Dietary protein intake is associated with maximal and explosive strength of the leg flexors in young and older blue collar workers

Abstract

The aim of this study was to investigate the association between dietary PRO intake and maximal and rapid strength of the leg flexors in blue collar (BC) working men. Twenty-four young (age=23.2±2.1 yrs), and nineteen older aged (age=52.8±5.2 yrs) men employed in BC occupations completed a three day dietary record and isometric strength testing of the leg flexors. Food logs were analyzed for total protein (TPRO) and essential amino acid (EAA) intake. Rapid and maximal strength capacities were examined from the rate of torque development at 50ms (RTD50) and peak torque (PT) of the torque-time curves, respectively. Pearson correlations and partial correlations were used to examine the relationships between TPRO and EAA intake on strength variables. PT was positively correlated to TPRO and EAA intake in the young (r=0.439 and 0.431;P<0.05) and older aged (r=0.636 and 0.605; P<0.01) men and RTD50 was correlated to TPRO and EAA intake in the young (r=0.512 and 0.310; P=0.01) and older aged (r=0.662 and 0.665; P<0.01) men, respectively. There were no relationships (P>0.05) between TPRO and strength variables when controlling for EAA intake. TPRO intake explained 20–44% of the variance in rapid and maximal strength for both age groups. EAA intake was largely responsible for the positive relationship between PRO intake and strength. Across young and older aged blue collar working male populations, protein consumption was associated with both maximal and explosive strength capacities of the leg flexors muscle group.

Age threshold for recommending higher protein intake to prevent age-related muscle weakness: A cross-sectional study in Japan

“…Mulla et al reported no significant association between protein intake at age 36 and 43 years and grip strength at age 53 years [39]. Thompson et al reported that protein intake had smaller effect on muscle strength of the leg flexors in middle-aged adults than in older adults [40]. Nevertheless, evidence that indicates the age threshold at which a higher protein intake is required to prevent the age-related loss of muscle strength is scarce.…”

Effect of intestinal parasites on anaerobic performance and muscle strength in athletes

“…Due to reasons such as malnutrition or malabsorption, energy restrictions limit the performance of high-intensity exercise (36). In a previous study, the muscle strength of the leg flexor muscles was shown to be related to the amount of protein taken (37). In the present study, when the isokinetic muscle strength values of the groups were compared, the explosive muscle strength of the dominant leg knee extensors was better in the control group.…”

The Influence of Habitual Protein Intake on Body Composition and Muscular Strength in Career Firefighters

“…Despite the extreme physical demands of firefighting, upwards of 80% of firefighters are considered overweight and obese [3], many of whom also express risk factors for cardiovascular disease [22, 23], and do not meet minimum fitness standards [22, 23]. High protein intake has previously been shown to be beneficial for improving body composition and strength [12, 24], yet to date, there has been a lack of quantitative evaluation of protein intake in firefighters. The primary results of the current study demonstrated that firefighters who habitually consumed greater amounts of protein relative to their body weight, tended to have less body fat and a greater %LM.…”

“…Protein intake has been shown to be associated with greater muscle strength, especially when consumed above dietary recommendations [12, 24, 28–33]. In a study by Thompson et al (2015), greater habitual protein intake (g·kg -1 ) was significantly associated with maximal and explosive strength of the leg flexors in blue collar workers [12]. Contrary to these findings, the current study found no significant association between protein intake (average or relative) and isokinetic strength of the leg extensors.…”

“…More importantly, higher protein intake has been shown to be more favorable for improving body composition, promoting fat loss through increases in energy expenditure [9–11]. In blue collar workers, greater habitual protein intake is also associated with greater maximal and explosive strength [12], which is important for firefighter performance [13] and avoiding common injuries (i.e. slips, trips, or falls) in the fire service [14].…”