High-intensity interval training improves acute plasma volume responses to exercise that is age dependent
Question
Does a 6-week high-intensity interval training program alter plasma volume responses to acute exercise and related age or blood-pressure associations in sedentary adults?
Summary
A six-week supervised cycling sprint program in sedentary adults lowered blood pressure and reduced acute exercise-related plasma volume losses, with age-related plasma volume effects present before but not after training.
Methodology
- Sedentary healthy university staff.
- 30 participants.
- Cycle ergometer.
- Work intervals: 6 s maximal sprint.
- Recovery: 2 min passive recovery.
- Intensity: Maximal sprint against individualized resistance.
- Approximately 15 min.
- 3 sessions/week.
- 6 weeks.
- Single-group pre-post intervention
- Plasma volume response, and Blood pressure were tracked.
Outcomes
Plasma volume
Acute exercise-related plasma volume decreases were smaller after HIT.
Warm-up and supramaximal cycling p<0.001.
Blood pressure
Resting systolic and diastolic blood pressure decreased.
SBP 114.5 to 109.1 mmHg; DBP 78.3 to 71.6 mmHg; p<0.001.
VO2max
VO2max did not significantly change.
Insights
- Very low total sprint work can still affect blood pressure and plasma volume responses.
- Maximal sprint protocols need careful screening and are not a casual beginner format.
Limitations
- No control group
- Hydration/osmolality measures not assessed
- Age subgroup analyses need further study
Safety
- No adverse events were reported.
- All participants completed all training sessions and the article states no other difficulties were encountered.
- Screening excluded cardiovascular and chronic disease, smoking, drug consumption, and orthopedic or neurological disease; testing included ECG/heart-rate monitoring.