Effects of Resistance Training on Substrate Metabolism During the Menstrual Cycle
Effects of Resistance Training on Substrate Metabolism During the Menstrual Cycle
This research project's objective is to investigate substrate metabolism behavior in response
 to the RT during different phases of the menstrual cycle.
Based on the literature the investigators hypothesize an increase in fat oxidation in early
 follicular phase(EFP) and late follicular phase (LFP) when compared to early luteal phase
 (ELP) and late luteal phase (LLP). Given the lack of research in exercise and menstrual cycle
 - especially in resistance training - results are uncertain unless the investigators base
 their hypotheses only on the general physiological effects of sex hormones (without
 exercise). In this case, the investigators expect to see a reduced carbohydrate utilization
 and an increased utilization of fats in EFP and LFP. In addition, the intervention is focused
 on muscular endurance and, therefore, it is expected to see a higher reliance on aerobic
 pathways. It is expected that the effects of the intervention will be added to the effects of
 estrogens, with increasing fat oxidation when estrogen levels are higher. Lastly, a
 comparison of fat oxidation levels obtained on each sub-phase would reveal if there are
 differences in the magnitude of the effect of distinct concentrations of estrogen and
 progesterone.
Inclusion Criteria:

 -  Females with BMI-18.5-34.99 and between 18-45 years, with normal menstrual cycle
 defined as 28-30 days cycles +-3 days.

 -  Including higher BMI participants might alter the results as increased body fat has
 been linked to changes in different hormonal levels (not only sex hormones) and that
 might influence substrate utilization.

 -  Sedentary .or physically active for 2 days a week or less.

 Exclusion Criteria:

 -  • Musculoskeletal injuries,

 -  cardio-respiratory conditions,

 -  metabolic conditions,

 -  irregular menstrual cycle,

 -  menstrual dysfunction or unusual sex hormone levels,

 -  on contraceptives,

 -  on medication that alter hormonal or cardio-respiratory responses,

 -  pre-menopausal symptoms,

 -  on moderate to high-intensity exercise regime more than 2d/week.

 -  All these exclusion criteria are chosen because any one of the listed criteria
 above can alter the responses and/or affect the safety of the subject during
 their participation in the study.