Acute Metabolic, Hormonal, and Psychological Responses to Different Endurance Training Protocols

In the last years, mainly 2 high-intensity-training (HIT) protocols became common: First, a Wingate-based all-out protocol and second, a 4x4 min protocol. However, no direct comparison between these protocols exists, and also a comparison with high-volume-training (HVT) is missing. Therefore, the aim of the present study was to compare these 3 endurance training protocols on metabolic, hormonal, and psychological responses. Twelve subjects performed: 1) HVT [130 min at 55% peak power output (PPO)]; 2) 4x4 min at 95% PPO; 3) 4x30 s all-out. Human growth hormone (hGH), testosterone, and cortisol were determined before (pre) and 0, 30, 60, 180 after each intervention. Metabolic stimuli and perturbations were characterized by lactate, blood gas (pH, BE, HCO3 (-), pO(2), PCO2), and spirometric analysis. Furthermore, changes of the person's perceived physical state were determined. The 4x30 s training caused the highest increases in cortisol and hGH, followed by 4 x 4 min and HVT. Testosterone levels were significantly increased by all 3 exercise protocols. Metabolic stress was highest during and after 4x30 s, followed by 4x4 min and HVT. The 4x30 s training was also the most demanding intervention from an athlete's point of view. In conclusion, the results suggest that 4x30 s and 4x4 min promote anabolic processes more than HVT, due to higher increases of hGH, testosterone, and the T/C ratio. It can be speculated that the acute hormonal increase and the metabolic perturbations might play a positive role in optimizing training adaptation and in eliciting health benefits as it has been shown by previous long term training studies using similar exercise protocols

High-resolution γ-ray spectroscopy: A versatile tool for nuclear β-decay studies at TRIUMF-ISAC

High-resolution γ-ray spectroscopy is essential to fully exploit the unique, high-quality beams available at the next generation of radioactive ion beam facilities such as the TRIUMF isotope separator and accelerator (ISAC). The 8π spectrometer, which consists of 20 Compton-suppressed HPGe detectors, has recently been reconfigured for a vigorous research programme in weak interaction and nuclear structure physics. With the addition of a variety of ancillary detectors it has become the world\u27s most powerful device dedicated to β-decay studies. This paper provides a brief overview of the apparatus and highlights from recent experiments. © 2005 IOP Publishing Ltd

Superallowed beta decay studies at TRIUMF -nuclear structure and fundamental symmetries

Precision measurement of the β-decay half-life, Q-value, and branching ratio between nuclear analog states of Jπ = 0+ and T = 1 can provide critical and fundamental tests of the Standard Model\u27s description of electroweak interactions. A program has been initiated at TRIUMF-ISAC to measure the ft values of these superallowed beta transitions. Two Tz = 0, A \u3e 60 cases, 74Rb and 62Ga, are presented. These are particularly relevant because they can provide critical tests of the calculated nuclear structure and isospin-symmetry breaking corrections that are predicted to be larger for heavier nuclei, and because they demonstrate the advance in the experimental precision on ft at TRIUMF-ISAC from 0.26% for 74Rb in 2002 to 0.05% for 62Ga in 2006. The high precision world data on experimental ft and corrected Ft values are discussed and shown to be consistent with CVC at the 10-4 level, yielding an average Ft = 3073.70(74) s. This Ft leads to Vud = 0.9737(4) for the up-down element of the Standard Model\u27s CKM matrix. With this value and the Particle Data Group\u27s 2006 values for Vus and V ub, the unitarity condition for the CKM matrix is met. Additional measurements and calculations are needed, however, to reduce the uncertainties in that evaluation, That objective is the focus of the continuing program on superallowed-beta decay at TRIUMF-ISAC