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.
Nicholas A. Ratamess, Jay R. Hoffman, Ryan Ross, Miles Shanklin, Avery D. Faigenbaum and Jie Kang
Patrick Delisle-Houde, Nathan A. Chiarlitti, Ryan E.R. Reid and Ross E. Andersen
Purpose: To determine the predictability of common laboratory/field and novel laboratory tests for skating characteristics in Canadian college ice hockey players. Methods: A total of 18 male hockey players from the university’s varsity hockey team age 20–25 y (height 180.7 [6.4] cm, weight 87.1 [6.7] kg, and body fat 16.2% [4.0%]) completed common laboratory-/field-based testing (ie, standing long jump, vertical jump, off-ice proagility,
Marisa A. Colston, Gary B. Wilkerson, Hillary Dreyfus and Ryan Ross
Poor neuromechanical control and rapid fatigue of the core muscles are associated with elevated risk for core or lower extremity (CLE) injury. The purpose of this study was to identify preparticipation screening measures associated with both previous and subsequent CLE injuries among high school football players. Self-reported CLE injury history, core muscle endurance, and postural balance were strongly associated with CLE injury. Our findings demonstrated that the same risk categorization cut-points predicted both injury within the previous 12 months and subsequent season injury. Preseason screening results can be used to estimate CLE injury susceptibility among high school football players.
Chanel T. LoJacono, Ryan P. MacPherson, Nikita A. Kuznetsov, Louisa D. Raisbeck, Scott E. Ross and Christopher K. Rhea
Obstacle crossing, such as stepping over a curb, becomes more challenging with natural aging and could lead to obstacle-related trips and falls. To reduce fall-risk, obstacle training programs using physical obstacles have been developed, but come with space and human resource constraints. These barriers could be removed by using a virtual obstacle crossing training program, but only if the learned gait characteristics transfer to a real environment. We examined whether virtual environment obstacle crossing behavior is transferred to crossing real environment obstacles. Forty participants (n = 20 younger adults and n = 20 older adults) completed two sessions of virtual environment obstacle crossing, which was preceded and followed by one session of real environment obstacle crossing. Participants learned to cross the virtual obstacle more safely and that change in behavior was transferred to the real environment via increased foot clearance and alterations in foot placement before and after the real environment obstacle. Further, while both age groups showed transfer to the real environment task, they differed on the limb in which their transfer effects applied. This suggests it is plausible to use virtual reality training to enhance gait characteristics in the context of obstacle avoidance, potentially leading to a novel way to reduce fall-risk.
Cheryl Carnoske, Christine Hoehner, Nicholas Ruthmann, Lawrence Frank, Susan Handy, James Hill, Sherry Ryan, James Sallis, Karen Glanz and Ross Brownson
Although public support for physical activity-friendly Traditional Neighborhood Developments (TNDs) appears to be growing, information is lacking on private sector perspectives and how economic factors (eg, fuel prices) might influence the development and sale of TNDs.
A sample of realtors from the National Association of Realtors (n = 4950) and developers from the National Association of Home Builders (n = 162) were surveyed in early 2009 to assess factors influencing homebuyers' decisions; incentives and barriers to developing TNDs; effects of depressed housing market conditions and financing on sales; trends in buying; and energy considerations (eg, green building).
Realtors believed that homebuyers continue to rank affordability, safety and school quality higher than TND amenities. Developers reported numerous barriers to TNDs, including the inability to overcome governmental/political hurdles, lack of cooperation between government agencies, and lack of market demand. Yet, realtors believed clients are increasingly influenced by gas and oil prices, and developers reported that clients are looking for energy efficient homes, reduced commute time, and walkable neighborhoods. Respondents reported consumers are more interested in living in a TND than 5 years ago.
Activity-friendly TNDs appear to be increasing in demand, but developers and realtors reported significant barriers to creating these communities.