Leukocyte, lymphocyte and platelet response to dynamic exercise. Duration or intensity effect?

Area of Science:

• Exercise Physiology
• Hematology
• Sports Science

Background:

• Understanding the hematological response to exercise is crucial for assessing physiological adaptation.
• Previous studies have explored changes in blood cell counts during exercise, but the influence of work intensity and duration requires further investigation.

Purpose of the Study:

• To investigate the effects of different exercise intensities and durations on white blood cell (WBC), lymphocyte (L), and platelet (P) counts in trained individuals.
• To compare the hematological responses between maximal intensity exercise and sustained endurance exercise.

Main Methods:

• Sixteen trained subjects performed three exercise protocols: a progressive test to exhaustion, constant maximal work (VO2max), and a 45-min Square-Wave Endurance Exercise Test (SWEET).
• Arterial blood samples were collected at rest and during various exercise stages to measure WBC, L, P, lactate, ACTH, and other parameters.

Main Results:

• Both maximal and endurance exercise protocols led to significant increases in WBC, L, P, and total platelet volume (TPV).
• While VO2max values were similar, exercise duration differed significantly between protocols (A: 25 min, B: 7 min).
• Hematological responses at VO2max were comparable between protocols, with notable increases in WBC, L, P, and ACTH, but minimal changes in red blood cells.

Conclusions:

• Exercise intensity and duration influence hematological parameters, with significant elevations in WBC, L, and P counts observed.
• Sustained endurance exercise elicits similar acute hematological responses to maximal exercise, with ACTH showing a continued rise over time.
• These findings contribute to understanding the physiological adaptations to different exercise stimuli in trained athletes.