Michelle A Blanchard

Publications (2)5.73 Total impact

• Article: Acute high-intensity interval training improves Tvent and peak power output in highly trained males.

  Paul B Laursen, Michelle A Blanchard, David G Jenkins
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  ABSTRACT: This study examined the effects of four high-intensity interval-training (HIT) sessions performed over 2 weeks on peak volume of oxygen uptake (VO2peak), the first and second ventilatory thresholds (VT1, VT2) and peak power output (PPO) in highly trained cyclists. Fourteen highly trained male cyclists (VO2peak = 67.5 +/- 3.7 ml.kg-1.min-1) performed a ramped cycle test to determine VO2peak, VT1, VT2, and PPO. Subjects were divided equally into a HIT group and a control group. The HIT group performed four HIT sessions (20 x 60 s at PPO, 120 s recovery); the VO2peak test was repeated < 1 wk after the HIT program. Control subjects maintained their regular training program and were reassessed under the same timeline. There was no change in VO2peak for either group; however, the HIT group showed a significantly greater increase in VT1 (+22% vs. -3%), VT2 (+15% vs. -1%), and PPO (+4.3 vs. -.4%) compared to controls (all P < .05). This study has demonstrated that HIT can improve VT1, VT2, and PPO, following only four HIT sessions in already highly trained cyclists.
  Canadian journal of applied physiology = Revue canadienne de physiologie appliquée 09/2002; 27(4):336-48. · 1.30 Impact Factor
• Article: The influence of diet and exercise on muscle and plasma glutamine concentrations

  MICHELLE A. BLANCHARD, GREGORY JORDAN, BENJAMIN DESBROW, LAUREL T. MACKINNON, DAVID G. JENKINS
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  ABSTRACT: BLANCHARD, M. A., G. JORDAN, B. DESBROW, L. T. MacKINNON, and D. G. JENKINS. The influence of diet and exercise on muscle and plasma glutamine concentrations. Med. Sci. Sports Exerc., Vol. 33, No. 1, 2001, pp. 69-74. Purpose: This study examined the relationship between muscle glutamine, muscle glycogen, and plasma glutamine concentrations over 3 d of high-intensity exercise during which dietary carbohydrate (CHO) intake varied. Methods: Five endurance-trained men completed two exercise trials in randomized order, over a 14-d period. Each trial required subjects to perform 50 min of high-intensity continuous and interval exercise on three consecutive days while consuming a diet that provided 45% of the energy as CHO or a diet in which CHO provided 70% of the total energy. Four days of inactivity and consumption of a 55% CHO diet separated the two randomized trials. Menus and food were provided for the subjects and all food and drink consumed were weighed and recorded for later analysis. Before exercise on the first day of each trial, at the start of exercise on day 3 and on completion of exercise on day 3, muscle was biopsied from the vastus lateralis for the analysis of glutamine and glycogen concentrations. Venous blood was sampled before and twice after exercise on each day for the analysis of plasma glutamine and cortisol concentrations. Results: Mean plasma glutamine concentration was significantly higher during the 70% CHO exercise trial when compared with the 45% CHO trial (P < 0.05). Glycogen decreased by the same magnitude during both trials and there was no relationship between changes in plasma glutamine and changes in muscle glycogen concentration. Muscle glutamine concentration did not change in either trial. Conclusions: These data suggest that the influence of carbohydrate intake upon the concentration of plasma glutamine is not mediated through the concentration of intramuscular glycogen.
  Medicine &amp Science in Sports &amp Exercise 12/2000; 33(1):69-74. · 4.43 Impact Factor