Latest Clinical Research Published by ACSM

LOW MUSCLE FITNESS IS ASSOCIATED WITH METABOLIC RISK IN YOUTH

In the July 2009 issue of Medicine & Science in Sports & Exercise_®, researchers examined the independent associations of muscle fitness and cardiorespiratory fitness with clustered metabolic risk in youth. The authors studied a cohort of 2818 9- to 15-yr-old youth from throughout Norway. Muscular strength was assessed by measuring explosive, isometric, and endurance strength. Cardiorespiratory fitness was measured directly using peak oxygen uptake during a cycle ergometry test. A composite risk factor score was determined using systolic blood pressure, triglyceride, high-density lipoprotein cholesterol, insulin resistance, and waist circumference. Findings of the study revealed a negative association between muscle fitness and clustered metabolic risk, which was independent of cardiorespiratory fitness. Similarly, an inverse association was demonstrated between cardiorespiratory fitness and clustered metabolic risk independent of muscle fitness. The poorest metabolic risk profile was observed among the overweight children and adolescents with low muscle fitness. While both muscle and cardiorespiratory fitness conferred protective effects upon metabolic risk, cardiorespiratory fitness still appears to be more important in predicting metabolic risk. Important to note is the fact that increased muscular fitness seems to confer additional benefits beyond those with cardiorespiratory fitness alone. Bottom line: Promotion of both cardiorespiratory and muscular fitness can have a protective effect upon metabolic risk factors in children and adolescents. For those averse to cardiovascular training, strength training offers another viable option in reducing risk.

THE RELATIVE EFFECTS OF WEIGHT LOSS AND STRENGTH TRAINING UPON BALANCE RECOVERY

Researchers in the July 2009 issue of Medicine & Science in Sports & Exercise_® investigated the relative effects of weight loss and strength training upon balance recovery. The goal was to assist in the development of appropriate interventions to maximize balance in obese individuals because of their increased risk of falls and balance issues. Through the use of an ankle strategy, nine obese male subjects were released from a forward lean and attempted to recover balance. Lean angle was increased until the subjects used either a step or hip flexion to recover balance. The maximum lean angle was used as the measure of balance recovery capability. Numerous simulations were done to determine the effects of weight and strength upon maximum lean angle. Maximum lean angle increased with both strength training and weight loss. Comparing the percent changes in weight and strength required to achieve a specific amount of maximum lean angle revealed differences in efficacy between the two interventions. The study observed that a smaller percent change in weight was required than increase in strength for a targeted improvement in balance recovery. Bottom line: While both interventions reap positive effects, a targeted improvement in balance recovery can be achieved with a smaller amount of weight loss compared with an increase in strength. Planning individual goals in balance recovery should take this into account.