Effect of diet on performance during recovery from intermittent sprint exercise

Eighteen games players (9 males, 9 females) performed 30 maximum 6‐s sprints on a non‐motorized treadmill. Each sprint was preceded by a 60‐s jog at 40% maximum speed and was followed by a 54‐s walk at 20% maximum speed. Thus, the entire test was of 60‐min duration. The subjects were then randomly assigned to three groups and repeated the 1‐h test 24 h later after consuming either a high, normal or low carbohydrate diet (79 ±3, 47 + 8, 12+1% CHO, respectively). During trial 1, mean power output declined from 653 + 131 to 600+ 158 W during the 30 sprints (P<0.01) and power output was lower during trial 2 than during trial 1 (n = 18, P< 0.01). During trial 2, there were no differences in sprint performance between the dietary groups for the exercise test as a whole (trial 2 mean power lower than trial 1 by 0.2, 0.5 and 5.0% for the high, normal and low CHO groups, respectively; N.S.#CP, but if only the first nine sprints are considered, then the high CHO group performed better than the low CHO group (P<0.05). Blood lactate and glucose concentrations were lower during trial 2 than trial 1 by 4.5, 13.8 and 29.0% (lactate)and 14.9, 11.3 and 35.8% (glucose) for the high, normal and low CHO groups, respectively (both P<0.01). Thus, both the metabolic responses to, and the performance of, maximum intermittent exercise were reduced when the test was repeated after 24 h recovery. In addition, both the performance and the metabolic responses to test 2 were altered by dietary manipulation in the intervening period.

Keywords:

• Recovery
• diet
• lactate
• glucose
• intermittent exercise
• sprinting

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