < 0.05). Testosterone:cortisol ratio, RMS, and MF slope remained unchanged during the recovery period in both groups (time, P > 0.05). No significant (P > 0.05) group × time interaction was found for all dependent variables during the recovery period. In conclusion, our data indicate that l-arginine supplementation does not improve muscle recovery following a high-intensity RE session in young adults.

Response of creatine kinase and lactate dehydrogenase enzymes to rest interval between sets and set-repetition configuration during bouts of eccentric exercise.

Background and aimsVarious studies have demonstrated that different rest intervals and set-repetition have a significant effect on hormonal and metabolic responses. These factors can lead to different muscle damage responses.MethodsForty untrained subjects (25.4 ± 0.068 years, height: 1.74 ± 0.97 cm, and weight: 30.8 ± 8.48 kg) in three sessions of eccentric resistance exercise with 24-h rest between each session participated in this study. Subjects were divided into four groups of 10 subjects who performed 50 eccentric contractions with different number of 5 and 10 sets, 5 and 10 repetitions, and the interset rest interval 1 and 3 min with 85% of one repetition maximum (1RM). Creatine kinase and lactate dehydrogenase were measured immediately before each session, immediately after each session, and 24 h after the last training session. Variance analysis with repeated measurement and Bonferroni post hoc test were used for statistical analysis of data.ResultsThere is no significant difference in creatine kinase and lactate dehydrogenase between four groups at different time points (p < 0.05).ConclusionThe repetition of eccentric exercise for three consecutive days causes muscle damage that is independent of manipulating the interset rest intervals and the number of set-repetition.

Acute effects of blood flow restriction on exercise-induced free radical production in young and healthy subjects

The main purpose of this study was to investigate the acute local and systemic effects of low-load resistance exercise (30% 1RM) with partial vascular occlusion on exercise-induced free radical production and to compare these effects with other established training methods.Fifteen young and healthy males (25 ± 3 years) performed the following four sessions in a counterbalanced order on separate days: low-load resistance exercise (LI: 30% 1RM), low-load resistance exercise with blood flow restriction (LIBR: 30% 1RM), high-load resistance exercise (HI: 80% 1RM) and an additional session without exercise but blood flow restriction only (BR). Blood samples were obtained 15 min prior to and immediately after exercise sessions from the right index finger and first toe. To analyze concentrations of reactive oxygen species (ROS), electron paramagnetic resonance (EPR) spectroscopy was used. Additionally, mitochondrial ROS production was measured by adding inhibitors of electron transport chain complex III. There was an increased systemic ROS generation after the LIBR session from 0.837 ± 0.093 to 0.911 ± 0.099 µmol/l/min. However, no local or systemic time × condition interaction was detected for ROS production. Regarding mitochondrial ROS production, results were not different between the conditions. Although the low-load resistance exercise session with partial vascular occlusion elicited systemic increases of ROS production, no significant changes were seen on a local level. We assume that this ROS concentration might not be high enough to induce cellular damage but is rather involved in muscle remodulation. However, this needs to be confirmed by future research.

Comparison of the effect of rest interval between sets and set – repetition configuration during bouts of eccentric exercise on muscle damage and inflammatory markers

Background and Objective: Various studies have demonstrated that different rest Intervals has a significant effect on hormonal, metabolic and cardiovascular responses. This factors can lead to different muscle damage responses. Materials and Methods: 40 untrained subjects (25.4 ± 0.068 years, height 1.74 ± 0.97 cm and weight 30.8 ± 8.48 kg) in three sessions of eccentric resistance exercise with 24 hours rest between each session Participated in this study. Subjects were divided into 4 groups, A group: 5 sets of 10 repetition with the interset rest interval 1 minutes, B group: 10 sets of 5 repetition with the interset rest interval 3 minutes, C group: 10 sets of 5 repetition with the interset rest interval 3 minutes and D group: 5 sets of 10 repetition with the interset rest interval 3 minutes that performed 50 eccentric contractions with 85% of one repetition maximum. Each set includes 10 or 5 contractions that lower a person’ s weight in 3 s and at least 2 s to reach the next contraction without weights placed in full flexion Around 1- or 3-min rest was given between each set. The experimental protocol was repeated for three consecutive days. The range of motion, the arm circumference, soreness and Alpha necrosis tumor factor were measured immediately before , immediately after and 24 hours after training. Results: Variance analysis with repeated measure demonstrated, non-dominant arm circumference(P= 0.44), soreness (P= 0.76) and alpha necrosis tumor factor (P= 0.37) in different time points in 4 groups significantly increased and the range of motion (P= 0.44) decreased, but no significant difference in all dependent variables were found in 4 groups at different time points (P &lt;0.05). Conclusion: Mechanisms of muscular damage caused by consecutive eccentric activities is independent of manipulating resistance exercise components (rest and the number of set-repetition) and possibly related to the muscular pressure entering to the muscles.

The effect of changes in concentric-eccentric contraction time ratio on hormonal response to resistance exercise in trained men

The aim of this study was to investigate the effect of changing concentric-eccentric contraction time ratio in a single session of resistance exercise on hormonal response in trained men. In a double-blind cross section study design, ten young men (mean age: 26.3 ± 1.2 years, mean weight: 81.2 ± 4.25 kg, and mean height: 178 ± 6 cm) were selected and completed 4 resistance exercise sessions with 3 days’ between sessions interval. Protocols included, 1 second concentric and 1 second eccentric contraction; 3 second concentric and 3 second eccentric contraction; 4 second concentric and 2 seconds eccentric contraction; 2 seconds concentric and 4 seconds eccentric contraction. In each session subjects performed one of the four protocols. The exercise protocol was consisted of leg extension, bench press, hamstring curls and lat pull-down with three sets of eight repetitions and intensity of 0.65 of one repetition maximum. Rest times for sets and exercises were 1 and 2 minutes respectively. Blood samples were collected before and immediately after exercise. Increases in lactate were observed after all protocols. Serum levels of testosterone and growth hormone increased significantly in all, but 1 second concentric and 1 second eccentric contraction protocol, while level of serum cortisol did not change significantly in none of the protocols. The result of this study showed that in a single session of RE, changes in concentric-eccentric contraction time ratio had no effect on hormonal response, however slower contractions produced greater hormonal response compare to normal protocol. Le but de cette étude était d’étudier l’effet, sur la réponse hormonale d’hommes entraînés, du changement temps de contraction concentrique-excentrique. Dix jeunes hommes (âge moyen : 26,3 ± 1,2 années, poids moyen : 81,2 ± 4,25 kg, hauteur moyenne : 178 ± 6 cm) ont été sélectionnés et ont effectué quatre séances d’exercice en résistance à raison de 3 jours d’intervalle entre les sessions. Le protocole prévoyait 1 seconde en concentrique et 1 seconde contraction excentrique, trois secondes en concentrique et trois secondes contraction excentrique, quatre secondes en concentrique et deux secondes de contraction excentrique, deux secondes en concentrique et quatre secondes de contraction excentrique. Dans chaque session, les sujets ont effectué un des quatre protocoles. Le protocole d’exercice consistait en extension de la jambe, développé-couché, hamstring curls et lat pull-down à raison de trois séries de huit répétitions et d’intensité de 0,65 d’une répétition maximale. Les temps de repos pour les jeux et les exercices étaient 1 et 2 minutes respectivement. Des échantillons de sang ont été prélevés avant et immédiatement après l’exercice. Les augmentations de lactate ont été observées après tous les protocoles. Les niveaux de testostérone et d’hormone de croissance sérique ont augmenté de manière significative dans tous les cas, tandis que le niveau de cortisol sérique n’a pas changé de manière significative dans aucun des protocoles. Le résultat de cette étude a montré que dans une seule session d’exercice en résistance, le changement du temps de contraction de concentrique à excentrique n’a aucun effet sur la nature de la réponse hormonale. Cependant contractions plus lentes entraînent une réponse hormonale plus élevée que celle avec le protocole normal.

The effect of CYP1A2 genotype on the ergogenic properties of caffeine during resistance exercise: a randomized, double-blind, placebo-controlled, crossover study

The purpose of this study was to examine the effect of CYP1A2 -163C>A polymorphism on the ergogenic effects of caffeine supplementation during a resistance exercise (RE) session. In a randomized, double-blind, placebo (PL)-controlled, crossover study, 30 resistance-trained men took part in two RE sessions (three sets to failure at 85% of one repetition maximum, 2-min rest between sets), including bench press (BP), leg press (LP), seated cable row, and shoulder press (SP) following caffeine (CAF) (6mgkg-1) or PL (6mgkg-1 of maltodextrin) ingestion 1h prior to the trial. The number of repetitions was recorded after each set, along with calculation of total number of repetitions for each exercise. Genomic DNA was isolated from the whole blood samples for analyzing the CYP1A2 -163C>A polymorphism through amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Subjects were classified as either AA (n = 14) or AC/CC genotypes (n = 16). The two-way ANOVA with repeated measures revealed differences between AAs and AC/CCs under CAF conditions for repetitions performed in sets 1, 2, and 3 of BP (F(1, 28) = 14.84, P = 0.001, ƞ2 = 0.34), LP (F(1, 28) = 8.92, P = 0.006, ƞ2 = 0.24), SR (F(1, 28) = 17.38, P = 0.0001, ƞ2 = 0.38), and SP (F(1, 28) = 3.76, P = 0.063, ƞ2 = 0.11). CAF also increased the total number of repetitions performed for all three sets in AAs versus AC/CCs for BP (F(1, 28) = 8.72, P = 0.006, ƞ2 = 0.23), LP (F(1, 28) = 4.67, P = 0.03, ƞ2 = 0.14), SR (F(1, 28) = 5.54, P = 0.02, ƞ2 = 0.16), and SP (F(1, 28) = 3.89, P = 0.058, ƞ2 = 0.12) in athletes who were homozygous carriers of the A allele, compared to the C allele carriers. Therefore, AA homozygotes were able to carry out a greater total volume of RE work under CAF but not PL conditions, compared to the C allele carriers. In conclusion, acute ingestion of CAF significantly enhanced RE performance in resistance-trained men who were homozygous for the A allele, but not for C allele carriers. Further studies are needed to replicate the potential role of the CYP1A2 -163C>A polymorphism on the ergogenic effects of CAF in other modes of exercise and in other populations.

The effect of lower limb occlusion on recovery following sprint exercise in academy rugby players

ObjectivesThe effects of vascular occlusion on recovery of physiological and neuromuscular markers over 24h, and hormonal reactivity to subsequent exercise were investigated. DesignCounterbalanced, randomised, crossover. MethodsAcademy rugby players (n=24) completed six 50-m sprints (5-min inter-set recovery) before occlusion cuff application (thighs) and intermittent inflation to 171–266mmHg (Recovery) or 15mmHg (Con) for 12-min (two sets, 3-min repetitions, 3-min non-occluded reperfusion). Countermovement jumps, blood (lactate, creatine kinase), saliva (testosterone, cortisol), and perceptual (soreness, recovery) responses were measured before (baseline) and after (post, +2h, +24h) sprinting. Saliva was sampled after a 30-min resistance exercise session performed 24h after sprinting. ResultsAlthough sprinting (total: 40.0±2.8s, p=0.238; average: 6.7±0.5s, p=0.674) influenced creatine kinase (p<0.001, +457.1±327.3μL−1, at 24h), lactate (p<0.001, 6.8±2.3mmolL−1, post), testosterone (p<0.001, −55.9±63.2pgmL−1, at 2h) and cortisol (p<0.001, −0.3±0.3μgdL−1, at 2h) concentrations, countermovement jump power output (p<0.001, −409.6±310.1W; −5.4±3.4cm, post), perceived recovery (p<0.001, −3.0±2.3, post), and muscle soreness (p<0.001; 1.5±1.1, at 24h), vascular occlusion had no effect (all p>0.05) on recovery. In response to subsequent exercise performed 24h after vascular occlusion, testosterone increased pre-to-post-exercise (Recovery: p=0.031, 21.6±44.9pgmL−1; Con: p=0.178, 10.6±36.6pgmL−1) however Δtestosterone was not significantly different (p=0.109) between conditions. ConclusionsVascular occlusion had no effect on physiological or neuromuscular markers 2h or 24h after sprinting or in response to a physical stress test.

EFFECTS OF DIFFERENT VOLUMES OF RESISTANCE EXERCISE ON THE FOOD INTAKE OF RATS

ABSTRACT Introduction: Physical exercise changes food intake after an acute session; however further research is needed to identify the effects of resistance exercise (RE) with different training volumes. Objective: To investigate the effects of acute RE (two sessions) with different training volumes on the food intake of rats. Methods: Twenty four Wistar rats were randomly divided into three groups: control group (who did not perform RE; n=8); RE (stair climbing) with four series (G4, n=8) and overload of 50%, 75%, 90%, and 100% of the maximum load capacity of the animal and RE with eight series (G8; n=8) with two increases of each overload of 50%, 75%, 90%, and 100% of the maximum load capacity of the animal. The average amount of ingested feed was measured for each experimental group 24 and 48 hours after the first RE session and 72 hours after the second RE session. Results: The food intake of the groups that performed the RE session was significantly lower (p&lt;0.05) when compared to the control group only at 24 hours after the first training session. After the second training session (72 h), the G8 showed a significantly lower food intake (p&lt;0.05) when compared to G4 and the control group. However, the food consumption relative to the body mass of the animals (g/gBM) was significantly lower only after the second training session (72 h) in G8 (p&lt;0.05) compared to G4 and the control group. Conclusion: Therefore, the resistance exercise decreases the food intake of rats after an acute session; in addition, a higher training volume seems to be more advantageous. Level of Evidence II; Therapeutic studies - Investigation of treatment results.

Delayed Effects of a Low-Volume, Power-Type Resistance Exercise Session on Explosive Performance.

Tsoukos, A, Veligekas, P, Brown, LE, Terzis, G, and Bogdanis, GC. Delayed effects of a low-volume, power-type resistance exercise session on explosive performance. J Strength Cond Res 32(3): 643-650, 2018-This study examined the delayed effects of a power-type training session on explosive performance. Seventeen well-trained male power and team sport athletes (age: 22.7 ± 5.5 years, height: 181 ± 8 cm, body mass: 80.7 ± 8.6 kg, body fat: 9.2 ± 1.7%, 1 repetition maximum (1RM) half-squat: 163 ± 29 kg) performed 4 sessions (2 experimental and 2 control) 1 week apart in a randomized and counterbalanced order. Explosive performance was assessed before, 24 and 48 hours after a low-volume, power-type training session (5 × 4 jump squats at 40% 1RM with 3 minutes rest), as well as before and after 24 and 48 hours of rest (control). Dependent variables were as follows: countermovement jump (CMJ), reactive strength index (RSI) during a drop jump, leg press maximum isometric force, and rate of force development (RFD) at 3 time windows: 0-100, 0-200, and 0-300 milliseconds. Analysis of variance revealed no changes in the control conditions. In contrast after training, CMJ was improved by 5.1 ± 1.0% and 3.0 ± 1.0% at 24 and 48 hours, respectively, compared with baseline. The RSI improved by 10.7 ± 2.1% only at 24 hours. The RFD increased at all time windows at 24 hours (range of improvement: 9.7 ± 3.4% to 18.3 ± 4.1%, p < 0.01). However, at 48 hours, improvement was only seen in RFD0-100 (9.8 ± 3.1%, p < 0.01). These findings suggest that a low-volume, power-type training session results in delayed enhancement of explosive muscle performance, which is greatest at 24 hours after the activity. Athletes are advised to perform power-type training 1 day before competition or a high-quality training session to improve their performances.

Effects of Resistance Exercise and Protein on Body Composition Following Weight Loss

Background: Research indicates that weight loss programs are effective for reducing body weight temporarily, but weight maintenance studies have been almost uniformly unsuccessful in preventing weight regain.Methods: Subjects who completed a 6-month weight loss study were invited to continue with a weight maintenance program. The weight loss study examined the effects of exercise (20 min strength, 20 min aerobics, twice weekly) and nutrition (1,200 to 1,800 kcal·d−1, 2 daily meal replacement protein shakes) on body weight and body composition. Weight loss program completers experienced improvements (P &amp;lt; 0.05) in body weight, percent fat, fat mass, lean mass, waist girth, and hip girth. Subjects who participated in the weight maintenance program performed the same strength and aerobic exercise protocol, but discontinued caloric restriction and decreased daily meal replacement protein shakes from 2 to 1.Results: After 6 months on the weight maintenance program, participants experienced improvement (P &amp;lt; 0.05) in percent fat, fat mass, lean mass, waist girth, and hip girth, with no significant change in body weight. A subgroup of subjects who continued the weight maintenance program for an additional 3 months experienced additional improvement (P &amp;lt; 0.05) in percent fat, fat mass, lean mass, waist girth, and hip girth, with no significant change in body weight.Conclusion: These findings indicated that a postdiet weight maintenance program incorporating 2 weekly resistance and aerobic exercise sessions coupled with a daily meal replacement protein shake was effective for avoiding weight regain and for improving body composition, with concurrent fat mass decrease and lean mass increase.

Acute effect of resistance exercise performed at different intensities on urine loss in older women

IntroductionTo evaluate the acute effect of resistance exercise performed at different intensities (moderate and vigorous) on urine loss in older women with mixed and stress urinary incontinence.MethodsThe total of 16 older women with urinary incontinence underwent 2 sessions of resistance exercises involving different muscle groups. In a balanced crossover design, 1 of the 2 exercise intensities (12 or 6 repetitions maximum, RM) was applied in each session. The pad test was used to assess urine loss in the 2 sessions, with a weight increase of 2 g as the criterion. Differences in the pad test results between the sessions were compared with the use of the Wilcoxon test.ResultsThe mean pad weight was 0.69 ± 0.94 g at the intensity of 12RM and 0.50 ± 0.53 g at 6RM. In accordance with the cut-off adopted (2 g), only 2 of the 16 women lost urine. No significant difference in the pad test results (&lt;i&gt;p&lt;/i&gt; = 0.975) was observed between the 2 resistance exercise intensities.ConclusionsResistance exercise performed at different intensities (moderate and vigorous) did not cause urine loss in older women with urinary incontinence.

Increased skeletal muscle IL-15Rα is associated with myofibrillar protein synthesis in response to a single session of resistance exercise

Increased skeletal muscle IL-15Rα is associated with myofibrillar protein synthesis in response to a single session of resistance exercise

High versus Low doses of Anti-inflammatory Drugs Do Not Differentially Affect Muscle Molecular Response to Acute Resistance Exercise

PURPOSE: We recently reported that high doses of non-steroidal anti-inflammatory drugs (NSAIDs) attenuate resistance exercise-induced muscle hypertrophy in young adults. Yet, little is known about the molecular mechanisms behind this effect. The current study aimed to examine acute muscle molecular responses to resistance exercise during co- ingestion of high and low doses of anti-inflammatory drugs. METHODS: Thirty one young (age 18-35 years) healthy men and women were randomly assigned to daily consumption of high doses of ibuprofen (IBU; 1200 mg; n=15) or low doses of acetylsalicylic acid (ASA; 75 mg; n=16) during an 8-week training intervention. During this period, subjects performed 20 supervised resistance training sessions (4 x 7-12 repetitions) involving the knee extensor muscles. Gene expression and protein signaling of key muscle growth regulators were analyzed from skeletal muscle biopsies obtained before training/treatment and 3 hours after an acute resistance exercise session during week 4 of the intervention. Real-time qPCR procedures were employed to determine mRNA expression. Protein signaling was assessed using western blots. RESULTS: Gene expression of myostatin (0.4-fold; p>0.0005), MuRF-1 (0.8-fold; p=0.015) and FoxO3 (0.6-fold; p>0.0005) decreased in response to the resistance exercise bout, with no difference across groups. Gene expression of IL-6 and STAT3 were unaltered. Protein phosphorylation of p70S6K increased (24-fold, P>0.0005) in response to the resistance exercise bout, with no difference across groups. Protein phosphorylation of STAT3 remained unchanged. CONCLUSIONS: These results show that high and low doses of NSAIDs do not differentially affect exercise-induced changes in gene expression and protein signaling for key markers of muscle growth in young adults. We therefore conclude that these acute markers do not seem to explain the negative effects of high doses of NSAIDs on muscle hypertrophy.

Single resistance training session leads to muscle damage without isometric strength decrease

Here we demonstrated that a single resistance exercise session causes muscle damage, delayed onset muscle soreness (DOMS), higher creatine kinase (CK) and lactate dehydrogenase (LDH) activity, and increased IL-6 concentration without changes in muscle strength. Sixteen healthy untrained subjects performed five exercises consisting of three sets of 10 maximum repetitions for each exercise and 1 minute rest period between sets and exercises. Blood samples were taken after 30 minutes, 24, 48 and 72 hours and before exercise. Muscular performance was assessed by maximum isometric strength (MIS) before, 24h, 48h and 72h exercise session. We have concluded that the single resistance exercise session, performed on this study, led to muscle damage and this variable cannot be evaluated through maximal isometric strength. Among those markers, CK was more sensitive to muscle damage. This information might be important for adequate recovery between training sessions.