Age-Related Differences in Body Fat and Fitness of Firefighters Participating in a Health and Wellness Program.

ABSTRACT: Lockie, RG, Dulla, JM, Higuera, D, Ross, K, Orr, RM, Dawes, JJ, and Ruvalcaba, TJ. Age-related differences in body fat and fitness of firefighters participating in a health and wellness program. J Strength Cond Res 38(6): 1127-1135, 2024-Fitness tends to decline, whereas body fat increases, with age, which could impact firefighter occupational performance later in their careers. Health and wellness program participation could reduce these age-related changes. Archival data from 270 firefighters (258 men and 12 women) from a health and wellness program were analyzed. Data included body mass index; body fat percentage (BF%); waist circumference (WC); waist-to-hip ratio (WHR); sit and reach; grip strength; absolute and relative predicted 1 repetition maximum (1RM) leg press; crunches; push-ups; and estimated maximal aerobic capacity (V̇o2max). Firefighters were grouped by age ≤29 (n = 29); 30-34 (n = 44); 35-39 (n = 38); 40-44 (n = 39); 45-49 (n = 48); 50-54 (n = 42); and 55+ (n = 30) years. A univariate analysis of covariance, with sex as a covariate and Bonferroni's post hoc adjustment, determined between-group differences. Effect sizes (d) were calculated. Key results included that the 55+ group had higher BF% and WC compared with the 3 youngest groups (p ≤ 0.002; d = 0.86-1.08). The 50-54 group had higher BF% than the 30-34 group (p = 0.010; d = 0.77). The 55+ group had a greater WHR, lower grip strength, and completed fewer crunches and push-ups than most younger groups (p ≤ 0.05; d = 0.60-1.32). The 50-54 and 55+ groups had a lower 1RM leg press and V̇o2max compared with the younger groups (p ≤ 0.009; d = 0.77-1.79). The program appeared generally effective, with limited differences in groups below 49 years of age. Greater disparities in fat mass and fitness tended to occur in the older groups (50-54, 55+ groups). The data highlighted that older firefighters were participating in the optional program, which could lead to better health outcomes.

Body Composition and Fitness Characteristics of Firefighters Participating in a Health and Wellness Program: Relationships and Descriptive Data.

This study investigated body composition and fitness test relationships from firefighters participating in a health and wellness program and categorized firefighters according to population norms relative to sex and age. Data from 270 firefighters (men = 258, women = 12) were analyzed, including body composition (body mass index [BMI], body fat percentage [BF%], waist circumference [WC], waist-to-hip ratio) and fitness (sit-and-reach, grip strength, leg press, crunches, push-ups, maximal aerobic capacity [V̇O2max]) tests. Mann-Whitney U-test analysis (p < 0.05) showed that male firefighters had a greater WC, WHR, grip strength and leg press. Female firefighters had a greater BF% and better sit-and-reach. Partial correlations controlling for sex indicated 22/24 correlations between body composition and fitness were significant (r = -0.143--0.640). ~52% of firefighters were overweight, and 25% were Obesity Class I-III. ~76% had an increased risk of cardiovascular disease (CVD) considering BMI and WC. ~22% were fatter than average-to-overfat considering BF%. Most firefighters (73-94%) were good-to-excellent in sit-and-reach, grip strength, and push-ups; average-to-well above average in crunches; average-to-above average in leg press; and had good-to-superior V̇O2max. Although most firefighters had better fitness compared to the general population, many had increased CVD risk. The data highlighted the need for comprehensive approaches to improving firefighter health and decreasing CVD risk.

Dietary Caffeine and Polyphenol Supplementation Enhances Overall Metabolic Rate and Lipid Oxidation at Rest and After a Bout of Sprint Interval Exercise.

Jo, E, Lewis, KL, Higuera, D, Hernandez, J, Osmond, AD, Directo, DJ, and Wong, M. Dietary caffeine and polyphenol supplementation enhances overall metabolic rate and lipid oxidation at rest and after a bout of sprint interval exercise. J Strength Cond Res 30(7): 1871-1879, 2016-The purpose of this study was to investigate the effects of a caffeine-polyphenolic supplement on (a) metabolic rate and fat oxidation at rest and after a bout of sprint interval exercise (SIE) and (b) SIE performance. In a double-blind, randomized, placebo-controlled, crossover study and after an initial familiarization visit, 12 subjects (male: n = 11; female: n = 1) (body mass = 76.1 ± 2.2 kg; height = 169.8 ± 1.6 cm; body mass index = 22.7 ± 3.0 kg·m; body fat % = 21.6 ± 2.0%) underwent 2 testing sessions during which time they consumed either a caffeine-polyphenol supplement or placebo. After supplementation, resting energy expenditure, heart rate (HR), and blood pressure (BP) were assessed. Subsequently, subjects performed 30 minutes of SIE while researchers collected performance data. Subjects were then tested for post-SIE energy expenditure, HR, and BP. The caffeine-polyphenol treatment resulted in significantly (p ≤ 0.05) greater energy expenditure (+7.99% rest; +10.16% post-SIE), V[Combining Dot Above]O2 (+9.64% rest; +12.10% post-SIE), and fat oxidation rate (+10.60% rest; +9.76% post-SIE) vs. placebo at rest and post-SIE. No significant differences were detected for peak and average power at all sprint intervals between treatments. Post-SIE HR was significantly (p ≤ 0.05) greater with caffeine-polyphenol supplementation vs. placebo (90.8 ± 3.5 vs. 85.1 ± 3.6 b·min). There were no significant between-treatment differences for BP. It may be concluded that the observed thermogenic response after SIE was directly attributable to caffeine-polyphenol supplementation as opposed to an indirect manifestation of enhanced performance and work output. Collectively, these results corroborate the use of dietary caffeine and polyphenols to support efforts to reduce adiposity and improve overall body composition especially in conjunction with SIE.