|Six Takeaways From the ACSM Annual Meeting
Len Kravitz, Ph.D.
The American College of Sports Medicine held its 62nd Annual Meeting in San Diego, CA on May 26-30, 2015. According to ACSM (2015), this event is the most comprehensive exercise science and sports medicine conference of its kind in the world. Thousands of professionals from more than 70 disciplines come together from around the globe to exchange research, present new clinical techniques, and share scientific advancements in the areas of public health, physical activity, sports medicine, and exercise science. For this column, 6 studies presented at the annual meeting, which have strong practical applications for IFJ readers, have been selected and reviewed by presenting the question of the study, the research team, the methods and key findings.
Question: How effective is a Tabata kettlebell HIIT program?
The Study: Acute Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training versus Sprint Interval Cycling B.M. Williams and R.R. Kraemer. Southeastern Louisiana University, Hammond, LA.
In this study 8 male participants (age=21 yrs) randomly completed two twelve-minute exercise sessions. In the kettlebell-HIIT (KB-HIIT) session the participants performed three circuits of four exercises (summo squat, kettlebell swings, clean & press, and summo deadlift) using a Tabata protocol (20-sec of exercise followed by 10-sec of rest). In the second exercise session the participants performed a sprint interval cycling (SIC) bout of 30 seconds with an 'all out' effort followed by a 4-min self-selected cycling recovery. Results indicated that the Tabata KB-HIIT protocol elicited a higher oxygen consumption and lower respiratory exchange ratio measurement (subjects were burning slightly more fat during the work bout). Total kilocalorie expenditure was significantly higher during the KB-HITT (144 kcals) versus the SIC bout (122 kcals).
Take Home Message:
KB-HIIT training using a Tabata protocol is a good cardiorespiratory stimulus as well as a meaningful program design component in an exercise for weight management intervention.
Question: How many steps per day are needed to elicit weight loss in obese clients?
The Study: Moderate-to-vigorous Daily Steps Is Associated With Weight Loss In Adults With Obesity. S. Creasy et al. University of Pittsburgh, Pittsburgh, PA. Supported by grant from NIH
Although 10,000 steps per day is commonly recommended for health benefits, this number of accumulated steps per day has not been investigated to see the effect for improved weight loss in obese clients. Researchers recruited 212 adults (age=43 yrs, BMI=32.7 kg/m2) to participate in an 18-month behavior intervention. The intervention included a combination of telephone contacts, in-person meetings, a 1200-1800 kcal/day diet, and walking on most days of the week. Steps per day were assessed with a SenseWear armband. For the data analysis, subjects were grouped based on total steps/day at 18 months as LOW (<7000, n=61), MODERATE (7000 to <10,000, n=72) and HIGH (&Mac179;10,000, n=79). Percent weight loss at 18 months was greatest with the HIGH (12.9% BF loss; 12,994 steps/day) compared to MODERATE (8.4% BF loss; 8451 steps/day) and LOW (7.5% BF loss; 5482 steps/day). Researchers also determined that those subjects who walked at least 10 minutes per day (of their total steps) at a moderate-to-vigorous pace experienced the greatest weight loss success.
Take Home Message: Clients seeking weight loss are encouraged to progressively strive to accumulate 10,000 to 13,000 steps per day, including &Mac179;10 minutes of the daily stepping at a moderate-to-vigorous intensity.
Question: Does carbohydrate mouth rinsing improve exercise performance?
The Study: Does a Carbohydrate Mouth-rinse Improve Endurance Exercise Performance? S.S. Conger et al., University of Pittsburg, Pittsburg, PA.
The idea of swishing a sports drink around in a persons' mouth (and then spitting it out) has been an endurance performance boost concept for over a decade. It is hypothesized that the carbohydrates swirling in the mouth provide a neural stimulus to the brain, which plays a central command role to enhance endurance training as well as to combat exercise fatigue. The rinsing carbohydrate training aid is particularly helpful to endurance enthusiasts who get indigestion from swallowing drinks or solids during a workout or competition. In this study the researchers did a systematic review combined with a meta-analysis to assess the efficacy of a carbohydrate mouth-rinse on endurance performance. After an extensive review of 180 studies the researchers selected 15 studies that met their strict inclusion criteria. Findings indicated that studies using a greater concentration of carbohydrate in the mouth-rinse had the best effect on improving endurance performance.
Take Home Message: Competitive endurance training clients, particularly those who have difficulty digesting foodstuffs during exercise, may realize a slight boost in endurance performance (2-3%) using a carbohydrate rinse product with greater than 6.4% carbohydrate.
Question: How effective is battle rope training for improving cardiorespiratory and muscular fitness?
The Study: The Energy Cost of Battle Rope Exercise J. Verdisco et al. Adelphi University, Garden City, NY
Battle rope (BR) training is a very popular modality currently being utilized in personal training and small group training programs. BR sizes typically range from 1 to 2 inches in diameters and are approximately 30 to 50 feet in length. BR workouts typically involve wrapping the single BR around a fixed anchor point. Thus, a 50 ft battle rope means the exerciser has 25 ft in each arm. Currently, very little published data exist identifying the physiological responses to this type of training. Investigators on this research team recruited 14 college students (7 males, 7 females, age=22 yrs) to perform two different BR movements: alternating-whip (also called alternating waves) and double-whip (also called double waves) with simultaneous squats. Both BR exercises were performed at two different cadences (50 and 70 beats per minute). Each trial consisted of 10 sets of 30 seconds of work (to a metronome) followed by 60 seconds of recovery (14 minutes total trial length) using a 1.5-inch diameter 40-ft rope.
Results are summarized below:
1.Double-whip with Squat at 70 b/min: 27.2 ml/kg/min
2.Double-whip with Squat at 50 b/min: 22.4 ml/kg/min
3.Alternating-whip at 70 b/min: 18.3 ml/kg/min
4.Alternating-whip at 70 b/min: 16.0 ml/kg/min
Heart Rate (b/min)
1.Double-whip with Squat at 70 b/min: 164 b/min
2.Double-whip with Squat at 50 b/min: 152 b/min
3.Alternating-whip at 70 b/min: 131 b/min
4.Alternating-whip at 70 b/min: 138 b/min
Caloric Expenditure (kcals for entire trial and 5 min post exercise)
1.Double-whip with Squat at 70 b/min; 169 kcals
2.Double-whip with Squat at 50 b/min: 138 kcals
3.Alternating-whip at 70 b/min: 105 kcals
4.Alternating-whip at 70 b/min: 94 kcals
The researchers summarize that BR exercise provides a moderate energy expenditure stimulus that appears to elicit a slightly disproportionately high heart rate response due to the intense involvement of the upper body.
Take Home Message: BR training, as a component of a total body workout, provides a meaningful intervention for improving weight loss results and a moderate stimulus for cardiovascular fitness. Many more exercises with BRs can be performed and need to be quantified for their physiological and metabolic values.
Question: Is there a best repetition training zone to optimize hypertrophy with undulating periodization?
Volume-Equated High and Low Repetition Daily Undulating Periodization Models for Lower Body C. Dolan et al., Florida Atlantic University, Boca Raton, FL.
Volume-Equated High and Low Repetition Daily Undulating Periodization Models for Upper Body Muscle Hypertrophy J. Quiles et al. Florida Atlantic University, Boca Raton, FL.
Determining the best repetition zone to optimize hypertrophy is a constant debate with personal trainers. This question has not been investigated using the popular undulating periodization model. Researchers from Florida Atlantic University conducted two different 8-week studies (a lower body and an upper body study) on this topic. The lower body study included 13 males (age=23.14 yrs, wt= 182 lbs) while the upper body study included 15 males (age=22.9, weight=183 lbs). In both studies all subjects had a minimum of 2 yrs. resistance training experience with regular resistance training frequency of &Mac179;1 day/wk. Daily undulating protocols for both studies included randomly dividing the subjects into two different groups:
1) Daily undulating periodization HIGH repetition (DUP-HR): 12 repetitions (Mon), 10 repetitions (Wed), and 8 repetitions (Fri).
2) Daily undulating periodization LOW repetition (DUP-LR) 6 repetitions (Mon), 4 repetitions (Wed), and 2 repetitions (Fri).
Both studies were 8 weeks in length, with the first week being a familiarization and pre-testing week followed by weeks 2-7 of training, and concluding on week 8 with a taper and post-testing. Hypertrophy was assessed pre- and post-training with measures of muscle thickness via ultrasonography (an ultrasound-based diagnostic imaging technique used for visualizing internal body structures such as muscles). In the upper body study, measurements were taken of the left chest and right chest and then summed for total chest. In the lower body study measurements were taken at the vastus lateralis and vastus medialis muscles in the left and right thigh and summed for total thigh muscle thickness. Results in the upper body study showed that both groups had significant improvements in hypertrophy with the DUP-HR increasing 10.8% and DUP-LR improving 8.9%. However, there was no difference between the groups for hypertrophy increase. Similarly, in the lower body study, the DUP-HR and DUP-LR increased muscle thickness 8.2% and 10.8%, respectively. However, no difference was observed between groups.
Take Home Message: Both studies suggest that daily undulating periodization is a very effective approach to increase hypertrophy in previously trained individuals, and not necessarily optimized to a particular repetition zone.
In reflecting about this year's annual_ACSM meeting I believe we are at a pivotal moment in time where significant progress is being made in all areas of exercise and physical activity. The next several years will be most exciting as scientists start making major breakthroughs in many ways that can improve a person's quality of life.
@bio:Len Kravitz, PhD, is the program coordinator of exercise science and a researcher at the University of New Mexico, Albuquerque, where he won the Outstanding Teacher of the Year award. He has received the prestigious Can-Fit-Pro Lifetime Achievement Award and American Council on Exercise Fitness Educator of the Year.
ACSM. ACSM's 62nd Annual meeting
Accessed June 16, 2015