Terence G. Favero

Glutathione Modulates Ryanodine Receptor from Skeletal Muscle Sarcoplasmic Reticulum EVIDENCE FOR REDOX REGULATION OF THE Ca2+ RELEASE MECHANISM

In this report, we demonstrate the ability of the cellular thiol glutathione to modulate the ryanodine receptor from skeletal muscle sarcoplasmic reticulum. Reduced glutathione (GSH) inhibited Ca2+-stimulated [3H]ryanodine binding to the sarcoplasmic reticulum and inhibited the single-channel gating activity of the reconstituted Ca2+ release channel. The effects of GSH on both the [3H]ryanodine binding and single-channel measurements were dose-dependent, exhibiting an IC50 of ∼2.4 mM in binding experiments. Scatchard analysis demonstrated that GSH decreased the binding affinity of ryanodine for its receptor (increased Kd) and lowered the maximal binding occupancy (Bmax). In addition, GSH did not modify the Ca2+ dependence of [3H]ryanodine binding. In single-channel experiments, GSH (5-10 mM), added to the cis side of the bilayer lipid membrane, lowered the open probability (Po) of a Ca2+ (50 μM)-stimulated Ca2+ channel without modifying the single-channel conductance. Subsequent perfusion of the cis chamber with an identical buffer, containing 50 μM Ca2+ without GSH, re-established Ca2+-stimulated channel gating. GSH did not inhibit channel activity when added to the trans side of the bilayer lipid membrane. Similar to GSH, the thiol-reducing agents dithiothreitol and β-mercaptoethanol also inhibited high affinity [3H]ryanodine binding to sarcoplasmic reticulum membranes. In contrast to GSH, glutathione disulfide (GSSG) was a potent stimulator of high affinity [3H]ryanodine binding and it also stimulated the activity of the reconstituted single Ca2+ release channel. These results provide direct evidence that glutathione interacts with reactive thiols associated with the Ca2+ release channel/ryanodine receptor complex, which are located on the cytoplasmic face of the SR, and support previous observations (Liu, G, Abramson, J. J., Zable, A. C., and Pessah, I. N. (1994) Mol. Pharmacol. 45, 189-200) that reactive thiols may be involved in the gating of the Ca2+ release channel.

TRAINING-INDUCED ALTERATIONS IN LACTATE DEHYDROGENASE REACTION KINETICS IN RATS: A RE-EXAMINATION

The kinetics and the isozyme composition of lactate dehydrogenase (LDH) were measured in rat plantaris muscle during a 26 week endurance‐training program. Alterations in the LDH isozyme pattern were detectable after 6 weeks as the percentage of the M4 isozyme was reduced from 89 to 76% and the total percentage of M subunits compared with H subunits declined by 8%. At 16 weeks, M4 accounted for only 62% of the total. The replacement of M with H subunits continued when training was prolonged as M4 represented only 52% of the total isozymes at 26 weeks. Conversely, training for 6 and 16 weeks produced no changes in either Vmax or Km. At 26 weeks, these values declined for both the forward (pyruvate to lactate) and backward reactions. The rate constants for both reactions were also reduced. These data suggest that changes in LDH isozyme pattern do not contribute significantly to the enhancement of lactate oxidation that may occur after training. They also suggest that the functional significance of alterations in LDH structure and/or function are best determined from analysis of the overall reaction kinetics as opposed to individual characteristics such as the isozyme pattern, Km or Vmax.

Active review sessions can advance student learning

Traditional review sessions are intended to help students learn and prepare for upcoming exams. Most sessions are passive question and answer sessions that look backward at content deficits rather than advancing student learning. By incorporating active and cooperative learning approaches during a review session, students are able to recognize critical concepts and better prepare for physiological problem solving. Active review sessions help students prioritize the knowledge and develop the thinking skills will be required of them on the exam.

Physiological and Technical Demands of No Dribble Game Drill in Young Basketball Players.

Abstract Conte, D, Favero, TG, Niederhausen, M, Capranica, L, and Tessitore, A. Physiological and technical demands of no dribble game drill in young basketball players. J Strength Cond Res 29(12): 3375–3379, 2015—This study assessed the physiological and technical demands of no dribble game drill (NDGD) in comparison with a regular drill (RD). Twenty-three young basketball players performed RDs and NDGDs in a random order. All basketball rules were followed for RDs, whereas dribbling was not permitted for NDGDs. The independent variable was the drill condition, and the dependent variables were percentage of maximal heart rate (%HRmax), rate of perceived exertion (RPE), Edwards training load (TL), and the following technical actions (TAs): pass (total, correct, wrong, and percent of correct passes), shot (total, scored, missed, and percent of made shots), interception, steal, turnover, and rebound. Wilcoxon signed-rank tests were applied to assess differences between NDGD and RD conditions for each dependent variable, and the level of statistical significance was set at p ⩽ 0.05. Results showed higher values for %HRmax (p = 0.007), Edwards TL (p = 0.006), and RPE (p = 0.027) in NDGD compared with RD condition. Technical action analysis revealed higher values in NDGD than RD for total (p = 0.000), correct (p = 0.000), and wrong pass (p = 0.005), and interception (p = 0.001), whereas no significant differences were found for the other TAs. The main finding of this study was that NDGD condition elicited a greater physiological demand and a higher number of passes and interceptions than the RD one. Basketball coaches should consider the NDGD as a viable method to increase the physiological load of their training sessions and to teach passing skills in a game-based situation.

Determinants of the effectiveness of fast break actions in elite and sub-elite Italian men’s basketball games

The aim of this study was to examine the determinants of successful and unsuccessful fast-break (FB) actions in elite and sub-elite basketball games. Fifteen 1st-division (elite) and fifteen 3rd-division (sub-elite) Italian men’s championship games were analysed across two seasons (2012/2013 and 2013/2014). A binary logistic regression analysis was performed, and the fast-break outcome (successful vs. unsuccessful) was adopted as the dependent variable separately in both elite and sub-elite games. FB execution (initiation, advance and completion phases), typology (primary and secondary break) and the number of players involved (equal number or superiority) were used as independent variables. The results showed that the rate of success of FB actions was 63.5% and 59.7% in elite and sub-elite games, respectively. Moreover, successful FBs were more likely to be completed in the lane in relation to unsuccessful ones in both elite and sub-elite games (p<0.05). Finally, descriptive statistics showed that both elite and sub-elite teams executed FBs similarly. This study highlighted that completion zone was the only predictor of a successful fast break in basketball, while the typology and number of players involved did not predict fast break effectiveness. Moreover, elite and sub-elite teams executed fast break actions similarly. These findings might be useful for basketball coaches to optimize the training of FB actions.

Effect of different number of players and training regimes on physiological and technical demands of ball-drills in basketball

Abstract This study aimed to analyse the effects of two factors (number of players and training regimes) on players’ physiological and technical demands in basketball ball-drills. Twenty-one young basketball players performed four different ball-drills (two levels for each factor). The number of players involved was 2vs2 and 4vs4, while ball-drill regimes were continuous and intermittent. Physiological demand was assessed using the percentage of maximal heart rate (%HRmax), Edwards’ training load and rating of perceived exertion (RPE). Furthermore, the following technical actions were collected: dribbles, steals, rebounds, turnovers, passes (total, correct, wrong and % of correct pass) and shots (total, scored, missed and % of made shot). A 2 × 2 (number of players × regime) two-way ANOVA with repeated measures was applied for physiological parameters and technical actions. The 2vs2 condition showed higher %HRmax (P < 0.001), Edwards’ training load (P < 0.001), RPE (P < 0.001), number of dribbles (P < 0.001), rebounds (P < 0.001), passes [total (P = 0.005) and correct (P = 0.005)] and shots [total (P < 0.001) scored (P < 0.001) and missed (P < 0.001)] than 4vs4. Moreover, the continuous regime revealed higher %HRmax (P < 0.001), Edwards’ training load (P < 0.001), RPE (P = 0.006) and dribbles (P < 0.001) than the intermittent regime. This study showed that both number of players and regime are useful variables able to modify basketball ball-drills workload.

Student Exam Analysis (Debriefing) Promotes Positive Changes in Exam Preparation and Learning.

Traditional exam review sessions, typically conducted orally and in class by the instructor, are intended to identify the most frequently missed or problematic question with the intent of helping students perform better on subsequent exams. The shortcoming of this instructor-led activity is that it tends to focus on issues with content or understanding rather than helping the individual student prevent or avoid similar mistakes on future exams. Here, we report that students who performed a more comprehensive out-of-class exam debrief after the first exam significantly improve their exam performance compared with students that did not conduct the exam debrief. We also identify the most common mistakes that students make on exams and the most frequent self-selected strategies to improve their learning. By having students focus on missed questions coupled with addressing deficiencies in their test preparation strategies and behaviors, they likely engage in more self-regulated learning to better prepare for exams and avoid repeating past mistakes.

Investigating the game-related statistics and tactical profile in NCAAdivision I men’s basketball games

The aim of this study was to analyze the game-related statistics and tactical profile in winning and losing teams in NCAA division I men’s basketball games. Twenty NCAA division I men’s basketball close (score difference: 1-9 points) games were analyzed during the 2013/14 season. For each game, the game-related statistics were collected from the official teams’ box scores. Number of ball possessions, offensive and defensive ratings and the Four Factors (effective field goal percentage; offensive rebounding percentage, recovered balls per ball possession, free throw rate) were also calculated. The tactical parameters evaluated were: ball reversal, dribble in key area, post entry, on-ball screen, off-ball screen, and hand off. Differences between winning and losing teams were calculated using a magnitude-based approach. Winning teams showed a likely higher percentage of 3-point goals made, number of defensive rebounds and steals and a very likely higher number of free throws made and free throws attempted. Furthermore, winning teams showed a likely higher team offensive rating and effective field goal percentage and a very likely higher free throw rate compared to losing teams. Finally, the results revealed a likely higher number of ball reversals and post entries in winning teams compared to losing teams. This study highlighted the game-related statistics and the tactical actions differentiating between winning and losing teams in NCAA Division I men’s basketball close games. Coaches should use these results to optimize their training sessions, focusing on those variables that might increase the possibility to win close games.

Performance profile of NCAA Division I men’s basketball games and training sessions

This study aimed to analyse live and stoppage time phases, their ratio, and action played on half and full court in college basketball games. Differences were assessed for the entire games and between halves. Moreover, differences of the live/stoppage time ratio were analysed between games and game-based conditioning drills. Ten games as well as fifteen defensive, fourteen offensive and six scrimmage-type drills of the same division I mens college team (13 players) were analysed using time-motion analysis technique. Live and stoppage time were classified in five classes of duration: 1-20, 21-40, 41-60, 61-80, >80 seconds. Half court actions started and finished in the same half court. Full court actions were classified as transfer (TR) phases when at least 3 teammates crossed the mid-court line. TR phases were then classified in 5 classes of frequency: 1TR, 2TR, 3TR, 4TR, and >4TR. The results revealed no statistically significant differences between games or between halves for the considered parameters. The only significant difference was observed for live/stoppage time ratio between halves (p<0.001). Furthermore, a significant difference of the live/stoppage ratio was found between games and game-based drills (p<0.01). Post-hoc analysis demonstrated significant differences of scrimmage-type drills in comparison to games, and defensive and offensive drills (p<0.05), whereas no differences emerged for the other pairwise comparisons. The absence of differences between games in the analysed parameters might be important to characterize the model of performance in division I mens college games. Furthermore, these results encourage coaches to use game-based conditioning drills to replicate the LT/ST ratio documented during games.

Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

This study aimed to assess the basketball ball-drills workload analyzing: (1) the effect of varying the number of players involved on physiological and technical demands; (2) the temporal changes in players’ responses across bouts; and (3) the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1) completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax) and ratings of perceived exertion (RPE) were collected. Technical actions (TAs) (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers) were calculated through notational analysis. Players’ genitalia development (GD) and pubic hair (PH) growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018), RPE (p = 0.042), dribbles (p = 0.007), shots (p = 0.003), and rebounds (p = 0.006) in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005) and number of passes (p = 0.020) between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age.