According to a study published in Sports Medicine and Health Science, taking antioxidants like vitamins C and E can enhance health protection during exercise-induced hemolysis. The study revealed that these supplements can increase the count of red blood cells and hemoglobin content. They also improve white blood cell and platelet alterations and the inflammatory profile.
The study aimed to determine whether the effects of eight weeks of supplementation with vitamins C and E during high-intensity interval training (HIIT) caused changes in the lipid profile or hematological variables. The study involved 106 adolescent males who were randomized into 5 age-matched groups, which included no exercise and a placebo; HIIT and placebo; HIIT and vitamin C at a dosage of 1000 mg/day; HIIT and vitamin E at a dosage of 400 IU/day; and combined HIIT and vitamin C and E at the respective strengths.
They had morning and evening sessions of 90 minutes with a 15-minute warm-up and a 15-minute cooldown.
Within the 60-minute HIIT workout, participants went through four phases, each lasting 15 minutes and consisting of three sets, each lasting 4 minutes. All participants completed three full-out HIIT sets. Each HIIT set included a 2-minute intense sprint workout, followed by 1 minute of active recovery, and finally, 1 minute of complete rest.
The researchers evaluated the lipid profile parameters, hematological variables, endurance capacity, and vertical jump. All 4 intervention groups found significant decreases in body weight, fat percentage, total cholesterol, triglyceride, and total cholesterol/high-density lipoprotein-cholesterol (HDL-C). At the same time, there were significant increases in high-density lipoprotein-cholesterol, maximal oxygen consumption, and vertical jump.
The HIIT-only group showed significant decreases in white blood cell count, red blood cell count, hemoglobin percentage, and hematocrit values, with significantly increased platelet count and platelet-to-leukocyte ratio. Combining the supplements resulted in increased fat oxidation and improved lipid profile, including increased HDL-C and decreased atherogenic index. These changes have been linked to a lower risk of cardiovascular disease.
Investigators also found that the vitamins significantly impacted leg strength. However, there was no correlation between the use of vitamin supplements and the improvement in maximal oxygen consumption. It’s important to note that the study had some limitations, such as the small sample size, which means that the results may not represent a larger population. Additionally, the study only included male participants, which restricts its generalizability to the female population.
The study focused solely on HIIT sprint training without varying the intensity, so it doesn’t indicate a wide HIIT effect in terms of intensity, as per the authors. According to the investigators, it also didn’t involve any energy expenditure calculations.
The researchers suggest that future studies should have larger sample sizes that include both men and women and varying training intensities. However, despite these limitations, the investigators believe the findings could be helpful in designing exercise training protocols for athletes.
In short, there was a measurable improvement in all groups that engaged in HIIT training, but an even greater improvement in those that supplemented with one or both of the antioxidants.