Whey protein is a supplemental protein source often used by athletes, particularly those aiming to gain muscle mass; however, direct evidence for its efficacy in stimulating muscle protein synthesis (MPS) is lacking. We aimed to determine the impact of consuming whey protein on skeletal muscle protein turnover in the post-exercise period. Eight healthy resistance-trained young men (age=21+/-1 .0 years; BMI=26.8+/-0.9 kg/m2 (means+/-SE)) participated in a double-blind randomized crossover trial in which they performed a unilateral leg resistance exercise workout (EX: 4 sets of knee extensions and 4 sets of leg press; 8-10 repetitions/set; 80% of maximal), such that one leg was not exercised and acted as a rested (RE) comparator. After exercise, subjects consumed either an isoenergetic whey protein plus carbohydrate beverage (WHEY: 10 g protein and 21 g fructose) or a carbohydrate-only beverage (CHO: 21 g fructose and 10 g maltodextran). Subjects received pulse-tracer injections of L-[ring-2H5]phenylalanine and L-[15N]phenylalanine to measure MPS. Exercise stimulated a rise in MPS in the WHEY-EX and CHO-EX legs, which were greater than MPS in the WHEY-RE leg and the CHO-RE leg (all p<0.05), respectively. The rate of MPS in the WHEY-EX leg was greater than in the CHO-EX leg (p<0.001). We conclude that a small dose (10 g) of whey protein with carbohydrate (21 g) can stimulate a rise in MPS after resistance exercise in trained young men that would be supportive of a positive net protein balance, which, over time, would lead to hypertrophy.

The aim of this study was to investigate the ergogenic potential of arginine on NO synthesis, muscle blood flow, and skeletal muscle protein synthesis (MPS). Eight healthy young men (22.1 ± 2.6 y, 1.79 ± 0.06 m, 76.6 ± 6.2 kg; mean ± SD) participated in 2 trials where they performed a bout of unilateral leg resistance exercise and ingested a drink containing either 10 g essential amino acids with 10 g l-arginine (ARG) or an isonitrogenous control (CON). Femoral artery blood flow of both the nonexercised and exercised leg was measured continuously using pulsed-wave Doppler ultrasound, while rates of mixed and myofibrillar MPS were determined using a primed continuous infusion of L-[ring-(13)C(6)] or L-[ring-(2)H(5)]phenylalanine. The plasma arginine concentration increased 300% during the ARG trial but not during the CON trial (P < 0.001). Plasma nitrate, nitrite, and endothelin-1, all markers of NO synthesis, did not change during either the ARG or CON trial. Plasma growth hormone increased to a greater degree after exercise in the ARG trial than CON trial (P < 0.05). Femoral artery blood flow increased 270% above basal in the exercised leg (P < 0.001) but not in the nonexercised leg, with no differences between the ARG and CON trials. Mixed and myofibrillar MPS were both greater in the exercised leg compared with the nonexercised leg (P < 0.001), but did not differ between the ARG and CON treatments. We conclude that an oral bolus (10 g) of arginine does not increase NO synthesis or muscle blood flow. Furthermore, arginine does not enhance mixed or myofibrillar MPS either at rest or after resistance exercise beyond that achieved by feeding alone.

Introduction Evidence of the benefit of distributed instruction and interleaved practice comes from studies using simple materials (e. g. word pairs). Furthermore, there is currently no evidence of the combined impact of these strategies in undergraduate medical education. The present study evaluated the impact of varying both instruction and practice schedules for the acquisition of ECG interpretation skills. Methods We conducted a 2 × 2 factorial study with two levels of instruction (massed and distributed) and two levels of practice (interleaved and blocked). A three-module introductory course in ECG interpretation was delivered to 80 first year medical undergraduate students. Students were assigned to one of four Instruction-Practice conditions: Massed-Interleaved, Massed-Blocked, DistributedInterleaved and Distributed-Blocked. Learning was evalu- Results End of module mean scores showed that distributed instruction was consistently superior to massed instruction (52% vs 42%, p < 0.01). However, there was no effect of practice and no interaction between teaching and practice methods. The delayed final test scores revealed an advantage for blocked over mixed practice (34% vs 24%, p < 0.05) and distributed over massed instruction (34% vs 24%, p < 0.05). Discussion These results suggest that these popular strategies may have varying effects with complex learning materials. Further research is required to understand how these strategies affect the learning of simple and very complex skills.Keywords Distributed and massed instruction · Interleaved and blocked practice schedule · ECG interpretation · Learning What this paper addsAlthough there is evidence from experimental studies that distributing instruction over time and interleaving the sequence of practice to include items from multiple categories can have significant positive effects on learning, these strategies are not widely adopted. Importantly, the impact of both strategies has not been evaluated in medicine. This study contributes to our understanding of the impact of these strategies in a more applied education setting. Our findings suggest that interleaved practice may only become effective after sufficient mastery of the materials has occurred.

Oral anticoagulation is the mainstay of therapy for stroke prevention in patients with atrial fibrillation (AF). Vitamin K antagonists such as warfarin have many drawbacks that reduce their uptake, safety and effectiveness. The ROCKET AF trial compared rivaroxaban (20 mg/day; 15 mg/day in patients with creatinine clearance 30-49 ml/min) with dose-adjusted warfarin (international normalized ratio 2-3) in 14,264 patients with AF and a prior history of stroke or at least two other additional risk factors for stroke. The ROCKET AF trial demonstrated the noninferiority of rivaroxaban compared with warfarin for the prevention of stroke and systemic embolism, with a similar rate of major bleeding and a substantial reduction in intracranial hemorrhage. These results, in conjunction with its convenient once-daily dosing regimen, make rivaroxaban an attractive alternative to warfarin for stroke prevention in AF.

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