Every year, the science of sports medicine gets better at determining the effectiveness of specific exercise programs—a point made clear at the latest annual meeting of the American College of Sports Medicine.
ACSM’s 62nd annual meeting, held in May 2015 in San Diego, brought together thousands of professionals from around the globe in more than 70 disciplines to exchange research, present new clinical techniques and share scientific advancements in public health, physical activity, sports medicine and exercise science. For this month’s column, I’ll review six studies presented at the meeting that have strong practical applications for
IDEA Fitness Journal
readers. These are the questions and answers the studies explored:
How Effective Is a Tabata Kettlebell-HIIT Program?
Acute Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training vs. Sprint Interval Cycling. B.M. Williams
R.R. Kraemer, Southeastern Louisiana University, Hammond, Louisiana.
Eight men (average age 21) randomly completed two 12-minute exercise sessions. In the kettlebell-HIIT (KB-HIIT) session, the men performed three circuits of four exercises (sumo squat, kettlebell swings, clean
press and sumo dead lift) using a Tabata protocol (20 seconds of exercise followed by 10 seconds of rest). In the second exercise session, the participants performed three 30-second sprint interval cycling (SIC) bouts at an “all-out” effort, each followed by a 4-minute self-selected cycling recovery.
Results indicated that the Tabata KB-HIIT protocol elicited higher oxygen consumption and a lower respiratory exchange ratio (subjects were burning slightly more fat during the work bout). Total kilocalorie expenditure was significantly higher during the KB-HITT (144 kcal) than in the SIC bout (122 kcal).
KB-HIIT training using a Tabata protocol is a good cardiorespiratory stimulus and a meaningful program design component in an exercise intervention for weight management.
How Many Steps per Day Are Needed to Elicit Weight Loss in Obese Clients?
Moderate-to-Vigorous Daily Steps Is Associated With Weight Loss in Adults With Obesity. S. Creasy, K.K. Davis
J.M. Jakicic, University of Pittsburgh. Supported by a grant from the National Institutes of Health.
Although a goal of 10,000 steps per day is commonly recommended for health benefits, whether this number of steps per day improves weight loss in obese clients has not been investigated. Researchers recruited 212 adults (average age 43; average BMI 32.7 kg/m2) to participate in an 18-month behavior intervention that included a combination of telephone contacts, in-person meetings, a diet of 1,200–1,800 kcal per day, and walking on most days of the week.
Steps per day were assessed with a SenseWear armband. For the data analysis at 18 months, subjects were grouped based on total steps per day as LOW (under 7,000,
= 61), MODERATE (7,000–10,000,
= 72) or HIGH (more than 10,000,
Percent weight loss at 18 months was greatest in the HIGH group (12.9% BF loss; 12,994 steps/day), followed by the MODERATE group (8.4% BF loss; 8,451 steps/day) and then the LOW group (7.5% BF loss; 5,482 steps/day). Researchers determined that subjects who walked at least 10 minutes per day (of their total steps) at a moderate to vigorous pace had the greatest weight-loss success.
Clients seeking weight loss are encouraged to progressively strive to accumulate 10,000–13,000 steps per day, including at least 10 minutes of stepping at a moderate to vigorous intensity.
Does Carbohydrate Mouth Rinsing Improve Exercise Performance?
Does a Carbohydrate Mouth-Rinse Improve Endurance Exercise Performance? S.S. Conger, M.E. Darnell
S.M. Fulkerson, University of Pittsburg.
Swishing a sports drink around in the 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 in enhancing endurance training and combating fatigue. Carbohydrate mouth rinsing is particularly helpful to endurance enthusiasts who get indigestion from swallowing drinks or solids during a workout or competition.
In this study, the researchers combined a systematic review with a meta-analysis to assess whether carbohydrate mouth rinsing affected endurance performance. After an extensive review of 180 studies, the researchers selected 15 studies that met their strict inclusion criteria. Findings indicated that mouth rinses using higher concentrations of carbohydrate improved endurance performance the most.
Competitive endurance training clients, particularly those who have difficulty digesting foodstuffs during exercise, may realize a slight boost in endurance performance (2%–3%) by using a mouth rinse product with a carbohydrate concentration greater than 6.4%.
How Effective Is Battle Rope Training for Improving Cardiorespiratory and Muscular Fitness?
The Energy Cost of Battle Rope Exercise. J. Verdisco et al., Adelphi University, Garden City, New York.
Battle rope (BR) training is very popular in personal training and small-group training programs. BRs generally range from 1 to 2 inches in diameter and are approximately 30–50 feet long. BR workouts typically involve wrapping a single BR around a fixed anchor point. Thus, a 50-foot battle rope means the exerciser has 25 feet in each arm.
There is little published data on the physiological responses to this type of training. Investigators on this research team recruited 14 college students (7 men and 7 women; average age 22) to perform two BR movements: alternating whip (also called alternating waves) and double whip (also called double waves) with simultaneous squats. Both BR exercises were performed at 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 (total trial length: 14 minutes) using a 40-foot rope with a 1.5-inch diameter.
Results are summarized below in average values:
The researchers concluded that BR exercise provides a moderate energy expenditure stimulus that appears to elicit a slightly disproportionately high heart rate response because of the intense involvement of the upper body.
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.
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, Florida.
- Volume-Equated High and Low Repetition Daily Undulating Periodization Models for Upper Body Muscle Hypertrophy. J. Quiles et al., Florida Atlantic University, Boca Raton, Florida.
Personal trainers perpetually debate which repetition zone is best for optimizing hypertrophy. This question has not been investigated using the popular undulating periodization model. Researchers at Florida Atlantic University conducted two 8-week studies (a lower-body study and an upper-body study) on this topic.
The lower-body study included 13 men (average age 23, average weight 182 pounds) while the upper-body study included 15 men (average age 23, average weight 183 pounds). In both studies, all the men had a minimum of 2 years of resistance training experience with regular resistance training frequency of at least 1 day per week. Daily undulating multiset protocols for both studies included randomly dividing the subjects into two groups:
- Daily undulating periodization HIGH repetition (DUP-HR): 12 repetitions (Monday), 10 repetitions (Wednesday) and 8 repetitions (Friday).
- Daily undulating periodization LOW repetition (DUP-LR): 6 repetitions (Monday), 4 repetitions (Wednesday) and 2 repetitions (Friday).
To equate training volume between the two groups, the researchers began by equating relative volume (sets
intensity of each subject’s 1-repetition maximum). Below is an example how this is done:
12 reps @ 60% 1-RM
0.6 = 28.8)
10 reps @ 65% 1-RM
0.65 = 26)
8 reps @ 70% 1-RM
0.7 = 28)
Equated to a relative volume of 82.8.
6 reps @ 75% 1-RM
0.75 = 36)
4 reps @ 80% 1-RM
0.8 = 28.8)
2 reps @ 85% 1-RM
0.85 = 17)
Equated to a relative volume of 81.8.
Both studies lasted 8 weeks, with the first week devoted to familiarization and pretesting, followed by 6 weeks of training and concluding in week 8 with a taper and posttesting. Hypertrophy was assessed before and after training with measures of muscle thickness via ultrasonography (an ultrasound-based diagnostic imaging technique used to visualize 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 thighs and summed for total thigh-muscle thickness.
Results in the upper-body study showed that both groups made significant improvements in hypertrophy, with the DUP-HR group increasing 10.8% and the DUP-LR group improving 8.9%. However, the difference in hypertrophy increase between the groups was not scientifically significant. Similarly, in the lower-body study, the DUP-HR and DUP-LR groups increased muscle thickness 8.2% and 10.8%, respectively, but no significant difference was observed between groups.
Both studies suggest that daily undulating periodization is very effective at increasing hypertrophy in previously trained individuals, and that results are not necessarily optimized by choosing a particular repetition zone.
In reflecting on this year’s annual ACSM meeting, I believe we have reached a pivotal moment where significant progress is taking place 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.