A Description of Exercise Programs Implemented During a Firefighter Training Academy.

OBJECTIVE: The aim of the study is to thoroughly describe exercise programs that were performed during a firefighter training academy, including their effects on body composition and physical fitness. METHODS: Fourteen recruits performed exercise programs during a 24-week training academy and several components of their body composition and physical fitness were measured. Moreover, their heart rate (HR) and session rating of perceived exertion (sRPE) were recorded during and after every training session, respectively. RESULTS: Fat-free mass, subcutaneous fat in the abdomen, cardiovascular fitness, flexibility, lower-body power, and muscular endurance significantly improved during the study ( P ≤ 0.05). The highest HR and sRPE responses were observed during aerobic training (AT) sessions. The average HR responses relative to maximum HR were similar during AT, high-intensity circuit training, multimodal high-intensity interval training, and high-intensity functional training; however, the sRPEs during high-intensity circuit training and multimodal high-intensity interval training were significantly lower than AT. CONCLUSIONS: Several effective exercise programs can be implemented during firefighter training academies.

Utilizing multimodal high-intensity interval training for a firefighter training academy during the COVID-19 pandemic.

BACKGROUND: Firefighters typically undergo a 16-24-week training academy during which they perform a variety of traditional exercise programs such as cardiovascular, resistance, and concurrent training. Because of limited facility access, some fire departments seek alternative exercise programs, such as multimodal high-intensity interval training (MM-HIIT), which essentially combines resistance and interval training. OBJECTIVE: The primary purpose of this study was to assess the effect of MM-HIIT on body composition and physical fitness in firefighter recruits who completed a training academy during the coronavirus (COVID-19) pandemic. A secondary purpose was to compare the effects of MM-HIIT to previous training academies that implemented traditional exercise programs. METHODS: Healthy and recreationally-trained recruits (n = 12) participated in 2-3 days/week of MM-HIIT for 12 weeks and had several components of body composition and physical fitness measured before and after the program. Because of COVID-19-related gym closures, all MM-HIIT sessions were performed outdoors at a fire station with minimal equipment. These data were retroactively compared to a control group (CG) that previously completed training academies with traditional exercise programs. RESULTS: Subjects in the MM-HIIT group significantly improved several components of body composition and fitness, including fat mass, fat-free mass, body fat percentage, aerobic capacity, and muscular endurance. Moreover, there were no significant differences for any dependent variable when MM-HIIT was compared to the CG. CONCLUSION: These results suggest that MM-HIIT may serve as an effective substitute for traditional concurrent training paradigms that are typically used for firefighter academies.

The effect of repetition tempo on cardiovascular and metabolic stress when time under tension is matched during lower body exercise.

PURPOSE: To investigate the effect of repetition tempo on cardiovascular and metabolic stress when time under tension (TUT) and effort are matched during sessions of lower body resistance training (RT). METHODS: In a repeated-measures, cross-over design, 11 recreationally trained females (n = 5) and males (n = 6) performed 5 sets of belt squats under the following conditions: slow-repetition tempo (SLOW; 10 reps with 4-s eccentric and 2-s concentric) and traditional-repetition tempo (TRAD; 20 reps with 2-s eccentric and 1-s concentric). TUT (60 s) was matched between conditions and external load was adjusted so that lifters were close to concentric muscular failure at the end of each set. External load, total volume load (TVL), impulse (IMP), blood lactate, ratings of perceived exertion (RPE), HR, and muscle oxygenation were measured. RESULTS: Data indicated that TVL (p < 0.001), blood lactate (p = 0.017), RPE (p = 0.015), and HR (p < 0.001) were significantly greater during TRAD while external load (p = 0.030) and IMP (p = 0.002) were significantly greater during SLOW. Whether it was expressed as minimal values or change scores, muscle oxygenation was not different between protocols. CONCLUSION: When TUT is matched, TVL, cardiovascular stress, metabolic stress, and perceived exertion are greater when faster repetition tempos are used. In contrast, IMP and external load are greater when slower repetition tempos are used.

Metabolic Profile of Reciprocal Supersets in Young, Recreationally Active Women and Men.

ABSTRACT: Realzola, RA, Mang, ZA, Millender, DJ, Beam, JR, Bellovary, BN, Wells, AD, Houck, JM, and Kravitz, L. Metabolic profile of reciprocal supersets in young, recreationally active females and males. J Strength Cond Res 36(10): 2709-2716, 2022-Reciprocal supersets (RSSs) are a time-efficient style of resistance exercise (RE) that consist of performing 2 consecutive exercises with opposing muscle groups while limiting rest times between them. Previous research in men indicates a RSS has an increased physiological response when compared with traditional RE (TRAD). No between-sex comparison of metabolic data for RSSs exists. The purpose of this study was to create a metabolic profile for RSSs in men and women. Eighteen resistance-trained individuals underwent 2 bouts of volume-load equated RE: RSS and TRAD. Reciprocal superset exercises were split into 3 clusters: (a) hexagonal bar deadlift superset with leg press, (b) chest press superset with seated row, and (c) overhead dumbbell press superset with latissimus dorsi pull-downs. The TRAD protocol, doing the same exercises, emulated hypertrophy emphasis training. Oxygen uptake (V̇ o2 ), heart rate (HR), blood lactate ([BLa]), rate of perceived exertion (RPE), and excess post-exercise oxygen consumption (EPOC) were measured. Aerobic and anaerobic energy expenditure were estimated using V̇ o2 and lactate, respectively. The level of significance set for this study was p ≤ 0.05. Regardless of sex, a RSS elicited significantly greater average V̇ o2 , HR, [BLa], RPE, and anaerobic and aerobic energy expenditures, and was completed in a shorter time compared with TRAD ( p ≤ 0.05). When compared with women, men had significantly greater EPOC, average [BLa], and anaerobic and aerobic energy expenditures during RSSs ( p ≤ 0.05). The average [BLa] and aerobic energy expenditure of the men were also significantly greater than the women during TRAD ( p ≤ 0.05). This study suggests that a RSS is a metabolically demanding RE session that may elicit increases in musculoskeletal, cardiorespiratory, and physiological adaptations while decreasing the duration of exercise.

A Metabolic Profile of Peripheral Heart Action Training.

Purpose: Peripheral heart action (PHA) is a style of circuit training that alternates upper and lower body resistance exercises with minimal rest between sets. The purpose of this study was to compare the metabolic demands of PHA to traditional hypertrophy training (TRAD) and to provide between sex comparison for both types of resistance training (RT). Methods: Twenty resistance-trained individuals underwent two bouts of volume-load matched RT: PHA and TRAD. We measured oxygen uptake (VO2), heart rate (HR), blood lactate (BL) concentration, rating of perceived exertion (RPE), excess post-exercise oxygen consumption (EPOC), and duration of each session. Results: PHA elicited significantly greater %VO2max (p < .001), %HRmax (p < .001), RPE (p < .001), and EPOC (p < .001) compared to TRAD. PHA was also completed in less time (p < .001). Compared to TRAD, BL was significantly higher at mid-exercise (p < .001), post-exercise (p < .001), and 5-min post-exercise (p < .001) during PHA. There were no between-sex differences for BL at any time-point for TRAD. However, during PHA, BL was significantly higher for males at mid-exercise (p = .04), post-exercise (p = .02), and 5-min post-exercise (p = .002). No between-sex differences were detected for HR, VO2, RPE, or duration for either style of RT. Conclusions: PHA is a time-effective and metabolically demanding circuit that may lead to strength and cardiorespiratory adaptations. Males produced more BL than females during PHA, but not TRAD, suggesting that they incurred more metabolic stress during the bout of circuit training.

The Effect of Rest Interval Length on Upper and Lower Body Exercises in Resistance-Trained Females.

The purpose of this study was to investigate the effects of SHORT (1 min) and LONG (3 min) rest intervals (RI) on total volume lifted (TVL), repetition performance, fatigue index (FI), and blood lactate [La] during upper body (chest press) and lower body (leg press) exercise with low-intensity (75% of a 10-RM) in trained female lifters. Fourteen females (mean ± SD, age = 22.9 ± 5.4 years, training experience = 5.2 ± 2.5 years, height = 166.1 ± 6.9 cm, weight = 61.3 ± 5.1 kg, body fat % = 21.7 ± 3.3%) participated in this randomized, repeated-measures, cross-over design study. They performed four sets to failure on chest press (CP) and leg press (LP) under two conditions (SHORT and LONG RIs) in a counterbalanced manner. Paired-samples t-tests were used to analyze mean differences for TVL in CP and LP, separately. A 2 (exercise) x 2 (rest interval) repeated measures ANOVA was used to analyze mean differences in FI and average [La] values. A 2 (rest interval) x 4 (sets) repeated measures ANOVA was used to analyze mean differences in repetitions completed for each exercise. TVL for SHORT was significantly less when compared to LONG for both exercises. There was no significant difference in average [La] between RIs despite a greater FI in SHORT compared to LONG for both exercises. Lastly, [La] was higher during LP compared to CP irrespective of RI length. These results suggest that longer RIs are better for female lifters who want to optimize TVL with low-intensity resistance training. Metabolic stress, as measured by blood lactate, was greater during lower-body exercise.

Harness Suspension Stress: Physiological and Safety Assessment.

: Hanging motionless in a full body harness may result in unwanted events, such as acute hypotension and syncope, which has been termed harness suspension stress (HSS). The etiology of HSS has not been explored, and it is unknown if the type of harness influences the HSS response. OBJECTIVES: Evaluate hemodynamics, subjective discomfort, and biological markers of muscle damage during 30-minutes suspension; and evaluate differences between harness attachment (frontal or dorsal). METHODS: Heart rate, blood pressure, biological markers of muscle damage, and subjective discomfort were measured. RESULTS: Trial time was shorter in the dorsal versus frontal point of attachment. Hemodynamic shift resulted in the dorsal trial which indicated possible perfusion abnormalities. CONCLUSIONS: Hemodynamic adjustments contributed to early termination observed in the dorsal trial. A frontal point of attachment may be more suitable for extended harness exposure.

Effect of novel dietary supplement on metabolism in vitro and in vivo.

Obesity is an increasingly prevalent and preventable morbidity with multiple behavioral, surgical and pharmacological interventions currently available. Commercial dietary supplements are often advertised to stimulate metabolism and cause rapid weight and/or fat loss, although few well-controlled studies have demonstrated such effects. We describe a commercially available dietary supplement (purportedly containing caffeine, catechins, and other metabolic stimulators) on resting metabolic rate in humans, and on metabolism, mitochondrial content, and related gene expression in vitro. Human males ingested either a placebo or commercially available supplement (RF) in a randomized double-blind placebo-controlled cross-over fashion. Metabolic rate, respiratory exchange ratio, and blood pressure were measured hourly for 3 h post-ingestion. To investigate molecular effects, human rhabdomyosarcoma cells (RD) and mouse myocytes (C2C12) were treated with various doses of RF for various durations. RF enhanced energy expenditure and systolic blood pressure in human males without altering substrate utilization. In myocytes, RF enhanced metabolism, metabolic gene expression, and mitochondrial content suggesting RF may target common energetic pathways which control mitochondrial biogenesis. RF appears to increase metabolism immediately following ingestion, although it is unclear if RF provides benefits beyond those provided by caffeine alone. Additional research is needed to examine safety and efficacy for human weight loss.

Increased meal frequency attenuates fat-free mass losses and some markers of health status with a portion-controlled weight loss diet.

Increased meal frequency (MF) may be associated with improvements in blood markers of health and body composition during weight loss; however, this claim has not been validated. The purpose of the study was to determine if either a 2-meal (2 MF) or 6-meal frequency (6 MF) regimen can improve body composition and blood-based markers of health while consuming a portion-controlled equihypocaloric diet. Eleven (N=11) obese women (52 ± 7 years, 101.7 ± 22.6 kg, 39.1 ± 7.6 kg/m(2)) were randomized into treatment condition (2 MF or 6 MF) for 2 weeks, completed a 2-week washout, and alternated treatment conditions. In pre/post fashion, changes in body composition, glucose, insulin, and lipid components were measured in response to a test meal. Body mass was successfully lost (P ≤ .05) under both feeding regimens (2 MF: -2.8 ± 1.5 vs 6 MF: -1.9 ± 1.5 kg). Altering MF did not impact glucose, insulin, total cholesterol, or low-density lipoprotein cholesterol (P>.05). On average, fat-free mass (FFM) decreased by -3.3% ± 2.6% following the 2 MF condition and, on average, increased by 1.2% ± 1.7% following the 6 MF condition (P ≤ .05). Fasting high-density lipoprotein cholesterol (HDL-C) percentage increased during the 2 MF condition; this was significantly greater than that in the 6 MF condition (1.3% ± 12.2% vs 0.12% ± 10.3%) (P ≤ .05). Overall, reductions in MF (2 MF) were associated with improved HDL-C levels; but the clinical significance is not clear. Alternatively, increased MF (6 MF) did appear to favorably preserve FFM during weight loss. In conclusion, caloric restriction was effective in reducing body mass and attenuating FFM changes in body composition; however, glucose, insulin, and lipid metabolism had no significant differences between MF.

Effect of post-exercise caffeine and green coffee bean extract consumption on blood glucose and insulin concentrations.

OBJECTIVE: The aim of this study was to investigate the effects of ingesting caffeine and green coffee bean extract on blood glucose and insulin concentrations during a post-exercise oral glucose tolerance test. METHODS: Ten male cyclists (age: 26 ± 5 y; height: 179.9 ± 5.4 cm; weight: 77.6 ± 13.3 kg; body mass index: 24 ± 4.3 kg/m(2); VO2 peak: 55.9 ± 8.4 mL·kg·min(-1)) participated in this study. In a randomized order, each participant completed three 30-min bouts of cycling at 60% of peak power output. Immediately after exercise, each participant consumed 75 g of dextrose with either 5 mg/kg body weight of caffeine, 10 mg/kg of green coffee bean extract (5 mg/kg chlorogenic acid), or placebo. Venous blood samples were collected immediately before and after exercise during completion of the oral glucose tolerance test. RESULTS: No significant time × treatment effects for blood glucose and insulin were found. Two-h glucose and insulin area under the curve values, respectively, for the caffeine (658 ± 74 mmol/L and 30,005 ± 13,304 pmol/L), green coffee bean extract (637 ± 100 mmol/L and 31,965 ± 23,586 pmol/L), and placebo (661 ± 77 mmol/L and 27,020 ± 12,339 pmol/L) trials were not significantly different (P > 0.05). CONCLUSION: Caffeine and green coffee bean extract did not significantly alter postexercise blood glucose and insulin concentrations when compared with a placebo. More human research is needed to determine the impact of these combined nutritional treatments and exercise on changes in blood glucose and insulin.

The effects of a harness safety system during maximal treadmill run testing in collegiate middle- and long-distance runners.

This study compared the results of graded maximal treadmill testing with and without a safety harness (SH) spotting system among collegiate middle- and long-distance runners. Thirteen (n = 8 men, n = 5 women) collegiate runners completed 2 randomly selected maximal treadmill tests. One trial used an SH, and one trial used no harness. All tests were separated by at least 48 hours. The subjects began the test at a velocity of 14.5 or 12 km · h with 1% grade for men and women, respectively, and increased 0.80 kilometers/hr per stage. During each trial, metabolic data and running speed values were recorded along with the completion of a safety questionnaire. No significant difference was found for maximal oxygen consumption (60.84 ± 8.89 vs. 60.733 ± 9.38 ml · kg · min) and velocity at maximal oxygen consumption (5.33 ± 0.62 vs. 5.24 ± 0.57 m · s) between the no harness and harness trials, respectively. Test time was found to be significantly longer in the no harness trial (611.06 ± 119.34 vs. 537.38 ± 91.83 seconds, p < 0.05). The results of the safety questionnaire demonstrated that the runners felt significantly more comfortable during the SH trial (p < 0.05).

Effect of various warm-up devices on bat velocity of intercollegiate softball players.

Numerous warm-up devices are available for use by softball players while they are in the on-deck circle. It is difficult to know which warm-up device produces the greatest bat velocity (BV) in the batter's box for softball players because on-deck studies with these individuals are sparse. Because the majority of warm-up device research has been conducted with baseball players, the primary purpose of this study was to examine the effect of various warm-up devices on the BV of female intercollegiate softball players and compare the results with those of male baseball players. A secondary purpose was to evaluate 2 new commercially available resistance devices as warm-up aids. Nineteen Division I intercollegiate softball players (age = 19.8 ± 1.2 years, height = 167.0 ± 4.7 cm, body mass = 69.2 ± 8.6 kg, lean body mass = 49.6 ± 3.6 kg, % body fat = 27.9 ± 5.9) participated in a warm-up with 1 of 8 resistance devices on separate days. Each of the 8 testing sessions had players perform a standardized dynamic warm-up, 3 maximal dry swings mimicking their normal game swing with the assigned warm-up device, 2 comfortable dry swings with a standard 83.8-cm, 652-g (33-in., 23-oz) softball bat followed by 3 maximal game swings (20-second rest between swings) while hitting a softball off a batting tee with the same standard softball bat. Results indicated that there were no statistically significant differences in BV after using any of the 8 warm-up devices (510.3-2,721.5 g or 18-96 oz) similar to in previous baseball research. This indicates that the results for both male and female intercollegiate players are similar and that intercollegiate softball players can use any of the 8 warm-up devices in the on-deck circle and have similar BVs. However, similar to in other previous baseball research, it is not recommended that female intercollegiate softball players warm up with the popular commercial donut ring in the on-deck circle because it produced the slowest BV.

Effect of various warm-up devices on bat velocity of intercollegiate baseball players.

A variety of warm-up devices are available to baseball players to use before their game at-bat. Past baseball research evaluating warm-up devices indicates that implements that are ±12% of standard game bat weight produce the greatest bat velocities for high school and intercollegiate players. The purpose of this study was to examine the effect of various warm-up devices on bat velocity (BV) of intercollegiate baseball players. Twenty-two Division I intercollegiate baseball players (age = 20.0 ± 1.5 years, height = 182.6 ± 8.3 cm, body mass = 91.4 ± 11.4 kg, lean body mass = 78.8 ± 8.9 kg, % body fat = 13.6 ± 3.8) participated in a warm-up with 1 of 10 weighted devices on separate days. Each of the 10 testing sessions consisted of a standardized warm-up, 3 dry swings as hard as possible with the assigned warm-up device, 2 comfortable dry swings with a standard game baseball bat followed by 3 game swings (20-second rest between swings) while hitting a baseball off of a batting tee with the same standard game baseball bat. Results indicated that there were no statistically significant differences in BV after using any of the 10 warm-up devices. For male intercollegiate baseball players, results indicate that warm-up devices varying from 623.7 to 2,721.5 g (22-96 oz.) did not change mean BV of a standard game baseball bat, suggesting that intercollegiate players can use any of the 10 warm-up devices in the on-deck circle and maintain their BV. Therefore, personal preference as to which warm-up implement to use in the on-deck circle is advised.

Validity of 2 skinfold calipers in estimating percent body fat of college-aged men and women.

There is a need for cost-effective techniques that accurately predict percent body fat (%BF) and require little skill to administer. There are 2 commercially available skinfold calipers, 1 digital and the other self-administered, that claim to accurately predict %BF. The primary purpose of this study was to validate these calipers using dual-energy x-ray absorptiometry (DXA) as a reference method in a sample of college-aged men and women. A secondary purpose of this study was to compare the validity of these calipers to the validity of arm-to-arm bioempedance analysis (BIA) (Omron, Shelton, Connecticut, U.S.A.), leg-to-leg BIA (Tanita, Arlington Heights, Illinois, U.S.A.), and 3-site skinfold equations (SUM3) using DXA as a reference method. Fifty college students (25 men and 25 women) from a kinesiology department who ranged in fitness levels volunteered to have %BF measured by the digital and self-administered skinfold calipers, Omron, Tanita, and SUM3. The digital and self-administered skinfold calipers had the poorest group predictive accuracy for the men and women (total error ranged from 7.9 to 10.9%BF) when compared to the other field methods. The digital skinfold caliper had good individual predictive accuracy in the men (95% limits of agreement [LOA] = ± 6.4%BF) and women (95% LOA = ± 4.9%BF) when compared to the other field methods. However, the self-administered skinfold caliper had poor individual predictive accuracy for the men (LOA = ± 8.6%BF) and the women (LOA = ± 7.5%BF) when compared to the other field methods. Compared to DXA, Tanita, Omron, and SUM3, we would not recommend using the digital or self-administered skinfold calipers for estimating %BF in college-aged men and women with similar body composition as the men and women in this study. We recommend using the SUM3 to estimate %BF.

A biomechanical analysis of the squat between competitive collegiate, competitive high school, and novice powerlifters.

The purpose of this study was to measure and analyze kinematic differences between competitive collegiate (CLG, n = 9) powerlifters, competitive high school (HS, n = 9) powerlifters, and novice (NV, n = 11) powerlifters during a maximal squat to determine the effect of skill level on performance. All powerlifters performed 3 squats, with the final squat being their 1 repetition maximum. Kinematic data (descent, ascent, total lift times, knee angle magnitude, knee angular velocity, and knee angular acceleration) was measured using 2-dimensional motion analysis equipment. Differences in mean peak kinematic values between the 3 groups were analyzed using a 1-way multivariate analysis of variance, p