Benefits on Hematological and Biochemical Parameters of a High-Intensity Interval Training Program for a Half-Marathon in Recreational Middle-Aged Women Runners
Question
Do HIIT-oriented and moderate continuous half-marathon training programs produce different hematological and biochemical responses in recreational middle-aged women runners?
Summary
Twenty recreational middle-aged women runners trained for a half-marathon with either a lower-volume HIIT-oriented program or a moderate continuous running program. Both groups completed the race; the HIIT program used less time and distance and showed some smaller post-race muscle-damage and inflammatory marker changes than the moderate program.
Methodology
- Twenty healthy female master recreational runners
- 20 participants.
- Running intervals, hills, bodyweight circuit, sprints, and long runs.
- Work intervals: Varied: 200 m, 400 m, hills, circuit stations, 50 m sprints.
- Recovery: Varied.
- Intensity: High-intensity elements; exact target not reported.
- Total 33 h 26 min across 12 weeks.
- 3 sessions/week.
- 12 weeks.
- Randomized training comparison from a larger trial
- Inflammation, Muscle damage, Lipids, and Electrolytes were tracked.
Outcomes
Training load
HIIT used less time and distance than MICT.
33 h 26 min vs 40 h 30 min; 301 km vs 383 km.
CK
Post-race CK rose in both groups but less in HIIT.
HIIT +63% vs MICT +153%; p=0.043.
CRP
Post-race CRP rose in both groups but less in HIIT.
Between-group post-race difference p=0.039.
Safety markers
No hyponatremia or liver-injury signal was reported, but post-race oxidative and inflammatory stress increased.
Insights
- Lower-volume interval-oriented training may be feasible for experienced half-marathon runners.
- Race preparation and race completion still produce measurable recovery stress.
- Consumer programming should include recovery, hydration, and runner-readiness constraints.
Limitations
- Small sample.
- Women-only trained runner population.
- Nutritional data were limited.
- Premenopausal status variability may confound biochemical markers.
- Adverse-event and adherence reporting were limited.
Safety
- Adverse events and dropouts were not explicitly reported.
- Participants were screened as healthy, nonsmoking, premenopausal, medication-free, and injury-free recreational runners.
- All participants appear in final sampling and race analyses; the race increased muscle-damage, inflammatory, and oxidative-stress markers.
- The authors reported no exercise-associated hyponatremia and no liver-injury marker pattern.