Edward J. Ryan

Caffeine Gum and Cycling Performance: A Timing Study

Abstract Ryan, EJ, Kim, C-H, Fickes, EJ, Williamson, M, Muller, MD, Barkley, JE, Gunstad, J, and Glickman, EL. Caffeine gum and cycling performance: A timing study. J Strength Cond Res 27(1): 259–264, 2013—The purpose of this study was to determine the most efficacious time to administer caffeine (CAF) in chewing gum to enhance cycling performance. Eight male cyclists participated in 5 separate laboratory sessions. During the first visit, the subjects underwent a graded exercise test to determine maximal oxygen consumption (V[Combining Dot Above]O2max). During the next 4 visits, 3 pieces of chewing gum were administered at 3 time points (120-minute precycling, 60-minute precycling, and 5-minute precycling). In 3 of the 4 visits, at 1 of the time points mentioned previously, 300 mg of CAF was administered. During the fourth visit, placebo gum was administered at all 3 time points. The experimental trials were defined as follows: trial A (–120), trial B (–60), trial C (–5), and trial D (Placebo). After baseline measurements, time allotted for gum administration, and a standard warm-up, the participants cycled at 75% V[Combining Dot Above]O2max for 15 minutes then completed a 7-kJ·kg−1 cycling time trial. Data were analyzed using a repeated measures analysis of variance. Cycling performance was improved in trial C (–5), but not in trial A (–120) or trial B (–60), relative to trial D (Placebo). CAF administered in chewing gum enhanced cycling performance when administered immediately prior, but not when administered 1 or 2 hours before cycling.

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.

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.

Test–retest reliability of Purdue Pegboard performance in thermoneutral and cold ambient conditions

In the cold, Purdue Pegboard (PP) performance declines. The purpose of this study was to determine if this cold-induced impairment is consistent across days (i.e. test–retest reliability) in 5°C. In thermoneutral air (25°C), 14 men were familiarised to the dominant hand (PPa) and bimanual (PPb) PP tasks. They then experienced two 90-min cold exposures (Day 1, Day 2) while wearing ∼1 clo. Bare hands were maintained throughout. Performance on both tasks showed high reliability from day to day (intraclass correlations >0.700) in both thermoneutral and cold conditions. However for both tasks, room temperature performance did not predict performance in the cold (intraclass correlations <0.450). When screening applicants for manual labour in the cold, one must consider that room temperature dexterity does not correlate with dexterity in the cold. It is recommended that a 60-min period of cold exposure be employed to assess manual dexterity in these workers. Statement of Relevance: This study shows that PP performance in room temperature does not predict performance in the cold but performance in the cold is consistent from day to day. When screening applicants for manual labour in the cold, it is recommended that dexterity tests be conducted in the same ambient conditions.

Catecholamine Levels in Hypoxia-Induced Acute Mountain Sickness

UNLABELLED Enhanced sympathoadrenal activity has been implicated in the pathogenesis of acute mountain sickness (AMS). This study was designed to examine the time course of circulating catecholamines in individuals with and without AMS. METHODS Subjects were low-altitude residents (10 men, 8 women) who had not been exposed to altitude within the previous 2 mo. They breathed 12% O2 (hypoxia equivalent to 4600 m altitude) for 8 h while seated at rest. AMS was evaluated using Lake Louise scores (LLS) at 0, 1, 3, 5, and 7 h of exposure using a threshold of 3 to define AMS. Blood samples were collected to measure arterial blood gases and oxygen saturation as well as arterial and venous epinephrine (A-EPI and V-EPI) and norepinephrine (A-NE and V-NE). RESULTS Eight subjects (44%) developed AMS at some time during the experiment. Blood gases showed no significant difference between subjects with or without symptoms (AMS+ and AMS-, respectively). However, AMS+ subjects showed significantly greater concentrations of A-EPI over the 8 h without any between-group difference in V-EPI. Levels of A-NE were significantly higher at baseline and during the first hour of hypoxia in subjects who later developed AMS. V-NE increased significantly over time among all participants with no difference between groups. CONCLUSIONS These findings suggest a possible physiological marker for individuals who may be relatively susceptible to AMS and provide additional insight into the sympathoadrenal response to acute hypoxia.

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.

Hemodynamic and thermoregulatory responses to lower body water immersion.

INTRODUCTION Lower body water immersion (LBWI) is experienced in the marine industry but the physiological responses to LBWI are unclear. The purpose of the current experiment was to test the effects of water temperature and immersion duration on rectal temperature, heart rate, stroke volume, blood pressure, metabolic rate, and thermal sensation in healthy subjects. METHODS Nine young men underwent two 60-min trials of seated LBWI to the iliac crest in a counterbalanced fashion. On one occasion, the water was 35 degrees C (LBWI-Neutral) and on the other it was 13 degrees C (LBWI-Cold); the upper body remained thermoneutral and dry throughout. RESULTS As expected, exposure to cold water reduced mean skin temperature and individuals reported cold thermal sensation. Mean arterial pressure was significantly higher at 60 min of LBWI-Cold (86 +/- 7 mmHg) compared to LBWI-Neutral (76 +/- 5 mmHg) while heart rate tended to be lower. The change in rectal temperature from baseline to 30 min of LBWI-Cold (delta = -0.01 +/- 0.21degrees C) was significantly smaller than the change in T(re) from 30 to 60 min of LBWI-Cold (delta = -0.46 +/- 0.16 degrees C). Despite this accelerated drop in core temperature during minutes 30-60, metabolic rate did not increase significantly. CONCLUSION LBWI-Cold reduces core temperature and increases arterial blood pressure via an increase in total peripheral resistance. This experimental model may help scientists better understand the body during cold stress. Further, people who are occupationally exposed to cold water (when the torso, hands, and arms remain thermoneutral) may be at increased risk for hypothermia.

Cognitive function during lower body water immersion and post-immersion afterdrop.

INTRODUCTION The physiological effects of immersion hypothermia and afterdrop are well-characterized, but the psychological effects are less clear. The purpose of this study was to quantify changes in cognitive function during and after lower body water immersion. METHODS On separate mornings, nine young healthy men participated in both neutral (35 +/- 1 degree C) and cold (13 +/- 1 degree C) water immersion. Subjects rested in neutral air for 30 min followed by 60 min water immersion to the iliac crest and 15 min of recovery in neutral air. Rectal temperature and mean skin temperature were continuously monitored. Metabolic rate, the Stroop Color Word Test (SCWT), and the Profile of Mood State (POMS) were quantified at predetermined intervals. RESULTS During immersion in cold water, rectal temperature was reduced, but SCWT and POMS scores were unchanged relative to baseline. Despite the reduced rectal temperature, little to no shivering was observed during immersion and metabolic rate did not change. During recovery from cold immersion, rectal temperature was further reduced by approximately 0.5 degree C, shivering was noted, and metabolic rate increased. Coincident with this acute afterdrop, SCWT Color-Word performance (delta = -4 +/- 8 vs. 7 +/- 6 correct responses) and Interference score (delta = -2 +/- 7 vs. 4 +/- 8) was impaired relative to recovery from neutral immersion (i.e., when core temperature and metabolic rate did not change). CONCLUSION These results suggest that recovery from lower body cold water immersion elicits the afterdrop phenomenon and shivering, which together impair selective attention as measured by the SCWT.

Effect of acute salt ingestion upon core temperature in healthy men

Salt intake may cause conflict for the cardiovascular system as it attempts to simultaneously maintain blood pressure (BP) and temperature homeostasis. Our objective was to determine the effect of a salt and water load vs. a water load upon rectal temperature (Tre) in healthy volunteers. Twenty-two healthy, non-hypertensive Caucasian men enrolled in two trials in which they ingested either salt and body temperature water (SALT), or body temperature water (WATER). BP, Tre, cardiac index, peripheral resistance and urine output were monitored one, 2 and 3 h post-baseline. Changes in the dependent variables were compared between those subjects who were salt sensitive (SS) and those who were salt resistant (SR) at the same time intervals. The percentage change reduction in Tre was greater following SALT compared with WATER at +120 min (−1.1±0.7 vs. −0.6±0.5%, P=0.009) and at +180 min (−1.3±0.8 vs. −0.7±0.6%, P=0.003). The percentage change reduction in Tre was greater in the SR group compared with the SS group at +180 min (−1.6±0.9 vs. −0.9±0.5%, P=0.043). SALT decreased Tre more than WATER. SS individuals maintained temperature homeostasis more effectively than SR individuals following SALT. These results may explain why some individuals are SS while others are SR. If these results are generalizable, it would be possible to account for the role of sodium chloride in the development of SS hypertension.