David W. Bacharach

Physiological characteristics and performance of top U.S. biathletes.

Success in biathlon involves skiing fast and shooting accurately. The purpose of this study was to determine whether physiological laboratory test results relate to success in biathlon. Tests included treadmill run and double-pole lactate profile and VO2peak tests, and a double-pole peak power test (UBP). 1993 National Points Rank (NR), racing ski time (ST), and shooting percentage (SP) from 1993 World Team Trials and laboratory test results (1993; N = 11 males, 10 females) were examined. Of athletes tested, six males and six females were top 10 U.S. ranked. Significance was identified between NR and ST (males, r = -0.88; females, r = -0.91). NR and SP were related for females (r = 0.75). Maximum run time during the VO2peak test was the only parameter related to NR (r = 0.72) or ST (r = -0.80) for males. Significance was identified for an uphill 1 km on snow double-pole time trial to NR (r = -0.84) and SP (r = -0.79) (subgroup; N = 8 males). For females, NR was related to running VO2peak (r = 0.81) and UBP (r = 0.95). Double-pole and running VO2peak were related to SP for women. This study suggests that SP is more important to NR for females than for males, and gender-specific tests might better predict success in elite biathlon skiers.

Responses to training in cross-country skiers

PURPOSE This study evaluated whether cross-country skiers who did not respond positively to a training program consisting of high volume and low intensity would improve if high-intensity training volume was doubled during a subsequent training year. METHODS During the first year of the study, cross-country skiers (N = 14) were evaluated for VO2max, VO2threshold, lactate response, max arm power, and competitive results after a standard training program. During the second year, the athletes were divided into a control group (athletes who had responded well to the training) and a treatment group (athletes who had responded poorly to the training). The control group (N = 7) repeated the previous years training program. The treatment group (N = 7) was given a modified training program which increased high-intensity training time as a percentage of total training from < 17% to > 35% and decreased low-intensity training volume 22%. RESULTS The treatment group, using the high-intensity training program, demonstrated significantly improved VO2max, VO2threshold, max arm power, and competitive results (P < 0.05). CONCLUSIONS Increased volume of high-intensity training may improve competitive results in cross-country skiers who fail to respond to increased volume of low-intensity training.

Response of patients with coronary artery disease stratified by ejection fraction following short-term training

The purpose of this study was to investigate the response of patients with ischemic heart disease and varied left ventricular function following 6 weeks of exercise training. We studied the oxygen consumption (VO2), and central hemodynamic and metabolic responses of 14 patients with coronary artery disease (CAD) stratified by left ventricular ejection fraction (EF). There were two groups of patients: normal EF (NEF), EF = 64 +/- 9.9 (mean +/- S.E.M.); n = 7, and diminished EF (DEF), EF = 36 +/- 11.6; n = 7. The patients ranged in age from 42 to 72 years (54.9 +/- 2.2), and were evaluated prior to and then following training. Measures of VO2, cardiac output (Qt) stroke volume (SV), heart rate (HR), exercise duration (XTIME) and intensity (XI), as well as plasma lactate (LA), and the catecholamines epinephrine (E) and norepinephrine (NE) were obtained in response to maximal cycle ergometry. Subjects trained three times per week, 30 min per session, at an intensity equal to 70% of their peak oxygen consumption. Repeated measures analysis of variance (ANOVA) revealed no interaction between groups suggesting a similar training response. Significant post-training changes (P < 0.05) were observed in peak VO2 (VO2peak) NEF, 11.8% increase, (16.0 +/- 1.3 to 17.9 +/- 1.1 ml/kg/min) and DEF, 9.3% increase (15.1 +/- 1.6 to 16.5 +/- 1.2 ml/kg/min); submaximal HR, 4% decrease in the NEF (95.57 +/- 4.58 to 92 +/- 4.43 beats/min) and a 6% decrease in the DEF (107.29 +/- 7.44 to 101.43 +/- 6.77 beats/min); XTIME NEF, 11.2% increase (7.8 +/- 0.57 to 8.67 +/- 0.61 min) and DEF, 16.6% increase (7.3 +/- 0.91 to 8.51 +/- 0.69 min); and XI NEF, 19.2% increase (104.3 +/- 11.3 to 124.3 +/- 12.9 W) DEF, 21.2% increase (94.3 +/- 18.5 to 114.3 +/- 16.9 W), and a 15% decrease in resting NE (350 +/- 26 to 296.9 +/- 19 pg/ml). There were no changes in Qt, SV, LA, E, peak NE or peak HR for either group. These findings suggest short-term endurance training at 70% VO2peak provide the necessary stimulus for individuals with CAD and NEF or DEF to display an improvement in XI, XTIME, and VO2peak. The lack of a significant enhancement in Qt with short-term training may indicate that the mechanism by which both study groups were able to attain significantly higher levels of VO2peak may have been attributable to peripheral mechanisms rather than any alterations in Qt, a central mechanism.

TESTING GAME BASED PERFORMANCE IN TEAM-HANDBALL.

Abstract Wagner, H, Orwat, M, Hinz, M, Pfusterschmied, J, Bacharach, DW, von Duvillard, SP, and Müller, E. Testing game-based performance in team-handball. J Strength Cond Res 30(10): 2794–2801, 2016—Team-handball is a fast paced game of defensive and offensive action that includes specific movements of jumping, passing, throwing, checking, and screening. To date and to the best of our knowledge, a game-based performance test (GBPT) for team-handball does not exist. Therefore, the aim of this study was to develop and validate such a test. Seventeen experienced team-handball players performed 2 GBPTs separated by 7 days between each test, an incremental treadmill running test, and a team-handball test game (TG) (2 × 20 minutes). Peak oxygen uptake (V[Combining Dot Above]O2peak), blood lactate concentration (BLC), heart rate (HR), sprinting time, time of offensive and defensive actions as well as running intensities, ball velocity, and jump height were measured in the game-based test. Reliability of the tests was calculated using an intraclass correlation coefficient (ICC). Additionally, we measured V[Combining Dot Above]O2peak in the incremental treadmill running test and BLC, HR, and running intensities in the team-handball TG to determine the validity of the GBPT. For the test-retest reliability, we found an ICC >0.70 for the peak BLC and HR, mean offense and defense time, as well as ball velocity that yielded an ICC >0.90 for the V[Combining Dot Above]O2peak in the GBPT. Percent walking and standing constituted 73% of total time. Moderate (18%) and high (9%) intensity running in the GBPT was similar to the team-handball TG. Our results indicated that the GBPT is a valid and reliable test to analyze team-handball performance (physiological and biomechanical variables) under conditions similar to competition.

Enhancement of functional power in patients with coronary artery disease by circuit interval training

The purpose of this study was to investigate the effect of a 12‐week circuit interval training (CIT) program on several indices of functional power in coronary artery disease (CAD) patients following from the exercise regimen. Twenty‐two patients with documented CAD served as subjects. After training, peak oxygen consumption (ml kg−1 min−1) and maximal MET level achieved in these patients increased significantly (p ≤ 0.05). Several hemodynamic variables and electrocardiographic data were studied to try to assess whether functional power was enhanced predominantly by central or peripheral hemodynamic and metabolic events. Maximal ST‐segment depression did not decrease significantly, and peak heart rate (HR), systolic blood pressure, rate‐pressure product, and the HR at the time of ST‐segment depression did not increase significantly. These data imply that the change in functional power observed was primarily the result of adaptation in the periphery.