Resting arterial diameter and blood flow changes with resistance training and detraining in healthy young individuals.

CONTEXT: Disruptions to habitual training routines are commonly due to injury or illness and can often lead to detraining adaptations. The implications of such adaptations to the human vasculature in a trained, asymptomatic population are not fully understood.

OBJECTIVE

To determine the extent of local and systemic changes in arterial diameter and blood flow to resistance training and subsequent detraining in young adults.

DESIGN

Randomized controlled clinical trial.

SETTING

University physiology laboratory and fitness suite.

PATIENTS OR OTHER

PARTICIPANTS

Twenty-one healthy volunteers (aged 20.0 ± 2.8 years, 11 men and 10 women).

INTERVENTION(S): Eight-week lower limb resistance training period and subsequent 4-week detraining period.

MAIN OUTCOME MEASURE(S): Quadriceps and hamstrings concentric torque (strength), resting heart rate, arterial diameter, and blood flow velocity in the superficial femoral and carotid arteries were measured at 0, 8, 10, and 12 weeks.

RESULTS

Resistance training increased quadriceps and hamstring strength (32% and 35%, respectively, P < .001), whereas strength decreased during detraining (24% and 27%, respectively, P < .05). Resting heart rate decreased after resistance training (16%, P < .01) and increased during detraining (19%, P < .001). Additionally, resistance training significantly increased superficial femoral and carotid resting arterial diameters (27% and 13%, respectively, P < .001) and mean blood flow (53% and 55%, respectively, P < .001). Detraining resulted in a significant decrease in superficial femoral and carotid resting diameter (46% and 10%, respectively, P < .001) and mean blood flow (61% and 38%, respectively, P < .05).

CONCLUSIONS

Resistance training initiated both local and systemic changes to arterial diameter and blood flow; these changes appeared to reverse after detraining. The local changes in response to detraining showed a worsening (beyond pretraining values) of the vascular dimensional and blood flow characteristics.