David Bellar

Serum insulin like growth factor-1 is associated with working memory, executive function and selective attention in a sample of healthy, fit older adults

The present study examined the association between serum insulin like growth factor-1 (IGF-1) concentrations and cognitive function in a sample of healthy, fit older adults (age: 70.8±9.3 years, body mass index (BMI): 27.3±5.7). Participants reported to the laboratory and basic anthropometric data were collected, followed by a fasted blood draw to quantify serum IGF-1. Participants then underwent cognitive testing that included the Mini-Mental Status Exam (MMSE), Trail Making Test A and B, Ruffs 2 and 7 test of selective attention and Letter Number Sequencing. Results showed the participants were generally cognitively intact (MMSE 27.6±1.8). Significant partial correlations (controlled for age, gender and years of education) emerged between serum IGF-1 concentrations and the total (r=0.381, P=0.030) and longest trial (r=0.455, P=0.011) on Letter Number Sequencing. Similar partial correlations yielded significant relationships between serum IGF-1 and Ruffs Automatic Detection Errors (r=-0.495, P=0.006), Controlled Speed Errors (r=-0.598, P=0.002) and errors made on the Trial Making Test part B (r=-0.466, P=0.010). These findings suggest that fasting levels of serum IGF-1 are related to higher levels of cognitive performance in healthy older adults, including working memory, selective attention and executive function. Further work is needed to more clearly determine possible mechanisms.

THE EFFECTS OF COMBINED ELASTIC- AND FREE-WEIGHT TENSION VS. FREE-WEIGHT TENSION ON ONE-REPETITION MAXIMUM STRENGTH IN THE BENCH PRESS

Bellar, DM, Muller, MD, Barkley, JE, Kim, C-H, Ida, K, Ryan, EJ, Bliss, MV, and Glickman, EL. The effects of combined elastic- and free-weight tension vs. free-weight tension on one-repetition maximum strength in the bench press J Strength Cond Res 25(2): 459-463, 2011-The present study investigated the effects of training combining elastic tension, free weights, and the bench press. Eleven college-aged men (untrained) in the bench press participated in the 13-week study. The participants were first given instructions and then practiced the bench press, followed by a one-repetition maximum (1RM) test of baseline strength. Subjects were then trained in the bench press for 3 weeks to allow for the beginning of neural adaptation. After another 1RM test, participants were assigned to 1 of 2 conditions for the next 3 weeks of training: 85% Free-Weight Tension, 15% Elastic Tension (BAND), or 100% Free-Weight Tension (STAND). After 3 weeks of training and a third 1RM max test, participants switched treatments, under which they completed the final 3 weeks of training and the fourth 1RM test. Analysis via analysis of covariance revealed a significant (p ≤ 0.05) main effect for time and interaction effect for Treatment (BAND vs. STAND). Subsequent analysis via paired-samples t-test revealed the BAND condition was significantly better (p = 0.05) at producing raw gains in 1RM strength. (BAND 9.95 ± 3.7 kg vs. STAND 7.56 ± 2.8 kg). These results suggest that the addition of elastic tension to the bench press may be an effective method of increasing strength.

The Effects of Low-Dose Caffeine on Perceived Pain During a Grip to Exhaustion Task

Bellar, D, Kamimori, GH, and Glickman, EL. The effects of low-dose caffeine on perceived pain during a grip to exhaustion task. J Strength Cond Res 25(5): 1225-1228, 2011-This double-blind, placebo-controlled, within-subject experiment examined the effects of low-dose caffeine on pain reported during an exhaustive grip task. The grip task consisted of holding a metal block attached to standard Olympic weight plates with the arm at the side until the participants could no longer maintain their grip. Apparently healthy recreationally trained college-aged adults (men, n = 5; women, n = 5) were given either a piece of Stay Alert™ gum that delivered 85% of the effective dose of 100 mg of caffeine in 5 minutes or an identical placebo gum that contained no caffeine. Subsequently, pain perception and ratings of perceived exertion were recorded during an exhaustive grip task every 15 seconds and the overall time to exhaustion. No significant difference was found in time to exhaustion between treatments. A significant main effect of treatment for reported pain (p < 0.001, Φ = 0.377) was observed. Thus, in a population of recreationally trained college-aged adults, low-dose caffeine may attenuate the individuals perception of pain during a grip to exhaustion task.

Reliability of the measurement of stroke volume using impedance cardiography during acute cold exposure.

INTRODUCTION It is well documented that cardiovascular alterations occur during acute cold exposure (ACE). Interindividual variability is present, due mainly to body size differences, gender, and age. However, no study has evaluated stroke volume in the same individual twice in the same ambient conditions (i.e., test-retest reliability). Impedance cardiography (ICG) has become a popular method to acquire hemodynamic data in both clinical and applied physiology settings. Further, ICG does not interfere with other dependent variables such as oxygen consumption. Therefore, based on the uniqueness of the methodology, we sought to test reliability in this technology at 5 degrees C for 65 min on two separate occasions. METHODS Nine young men underwent two 65-min trials of resting ACE, separated by at least 72 h. Volunteers were clothed in approximately one layer of clothing. Core and skin temperatures, oxygen consumption, and central hemodynamics were measured. RESULTS As expected, core and skin temperature decreased while oxygen consumption showed a modest increase over time. In both trials, stroke volume significantly increased over time as heart rate decreased. There was similarity within subjects and between trials for all variables, as assessed via bivariate correlations. CONCLUSION Cold increased stroke volume and decreased heart rate when subjects were pooled together, but each subject retained his individuality (minimal interindividual differences). Results suggest that impedance cardiography may be a reliable technique to use during acute cold exposure.

Efficacy of Potentiation of Performance Through Overweight Implement Throws on Male and Female High-school Weight Throwers

Judge, LW, Bellar, D, and Judge, M. Efficacy of potentiation of performance through overweight implement throws on male and female high school weight throwers. J Strength Cond Res 24(7): 1804-1809, 2010-The purpose of the investigation was to determine the acute effects of heavy implements on weight throw performance. Ten high-school weight throwers were recruited to participate. A within-subjects design was used to compare the difference between mean and peak distances achieved with the regulation weight after warm-up with regulation weight (control), 1.37-kg overweight (OVRWGHT1) and 2.27-kg overweight implement (OVRWGHT2). Analysis via repeated-measures analysis of variance revealed main effects for Treatment (p = 0.021) and Attempt (p = 0.015). The mean after the OVRWGHT1 treatment was the highest (14.52 ± 3.54 m) followed by OVRWGHT2 (14.22 ± 3.15 m) and the competition weight implement (STAND; 13.38 ± 2.98). Paired samples t-test for peak distance by treatment revealed that both OVRWGHT1 (p = 0.004) and OVRWGHT2 (p = 0.027) were significantly different from STAND. Post hoc testing revealed that both OVRWGHT1 (p = 0.025) and OVRWGHT2 (p = 0.007) resulted in a significant difference in perceived fatigue compared with STAND. The results suggest that using overweight implements as part of the warm-up may improve performance in high-school athletes.

Low-dose Caffeine Administered in Chewing Gum Does Not Enhance Cycling to Exhaustion

Ryan, EJ, Kim, C-H, Muller, MD, Bellar, DM, Barkley, JE, Bliss, MV, Jankowski-Wilkinson, A, Russell, M, Otterstetter, R, Macander, D, Glickman, EL, and Kamimori, GH. J Strength Cond Res 26(3): 844–850, 2012—Low-dose caffeine administered in chewing gum does not enhance cycling to exhaustion. The purpose of the current investigation was to examine the effect of low-dose caffeine (CAF) administered in chewing gum at 3 different time points during submaximal cycling exercise to exhaustion. Eight college-aged (26 ± 4 years), physically active (45.5 ± 5.7 ml·kg−1·min−1) volunteers participated in 4 experimental trials. Two pieces of caffeinated chewing gum (100 mg per piece, total quantity of 200 mg) were administered in a double-blind manner at 1 of 3 time points (−35, −5, and +15 minutes) with placebo at the other 2 points and at all 3 points in the control trial. The participants cycled at 85% of maximal oxygen consumption until volitional fatigue and time to exhaustion (TTE) were recorded in minutes. Venous blood samples were obtained at −40, −10, and immediately postexercise and analyzed for serum-free fatty acid and plasma catecholamine concentrations. Oxygen consumption, respiratory exchange ratio, heart rate, glucose, lactate, ratings of perceived exertion, and perceived leg pain measures were obtained at baseline and every 10 minutes during cycling. The results showed that there were no significant differences between the trials for any of the parameters measured including TTE. These findings suggest that low-dose CAF administered in chewing gum has no effect on TTE during cycling in recreational athletes and is, therefore, not recommended.

Effects of low-dose caffeine supplementation on early morning performance in the standing shot put throw

Abstract The purpose of the present investigation was to assess the efficacy of low-dose caffeine use for early morning performance in the shot put event. A double-blind, randomized, crossover design was used to investigate the effects of buccal caffeine supplementation on early morning shot put execution in nine inter-collegiate track and field athletes. In one condition the participants received a piece of caffeinated gum designed to deliver 100 mg of caffeine in a buccal manner, and in a second condition a placebo gum. The gum was chewed for 5 min before being discarded. Participants then completed the first psychomotor vigilance task followed by a series of five warm-up throws, followed by six attempts with a shot put (7.26 kg for males, 4.0 kg for females) measured for distance. The protocol ended with a final psychomotor vigilance task. A repeated-measures analysis of variance (treatment*time) was used to compare performance between the caffeine and placebo treatments over the six measured attempts. A significant difference (treatment×throw) was observed (P=0.030, partial eta-squared = 0.259), indicating that the caffeine treatment produced better performance over the course of the six attempts subsequent to a warm-up. A paired samples t-test (Bonferroni-adjusted for multiple comparisons) revealed that the first attempt in the caffeine treatment (9.62±1.71 m) and in the placebo treatment (9.05±1.69 m) were significantly different (P = 0.050, effect size = 0.996, 95%CI 1.02 to 0.13 m). Repeated-measures analysis of covariance revealed a significant (P=0.016, partial eta-squared = 0.650) interaction effect (treatment×mean reaction time), whereby both at the pre and post time points the mean reaction time on the psychomotor vigilance task was reduced under the caffeine treatment (caffeine: pre 0.306±0.05 s, post 0.316±0.08 s; placebo: pre 0.317±0.06 s, post 0.323±0.06 s). Based on these results, we suggest that caffeine gum can be beneficial for both performance and alertness if used by shot put athletes during early morning sessions.

Validation and Reliability of a Novel Test of Upper Body Isometric Strength

Abstract The purpose of the present investigation was to examine the association of a novel test of upper body isometric strength against a 1RM bench press measurement. Forty college age adults (n = 20 female, n = 20 male; age 22.8 ± 2.8 years; body height 171.6 ± 10.8 cm; body mass 73.5 ± 16.3 kg; body fat 23.1 ± 5.4%) volunteered for the present investigation. The participants reported to the lab on three occasions. The first visit included anthropometric measurements and familiarization with both the upper body isometric test and bench press exercise. The final visits were conducted in a randomized order, with one being a 1RM assessment on the bench press and the other consisting of three trials of the upper body isometric assessment. For the isometric test, participants were positioned in a “push-up” style position while tethered (stainless steel chain) to a load cell (high frequency) anchored to the ground. The peak isometric force was consistent across all three trials (ICC = 0.98) suggesting good reliability. Multiple regression analysis was completed with the predictors: peak isometric force, gender, against the outcome variable 1RM bench press. The analysis resulted in a significant model (r2 = 0.861, p≤0.001) with all predictor variables attaining significance in the model (p<0.05). Isometric peak strength had the greatest effect on the model (Beta = 5.19, p≤0.001). Results from this study suggest that the described isometric upper body strength assessment is likely a valid and reliable tool to determine strength. Further research is warranted to gather a larger pool of data in regard to this assessment.

The relationship of aerobic capacity, anaerobic peak power and experience to performance in CrossFit exercise

CrossFit is becoming increasingly popular as a method to increase fitness and as a competitive sport in both the Unites States and Europe. However, little research on this mode of exercise has been performed to date. The purpose of the present investigation involving experienced CrossFit athletes and naïve healthy young men was to investigate the relationship of aerobic capacity and anaerobic power to performance in two representative CrossFit workouts: the first workout was 12 minutes in duration, and the second was based on the total time to complete the prescribed exercise. The participants were 32 healthy adult males, who were either naïve to CrossFit exercise or had competed in CrossFit competitions. Linear regression was undertaken to predict performance on the first workout (time) with age, group (naïve or CrossFit athlete), VO2max and anaerobic power, which were all significant predictors (p < 0.05) in the model. The second workout (repetitions), when examined similarly using regression, only resulted in CrossFit experience as a significant predictor (p < 0.05). The results of the study suggest that a history of participation in CrossFit competition is a key component of performance in CrossFit workouts which are representative of those performed in CrossFit, and that, in at least one these workouts, aerobic capacity and anaerobic power are associated with success.

Exercise and academic performance among nursing and kinesiology students at US colleges

Context: Lack of physical activity is a contributor to the obesity epidemic and is speculated to relate to reduced academic performance; however, this link has yet to be examined within the college population. Aims: The purpose of this study in a group of undergraduate students, was to determine if aerobic exercise activity was related to academic performance. Materials and Methods: The participants for this study included 740 students at multiple universities enrolled in nursing and kinesiology studies. The participants completed the Leisure and Physical Activity Questionnaire. Results: Pearsons χ2 analysis revealed differences in grade point average with aerobic activity (χ2 = 44.29, P ≤ 0.001) as well as a trend toward differences in grade point average with weightlifting activity (χ2 = 22.69, P = 0.61). Conclusions: Based on these findings it can be suggested that college students engage in greater aerobic exercise.