Scott Doberstein

The talk test as a marker of exercise training intensity.

PURPOSE Correlative data have suggested that the Talk Test (TT) may be a surrogate of the ventilatory threshold (VT). This study examined manipulations of either the VT or exercise protocol to test the hypothesis that the TT and VT are related in a robust way, adequate for exercise prescription. METHODS Healthy young adults participated in 4 independent series of experiments designed to decrease (blood donation) or increase (training) VT, or to systematically vary the exercise intensity above and below VT. These interventions were matched to responses of the TT. RESULTS The changes in the exercise intensity at VT and at the last positive stage of the TT matched each other following both blood donation and training. When exercise intensity was varied above and below VT, the predicted ability to speak was well matched to observations of the TT. Predictive errors biased toward passing the TT when exercise intensity was greater than VT. The time required for the result of TT to become negative when exercise intensity was more than VT, decreased with increasing intensity but averaged more than the 2 minutes that has been used in previous studies. CONCLUSIONS This study confirms the robust relationship between VT and the TT during various interventions and suggests that the TT is suitable for exercise prescription.

The effect of beta-alanine supplementation on power performance during repeated sprint activity.

Sweeney, KM, Wright, GA, Brice, AG, and Doberstein, ST. The effect of β-alanine supplementation on power performance during repeated sprint activity. J Strength Cond Res 24(1): 79-87, 2010-The dipeptide carnosine has been shown to contribute to the buffer capacity of hydrogen ions (H+) during intense exercise. Increasing skeletal muscle carnosine levels through β-alanine (BA) supplementation has been shown to maintain acid-base balance, delay fatigue, and improve exercise performance. We designed this study to examine the effect of 5 weeks of BA supplementation on repeat high-intensity sprint performance. Nineteen, physically active, college men were divided into 2 groups (control [C], n = 10 or BA, n = 9). We performed double-blind placebo-controlled study where subjects ingested 4 g per day during the first week and 6 g per day over the next 4 weeks of a placebo (rice flour) or a BA supplement. Subjects completed 2 sets of 5 5-second sprints with 45-second recovery separated by 2 minutes of active recovery. All tests were conducted on a non-motorized treadmill against a resistance of 15% of the participants body weight. We recorded horizontal power (HP) of the running sprint. Post-exercise capillary blood samples were analyzed for lactate to determine the metabolic demands. There were no significant between-group differences (p > 0.05) in HPpeak or HPmean for the repeat sprint protocol. No significant between-group differences were found for performance decrement (% fatigue) for HPpeak or HPmean. In addition, no significant interactions were observed. Post-exercise blood lactate values were similar pre and post supplementation in both groups. The results of this study clearly indicate that 5 weeks of BA supplementation provides no benefit for repeat sprint performance.

Translation of Exercise Testing to Exercise Prescription Using the Talk Test

Jeans, EA, Foster, C, Porcari, JP, Gibson, M, and Doberstein, S. Translation of exercise testing to exercise prescription using the talk test. J Strength Cond Res 25(3): 590-596, 2011-Traditionally defined in terms of %maximal heart rate (%HRmax) or %maximal metabolic equivalents, the process of exercise prescription is still difficult and individually imprecise. An alternative, and simpler, method is to define exercise intensity in terms of the Talk Test, which may be a surrogate for ventilatory threshold and more consistent with contemporary recommendations for index training intensity in well-trained and athletic individuals. This study was designed to determine how much of a reduction in the absolute exercise intensity from those observed during incremental exercise testing was necessary to allow for comfortable speech during exercise training. Fourteen well-trained (5-7 h·wk−1) individuals performed 2 incremental exercise tests (to evaluate reproducibility) and 3 steady-state training bouts (40 minutes), based on the stage before the last positive (LP) stage of the Talk Test (LP-1), the LP stage, and the equivocal (EQ) stage. The LP-1 and LP runs resulted in %HRmax and rating of perceived exertion (RPE) values within the recommended range for exercise training, the EQ run in an unacceptably high %HRmax and RPE. Most subjects could still speak comfortably during the LP-1 and LP stages, and no subject could speak comfortably during the EQ stage. The HR (r = 0.84), RPE (r = 0.81), and Talk Test (r = 0.71) responses during paired incremental tests were well correlated. The results of this test suggest that the absolute exercise intensity during the LP-1 and LP stages of incremental exercise tests with the Talk Test may produce steady-state exercise responses appropriate for training in well-trained and athletic individuals and that the reproducibility of the Talk Test is satisfactory.

Effects of Beta-Alanine Supplementation on Sprint Endurance

Abstract Jagim, AR, Wright, GA, Brice, AG, and Doberstein, ST. Effects of beta-alanine supplementation on sprint endurance. J Strength Cond Res 27(2): 526–532, 2013—Recent research has shown that beta-alanine (BA) supplementation can increase intramuscular carnosine levels. Carnosine is an intramuscular buffer, and it has been linked to improvements in performance, specifically during bouts of high-intensity exercise that are likely limited by muscle acidosis. Therefore, the purpose of this study was to examine the effect of BA supplementation on sprint endurance at 2 different supramaximal intensities. Twenty-one anaerobically trained (rugby players [n = 4], wrestlers [n = 11], and recreationally strength trained athletes [n = 6]) college-aged men participated in a double-blind, placebo controlled study. The subjects performed an incremental V[Combining Dot Above]O2max test and 2 sprint to exhaustion tests set at 115 and 140% of their V[Combining Dot Above]O2max on a motorized treadmill before (PRE) and after (POST) a 5-week supplementation period. During this time, the subjects ingested either a BA supplement or placebo (PLA) with meals. The subjects ingested 4 g·d−1 of BA or PLA during the first week and 6 g·d−1 the following 4 weeks. Capillary blood samples were taken before and after each sprint to determine blood lactate response to the sprint exercise. No significant group (BA, PLA) × intensity (115%, 140%; p = 0.60), group by time (PRE, POST; p = 0.72), or group × intensity × time (p = 0.74) interactions were observed for time to exhaustion. In addition, similar nonsignificant observations were made for lactate response to the sprints (group × intensity, p = 0.43; group × time, p = 0.33, group × intensity × time, p = 0.56). From the results of this study, it was concluded that beta-alanine supplementation did not have a significant effect on sprint endurance at supramaximal intensities.

The effect of handrail support on oxygen uptake during steady-state treadmill exercise.

RATIONALE Heart rate (HR) and oxygen consumption (VO(2)) are indicators of the intensity of exercise. Handrail support has been shown, during maximal treadmill testing, to blunt HR and VO(2) responses at a particular speed and grade, resulting in an increased treadmill time and overprediction in aerobic capacity. OBJECTIVES This study was designed to determine if handrail support would similarly blunt HR and VO(2) responses during steady-state treadmill exercise at intensities typical of exercise training. METHODS Healthy volunteers (age, 38-60 years; N = 10) performed maximal treadmill exercise to define VO2max (35.4 +/- 6.5 mL kg(-1) min(-1)) and ventilatory threshold (26.4 +/- 5.8 mL kg(-1) min(-1)). They also performed 3 random steady-state exercise bouts including free arm swing, handrail support-resting, and handrail support-gripping (HRS-G). Each test consisted of three 5-minute stages with intensity levels corresponding to 75%, 85%, and 95% of the speed and grade at ventilatory threshold. RESULTS There were significant (P < .05) differences in HR and VO2 at the 75%, 85%, and 95% ventilatory thresholds in HRS-G (108, 114, and 121 beats min and 17.2, 18.0, and 20.6 mL kg min, respectively) versus handrail support-resting (114, 126, and 137 beats min and 19.5, 21.8, and 23.9 mL kg min, respectively) and HRS-G versus free arm swing (120, 130, and 142 beats min and 20.3, 22.8, and 26.1 mL kg min, respectively). Rating of perceived exertion was significantly (P < .05) different between HRS-G (1.8, 2.4, and 3.1) and free arm swing (2.2, 2.9, and 3.6) at all intensities and between HRS-G (2.4 and 3.1, respectively) and handrail support-resting (3 and 3.7, respectively) at the 85% and 95% ventilatory thresholds. CONCLUSION Gripping and, to a lesser degree, resting the hands on the handrails during steady-state treadmill walking will blunt responses during exercise training and may result in less predictable exercise program.

Postfixed Brachial Plexus Radiculopathy Due to Thoracic Disc Herniation in a Collegiate Wrestler: A Case Report

OBJECTIVE To present the unique case of a collegiate wrestler with C7 neurologic symptoms due to T1-T2 disc herniation. BACKGROUND A 23-year-old male collegiate wrestler injured his neck in a wrestling tournament match and experienced pain, weakness, and numbness in his left upper extremity. He completed that match and 1 additional match that day with mild symptoms. Evaluation by a certified athletic trainer 6 days postinjury showed radiculopathy in the C7 distribution of his left upper extremity. He was evaluated further by the team physician, a primary care physician, and a neurosurgeon. DIFFERENTIAL DIAGNOSIS Cervical spine injury, stinger/burner, peripheral nerve injury, spinal cord injury, thoracic outlet syndrome, brachial plexus radiculopathy. TREATMENT The patient initially underwent nonoperative management with ice, heat, massage, electrical stimulation, shortwave diathermy, and nonsteroidal anti-inflammatory drugs without symptom resolution. Cervical spine radiographs were negative for bony pathologic conditions. Magnetic resonance imaging showed evidence of T1-T2 disc herniation. The patient underwent surgery to resolve the symptoms and enable him to participate for the remainder of the wrestling season. UNIQUENESS Whereas brachial plexus radiculopathy commonly is seen in collision sports, a postfixed brachial plexus in which the T2 nerve root has substantial contribution to the innervation of the upper extremity is a rare anatomic variation with which many health care providers are unfamiliar. CONCLUSIONS The injury sustained by the wrestler appeared to be C7 radiculopathy due to a brachial plexus traction injury. However, it ultimately was diagnosed as radiculopathy due to a T1-T2 thoracic intervertebral disc herniation causing impingement of a postfixed brachial plexus and required surgical intervention. Athletic trainers and physicians need to be aware of the anatomic variations of the brachial plexus when evaluating and caring for patients with suspected brachial plexus radiculopathies.

The Effects of Wearing Cold Garments on Energy Expenditure: 1920 Board #181 May 31 2

Introduction: Stimulation of brown adipose tissue (BAT) by cold exposure purportedly upregulates energy expenditure (EE) and has been suggested as a method to reduce adiposity. BAT in humans is located primarily in the upper torso. Manufacturers have developed garments that contain ice packs and are designed to be worn over these areas. Two such products are the Cool Fat Burner and the Cool Gut Buster. The Cool Fat Burner places ice packs against the shoulders and neck, while the Cool Gut Buster is worn around the abdomen. Purpose: This study was designed to evaluate changes in EE when wearing the Cool Fat Burner and the Cool Gut Buster. Methods: Twenty subjects (12 males; 8 females) sat quietly for a total of 90 minutes while heart rate (HR) and VO2 were recorded. Data collection was separated into three 30-minute phases: rest, low-intensity, and high-intensity. Subjects sat quietly during the rest phase, wore both the Cool Fat Burner and the Cool Gut Buster during the low-intensity phase, and wore both garments and drank cold water during the high-intensity phase. Results: Average VO2 increased significantly across all three phases (rest: 295.6 ± 69.1 ml/min; low-intensity: 333.0 ± 83.2 ml/min; high-intensity: 372.8 ± 87.5 ml/min). When VO2 was converted to EE, it was found that 6 additional kcals were burned in the 30-min low-intensity phase compared to rest (50.1 ± 12.6 vs. 44.1 ± 10.5 kcal) and 11.7 additional kcals were burned during the 30-min high-intensity phase compared to rest (55.8 ± 13.2 vs. 44.1 ± 10.5 kcal). Conclusion: Wearing cold garments resulted in a significant increase in EE. However, the magnitude of the increase may not be practically useful as a weight loss tool.

Acute Effects of the Elevation Training Mask on Strength Performance in Recreational Weight lifters

Abstract Jagim, AR, Dominy, TA, Camic, CL, Wright, G, Doberstein, S, Jones, MT, and Oliver, JM. Acute effects of the elevation training mask on strength performance in recreational weightlifters. J Strength Cond Res 32(2): 482–489, 2018—The Elevation Training Mask 2.0 (ETM) is a novel device that purportedly simulates altitude training. The purpose of this study was to investigate the acute effects of the ETM on resistance exercise performance, metabolic stress markers, and ratings of mental fatigue. Twenty male recreational weight lifters completed 2 training sessions of back squat and bench press (6 sets of 10 repetitions at 85% of 5-repetition maximum and seventh set to failure) as well as a maximal effort sprint test (18% body mass) with the mask (ETM) and without the mask (NM). Training evaluation included baseline and postexercise blood lactate and oxygen saturation measures. Performance evaluation included peak and average velocity bar velocity, total volume load, total work, total repetitions completed, and sprint performance. Adverse side effects were reported in 12% (n = 3) of participants, which included feelings of light headedness, anxiety, and discomfort. No differences were found in repetitions or total workload in back squat (p = 0.07) or bench press (p = 0.08) between conditions. A lower peak velocity was identified during the back squat, bench press, and sprint test in the ETM condition (p = 0.04). Blood lactate values were lower after bench press and sprint during the ETM condition (p < 0.001). Significantly lower ratings of alertness and focus for task were found after squat, bench press, and sprint test in the ETM condition compared with the NM condition (p < 0.001). Wearing the ETM during bouts of resistance training did not hinder the ability to achieve desired training volumes during the resistance training session. However, wearing the ETM does seem to attenuate the ability to maintain working velocity during training bouts and negatively influence ratings of alertness and focus for task.