We compared immediate post-exercise whey protein (WP, 500 mg) versus l-leucine (LEU, 54 mg) feedings on skeletal muscle protein synthesis (MPS) mechanisms and ribosome biogenesis markers 3 h following unilateral plantarflexor resistance exercise in male, Wistar rats (~250 g). Additionally, in vitro experiments were performed on differentiated C2C12 myotubes to compare nutrient (i.e., WP, LEU) and ‘exercise-like’ treatments (i.e., caffeine, hydrogen peroxide, and AICAR) on ribosome biogenesis markers. LEU and WP significantly increased phosphorylated-rpS6 (Ser235/236) in the exercised (EX) leg 2.4-fold (P < 0.01) and 2.7-fold (P < 0.001) compared to the non-EX leg, respectively, whereas vehicle-fed control (CTL) did not (+65 %, P > 0.05). Compared to the non-EX leg, MPS levels increased 32 % and 52 % in the EX leg of CTL (P < 0.01) and WP rats (P < 0.001), respectively, but not in LEU rats (+15 %, P > 0.05). Several genes associated with ribosome biogenesis robustly increased in the EX versus non-EX legs of all treatments; specifically, c-Myc mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA, Npm1 mRNA, Fb1 mRNA, and Xpo-5 mRNA. However, only LEU significantly increased 45S pre-rRNA levels in the EX leg (63 %, P < 0.001). In vitro findings confirmed that ‘exercise-like’ treatments similarly altered markers of ribosome biogenesis, but only LEU increased 47S pre-rRNA levels (P < 0.01). Collectively, our data suggests that resistance exercise, as well as ‘exercise-like’ signals in vitro, acutely increase the expression of genes associated with ribosome biogenesis independent of nutrient provision. Moreover, while EX with or without WP appears superior for enhancing translational efficiency (i.e., increasing MPS per unit of RNA), LEU administration (or co-administration) may further enhance ribosome biogenesis over prolonged periods with resistance exercise.

Next-generation RNA sequencing was employed to determine the acute and subchronic impact of peristaltic pulse external pneumatic compression (PEPC) of different target inflation pressures on global gene expression in human vastus lateralis skeletal muscle biopsy samples. Eighteen (N = 18) male participants were randomly assigned to one of the three groups: (1) sham (n = 6), 2) EPC at 30-40 mmHg (LP-EPC; n = 6), and 3) EPC at 70-80 mmHg (MP-EPC; n = 6). One hour treatment with sham/EPC occurred for seven consecutive days. Vastus lateralis skeletal muscle biopsies were performed at baseline (before first treatment; PRE), 1 h following the first treatment (POST1), and 24 h following the last (7th) treatment (POST2). Changes from PRE in gene expression were analyzed via paired comparisons within each group. Genes were filtered to include only those that had an RPKM ≥ 1.0, a fold-change of ≥1.5 and a paired t-test value of <0.01. For the sham condition, two genes at POST1 and one gene at POST2 were significantly altered. For the LP-EPC condition, nine genes were up-regulated and 0 genes were down-regulated at POST1 while 39 genes were up-regulated and one gene down-regulated at POST2. For the MP-EPC condition, two genes were significantly up-regulated and 21 genes were down-regulated at POST1 and 0 genes were altered at POST2. Both LP-EPC and MP-EPC acutely alter skeletal muscle gene expression, though only LP-EPC appeared to affect gene expression with subchronic application. Moreover, the transcriptome response to EPC demonstrated marked heterogeneity (i.e., genes and directionality) with different target inflation pressures.

We employed next generation RNA sequencing (RNA‐seq) technology to determine the impact of peristaltic pulse external pneumatic compression (EPC) at high and low target inflation pressures on global gene expression in human vastus lateralis skeletal muscle biopsy samples. Methods Eighteen (N=18) apparently healthy male subjects participated in this study and were randomly assigned to one of three groups: 1) sham (n=6), 2) EPC with target inflation pressures of 30 mmHg (n=6) and 3) EPC with target inflation pressures of 70–80 mmHg (n=6). Daily treatment with sham or EPC was given for 7 consecutive days with each treatment lasting 1 h. Vastus lateralis skeletal muscle biopsy samples were harvested at baseline (48 hours before the first treatment; T1), 1 h following the first treatment (T2), and 24 hours following the last (7 th ) treatment (T3). 3,613 annotated genes with an RPKM value of ≥ 1.0 were selected for analysis. Change from baseline (T1) in gene expression was analyzed via paired comparisons within each group (i.e. T2 vs. T1 and T3 vs. T1). The 3,613 genes were then further filtered to include only those that had a fold‐change (FC) of ≥ 1.5 and a paired t‐test value of <0.01. Results For the sham condition, only 2 genes at T2 (SF3B5, FIS1) and 1 gene at T1 (LYPLA2) were identified as being significantly altered compared to baseline with time. For the 30 mmHg EPC condition, 9 genes were found to be significantly upregulated at T2 and 39 genes were found to be significantly upregulated at T3 compared to baseline. Two of these genes were significantly upregulated at both T2 and T3 (ARRDC2 and DYNLL2). Only one gene was found to be significantly downregulated compared to baseline in the 30 mmHg EPC group (TIMM10) and this was observed at T3. For the 70–80 mmHg EPC condition, 2 genes were found to be significantly upregulated (HBA1, HBA2) and 21 genes were found to be significantly downregulated at T2 compared to baseline. At T3, only 1 gene was found to be significantly altered (downregulation of DNAJB5) in the 70–80 mmHg EPC group. Interestingly, VEGFA was found to be differentially regulated as its expression was significantly upregulated with 30 mmHg EPC at T3 and significantly downregulated with 70–80 mmHg EPC at T3. Follow up analyses respective to gene clusters of interest are presented herein. Conclusions In summary, a more dynamic alteration of skeletal muscle gene expression was observed with a lower (i.e. 30 mmHg) EPC target inflation pressure, particularly after 7 consecutive days of treatment. Moreover, altered genes tended to be upregulated with 30 mmHg EPC whereas genes tended to be downregulated with 70 mmHg. Support or Funding Information The authors would like to thank NormaTec (Newton Center, MA) for their partial financial support (50%) of this project through a contract awarded to J.S.M.

Inorganic nitrate ingestion has been posited to affect arterial blood pressure and vascular function.

Background Amino acid supplementation has been shown to potentially reduced exercise-induced muscle soreness. Thus, the purpose of this study was to examine if branched chain amino acid and carbohydrate (BCAACHO) versus carbohydrate-only sports drink (CHO) supplementation attenuated markers of muscle damage while preserving performance markers following 3 days of intense weight training. Methods Healthy resistance-trained males ( n = 30) performed preliminary testing (T1) whereby they: 1) donated a baseline blood draw, 2) performed knee extensor dynamometry to obtain peak quadriceps isometric and isokinetic torque as well as electromyography (EMG) activity at 60°/s and 120°/s, and 3) performed a one repetition maximum (1RM) barbell back squat. The following week participants performed 10 sets x 5 repetitions at 80 % of their 1RM barbell back squat for 3 consecutive days and 48 h following the third lifting bout participants returned for (T2) testing whereby they repeated the T1 battery. Immediately following and 24 h after the three lifting bouts, participants were randomly assigned to consume one of two commercial products in 600 mL of tap water: 1) BCAAs and CHO (3 g/d L-leucine, 1 g/d L-isoleucine and 2 g/d L-valine with 2 g of CHO; n = 15), or 2) 42 g of CHO only ( n = 15). Additionally, venous blood was drawn 24 h following the first and second lifting bouts and 48 h following the third bout to assess serum myoglobin concentrations, and a visual analog scale was utilized prior, during, and after the 3-d protocol to measure subjective perceptions of muscular soreness. Results There were similar decrements in 1RM squat strength and isokinetic peak torque measures in the BCAA-CHO and CHO groups. Serum myoglobin concentrations ( p = 0.027) and perceived muscle soreness ( p < 0.001) increased over the intervention regardless of supplementation. A group*time interaction was observed for monocyte percentages ( p = 0.01) whereby BCAA-CHO supplementation attenuated increases in this variable over the duration of the protocol compared to CHO supplementation. Conclusion BCAA-CHO supplementation did not reduce decrements in lower body strength or improve select markers of muscle damage/soreness compared to CHO supplementation over three consecutive days of intense lower-body training.

Dietary inorganic nitrate supplementation (e.g. beet juice) has been shown to improve exercise economy. This is thought to be due, in part, to reduced oxygen cost during exercise mediated by nitric oxide signaling. PURPOSE: We sought to determine if a red spinach extract (RSE) rich in nitrate content improved exercise economy during graded exercise testing (GXT). METHODS: Twelve (6 males, 6 females) recreationally trained subjects (aged 22.9 ± 2.0 years) participated in this double-blinded, placebo (PBO) controlled, crossover study. For each visit (separated by > 1 week), subjects reported at least 2 h post-prandial, had followed a low-nitrate diet for at least 48 hours and abstained from exercise, caffeine and alcohol for at least 24 hours. Procedures included baseline venipuncture, supplementation with RSE (1000mg) or PBO, passive rest for 90 minutes, GXT (Bruce protocol) and immediately post-GXT venipuncture. RESULTS: Humoral concentrations of nitrates were significantly elevated from baseline with RSE (from 10.2 ± 4.1 to 36.9 ± 8.2 μM; p<0.001) but not PBO (from 10.1 ± 2.4 to 9.1 ± 2.6μM). Neither GXT time-to-exhaustion nor VO2 peak were significantly different between conditions (9.5 ± 1.7 vs. 9.2 ± 1.3 min and 40.8 ± 7.1 vs. 41.1 ± 7.6 ml/kg/min for RSE and PBO, respectively). However, the ventilatory threshold was significantly higher with RSE compared to PBO (VO2, 2.55 ± 0.67 vs. 2.35 ± 0.73 L min; p=0.04). CONCLUSIONS: RSE improved the ventilatory threshold in recreationally trained subjects, though further research should be conducted to determine efficacy in endurance exercise performance.

Methods Male Sprague-Dawley rats (~9-10 weeks of age) were provided isocaloric amounts of either a KD (5.2 kcal/g, 20.2% protein, 10.3% carbohydrate, 69.5% fat; n = 50), WD (4.5 kcal/g, 15.2% protein, 42.7% carbohydrate, 42.0% fat; n = 66), or StdChow (3.1 kcal/g, 24.0% protein, 58.0% carbohydrate, 18.0% fat n = 10) for 6 weeks with daily food intake and body weights recorded. After the animals were sacrificed, 4 different fat depots were weighed and serum was collected in subsets of each diet for further investigation.

Methods This study examined the effects of KD versus WD on the anabolic response to resistance exercise using a rodent leg-kicking resistance exercise model. Male Sprague-Dawley rats (~9-10 weeks of age) were provided isocaloric amounts of either a KD (5.2 kcal/g, 20.2% protein, 10.3% carbohydrate, 69.5% fat; n = 30) or WD (4.5 kcal/g, 15.2% protein, 42.7% carbohydrate, 42.0% fat; n = 32) for 6 weeks. During week 7, the right-leg plantarflexor muscles of each rat were acutely exercised under isoflurane anesthesia using high-frequency electrical stimulations (4 sets of 8 repetitions with 2 min recovery between sets). Rats were then sacrificed at 90 min (n = 8 per group), 180 min (n = 8 per group), or 270 min (n = 8 per group) following exercise and intraperitoneal puromycin injections were provided 30 min prior to each sacrifices as a tracer for muscle protein synthesis (MPS). A subset of unexercised limbs from WD (n = 8) and KD (n = 8) were used as a nonexercise (non-EX) control comparison. Results There was a main time effect for MPS, as it was significantly greater at 90, 180 and 270 min in both groups versus the non-EX condition (p < 0.001), although there was no between group effect (p = 0.59) or group*time interaction (p = 0.87). There was a main time effect for phosphorylated (p)-4E-BP1 (Thr37/46), as it was significantly greater at 90, 180 and 270 min in both groups versus the non-EX condition (p = 0.001), although there was no between group effect (p = 0.85) or group*time interaction (p = 0.93). There was a main time effect for p-rps6 (Ser235/236), as it was significantly greater at 90, 180 and 270 min in both groups versus the non-EX condition (p = 0.002), although there was no between group effect (p = 0.99) or group*time interaction (p = 0.79). There was no time effect (p = 0.31), between group effect (p = 0.42) or group*time interaction (p = 0.22) for p-AMPKa (Thr172).

We examined whether acute and/or chronic skeletal muscle anabolism is impaired with a low-carbohydrate diet formulated to elicit ketosis (LCKD) vs. a mixed macronutrient Western diet (WD). Male Sprague-Dawley rats (9-10 wk of age, 300-325 g) were provided isoenergetic amounts of a LCKD or a WD for 6 wk. In AIM 1, basal serum and gastrocnemius assessments were performed. In AIM 2, rats were resistance exercised for one bout and were euthanized 90-270 min following exercise for gastrocnemius analyses. In AIM 3, rats voluntarily exercised daily with resistance-loaded running wheels, and hind limb muscles were analyzed for hypertrophy markers at the end of the 6-wk protocol. In AIM 1, basal levels of gastrocnemius phosphorylated (p)-rps6, p-4EBP1, and p-AMPKα were similar between diets, although serum insulin (P < 0.01), serum glucose (P < 0.001), and several essential amino acid levels (P < 0.05) were lower in LCKD-fed rats. In AIM 2, LCKD- and WD-fed rats exhibited increased postexercise muscle protein synthesis levels (P < 0.0125), but no diet effect was observed (P = 0.59). In AIM 3, chronically exercise-trained LCKD- and WD-fed rats presented similar increases in relative hind limb muscle masses compared with their sedentary counterparts (12-24%, P < 0.05), but there was no between-diet effects. Importantly, the LCKD induced "mild" nutritional ketosis, as the LCKD-fed rats in AIM 2 exhibited ∼1.5-fold greater serum β-hydroxybutyrate levels relative to WD-fed rats (diet effect P = 0.003). This study demonstrates that the tested LCKD in rodents, while only eliciting mild nutritional ketosis, does not impair the acute or chronic skeletal muscle hypertrophic responses to resistance exercise.

Methods Apparently healthy resistance trained males (n = 30) were randomized to either a BCAA group or the CHO control group. Participants performed preliminary testing (T1) to derive peak quadriceps isometric torque, peak quadriceps isokinetic torque (60o and 120o per second), and a 1RM barbell back squat. The following week, the participants performed 10x5 repetitions at 80% of their 1RM barbell back squat for 3 consecutive days. During this experimental intervention antecubital blood was drawn to assess serum myoglobin concentrations, in addition a visual analog scale was utilized in order to measure subjective perceptions of muscular soreness. 48 hours following the third bout of exercise, participants performed post testing (T2) like T1 testing and donated a final blood draw.