None listed
Conditions
Brief summary
In our recent meta-analyses, exercise has been shown to induce changes in serum zinc levels. However, the quantified results are confounded by multiple study limitations, for example failure to adjust for exercise-induced changes in blood volume. Further, in a previous trial, we observed a significant relationship between habitual physical activity level and zinc transporter gene expression. This suggests that cellular zinc homeostasis may be affected by exercise level, possibly due to exercise adaptations. Therefore, the principal study question is: What is the effect of a maximal cycling exercise bout on markers of zinc homeostasis in healthy men and women? Healthy men (n = 60) and women (n = 60), aged 18-30, will be recruited. Recruited participants will be randomised into an exercise session (n = 30 men, 30 women) or a resting session (n = 30 men, 30 women). Pre-screening questionnaire and a measurement of hemoglobin will be used to determine eligibility for participation. Height, weight, body composition (by bioelectrical impedance analysis) and habitual physical activity level will be collected. Dietary intake will be evaluated with a 3-day food record. 24-h urine collection will be taken on the exercise/resting day to measure urinary zinc excretion. The exercise session will involve a continuous progressive protocol to maximal exercise capacity on a stationary bicycle. Oxygen consumption levels will be measured during the test to obtain level of maximal oxygen consumption (VO2max). Heart rate and rate of perceived exertion will be measured during the test. Blood samples will be collected before exercise, immediately after exercise and at 3 time points during exercise recovery. In the resting session, participants will be sedentary for the blood collection time course. Blood samples will be measured for zinc outcome, gene expressions, haematocrit, sex hormones, inflammatory markers.
Interventions
Participants will complete both the exercise and resting session. The order of the two sessions will be randomised. The washout period will be between 3 to 5 weeks.
The exercise intervention session will be a continuous progressive protocol to maximal exercise capacity on a cycle ergometer; the typical duration of the exercise session will be 8-12 minutes depending on individual physical fitness. Initially, participants will complete a 3 min warm up period with no resistance. The exercise sess
Participants will complete both the exercise and resting session. The order of the two sessions will be randomised. The washout period will be between 3 to 5 weeks. The exercise intervention session will be a continuous progressive protocol to maximal exercise capacity on a cycle ergometer; the typical duration of the exercise session will be 8-12 minutes depending on individual physical fitness. Initially, participants will complete a 3 min warm up period with no resistance. The exercise session starts at a resistance of 100 W (or 75 W for smaller individuals); the resistance will increase by 50 W every 2.5 min until heart rate reach 160 bpm, then the resistance will increase by 25 W every 2.5 min until maximal exercise capacity. Measures, such as blood, will be taken during the exercise and recovery (up to 2 hours after exercise).
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Primary purpose
Prevention
Eligibility
Sex/Gender
All
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy men (n = 30) and women (n = 30), aged 18-30, will be recruited for the study.
Exclusion criteria
Haemoglobin will be measured to exclude volunteers with anaemia. Exclusion criteria include: anaemia, habitual smokers, women who may be pregnant or breastfeeding, women who have amenorrhea or oligomenorrhea, those with a diagnosis of major illness, the use of prescription medication including contraceptive agents and medical contraindication to maximal exercise testing.
Outcome results
None listed