ONLINE DRIVERS MEDIA

The study tested only leg exercises, but you can safely expect increased reps on other exercises, as well.

Citrulline? Yes thats the stuff the supplement industry claims to be a better version of arginine. A "super pump supplement", but not necessarily an ergogenic - in spite of the fact that corresponding evidence from rodent and human studies (Briand. 1992; Pérez-Guisado. 2010; Giannesini. 2011) existed years before the study at hand was published (Wax. 2014).

Benjamin Wax and his colleagues from the Mississippi State University and the Auburn University  investigated the effects of citrulline malate supplementation on lower-body resistance exercise performance, blood lactate, heart rate, and blood pressure.

Based on citrulline malate’s chemical composition and a review of the current literature Wax et al. hypothesized that citrulline malate supplementation would mitigate fatigue occurring to the working muscle; therefore, augmenting resistance training performance.
To test their hypothesis the researchers recruited 12 advanced resistance trained male subjects (85kg body weight; <12% body fat; 22.1 ± 1.4 years) and conducted a randomized, counterbalanced, double blind study.

The subjects were randomly assigned to placebo or citrulline malate (8 g; 60 minutes before the workout) groups and then performed repeated bouts of multiple lower body resistance exercise:

"Subjects warmed up on an upright stationary bike (Life Fitness, Brunswick Corporation, Lake Fores, IL) for five minutes, at 60 – 70 revolution/minute with a mass of 3 – 5 kg. Following this warm up, subjects performed two warm up sets (10 repetitions at 90.9 kg and 8 repetitions at 136.4 kg) on the leg press machine. Subjects rested three minutes between sets during the warm up and trial sets.

Next, 60% of each subject’s predetermined 1RM was loaded on the leg press machine and the subject completed as many repetitions as possible until failure occurred. This process was completed for 4 additional sets for a total of 5 sets on the leg press. Next, the subjects performed one warm upset (10 repetitions) on the hack squat machine at a mass of 40.9 kg. This warm up set was followed by 5 sets of 60% of their predetermined 1RM to failure. Finally, following one warm up set (10 repetitions at 36.4 kg) on the leg extension, subjects completed 5 sets of 60% of their 1RM to failure." (Wax. 2014)

The rest periods (recovery periods between sets of exercise), exercise order, and number of sets performed were the same for all subjects in this investigation, for sessions 2 and 3. Blood lactate, heart rate, systolic blood pressure, and diastolic blood pressure were determined pre and post exercise.
The exercise protocol resulted in sequential significant (p < 0.05) decrease in the number of repetitions in all three exercises. However, subjects in the citrulline malate group performed significantly (p < 0.05) higher number of repetitions during all three exercises compared to placebo group.

Figure 1: Wax et al. observed significant increases in maximal leg press, hack squat, and leg extension (not shown) repetitions in response to the ingestion of 8g of citrulline malate 60min before exercise (Wax. 2014)

Blood lactate and heart rate, on the other hand, were significantly increased (p < 0.05) post-exercise in both groups with no significant inter-group differences between citrulline malate and placebo (p > 0.05).
References:

• Briand, Joël, et al. "Use of a microbial model for the determination of drug effects on cell metabolism and energetics: Study of citrulline?malate." Biopharmaceutics & drug disposition 13.1 (1992): 1-22.
• Hickner, Robert C., et al. "L-citrulline reduces time to exhaustion and insulin response to a graded exercise test." Medicine and science in sports and exercise 38.4 (2006): 660-666.
• Giannesini, Benoît, et al. "Citrulline malate supplementation increases muscle efficiency in rat skeletal muscle." European journal of pharmacology 667.1 (2011): 100-104.
• Pérez-Guisado, Joaquín, and Philip M. Jakeman. "Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness." The Journal of Strength & Conditioning Research 24.5 (2010): 1215-1222.
• Verleye, M., et al. "Effects of citrulline malate on bacterial lipopolysaccharide induced endotoxemia in rats." Arzneimittelforschung 45.6 (1995): E712.
• Wax, Benjamin, et al. "Effects of Supplemental Citrulline Malate Ingestion During Repeated Bouts of Lower-body Exercise in Advanced Weight Lifters." The Journal of Strength & Conditioning Research (2014).

It takes some effort to avoid making the transition from the sofa to the ICU.

Whats better for heart disease protection - high or medium intensity exercise as it is still prescribed by the majority of doctors? A recent study from the University of Erlangen-Nürnberg (Germany) probed the effects of high vs. moderate intensity training on cardiovascular risk markers of 81 untrained, healthy not exactly lean (BMI 27.2kg/m²) men aged 30-50 years.

The subjects were randomized to either a high intensity interval training or a moderate intensity steady state training group who burnt the exact same amount of energy during their workouts.
In contrast to other studies, the groups did not train at the same time. The study started in September. From September to December, the HIIT group performed high intensity interval training

• at 80-100% of their maximal heart rate during 90s-120min intervals,
• with 1-3 min pauses at 70-75% of the maximal heart rate

so that 40% of the total training volume were performed at high heart rates, 35% at maximal heart rates, and 25% of the total volume at 25% of medium heart rates.

Figure 1: Overview of the study protocol (translated from Kemmler. 2015).

During the first three months, the medium intensity steady state group (MIST) group served as sedentary control (see Figure 1). A control group in which the markers of cardiovascular health rather deteriorated than improved.

Figure 2: Changes in left ventricular myocardial mass (LVMI), cardiovascular fitness (CV), intima-media thickness (IMT, associated with increased CVD risk), body fat, and lean mass (Kemmler. 2015).

What is of interest is thus not really the difference between the control and the HIIT group, but the difference between the HIIT and MIST group. A difference of which the data in Figure 2 indicates that there was a significant advantage of doing HIIT vs MIST training - at least as far as the cardiovascular disease markers are concerned.

What may come as a surprise is that despite the significant improvements in fitness and metabolic disease scores (-2.06 pts vs. -1.6 pts with HIIT vs. MIST, respectively), the amount of fat lost was more pronounced in the MIST group; and that in spite of the fact that they performed only 5% of their training at the maximal heart frequency, 10% at high intensities and the vast majority of exercise, i.e. 85%, at a moderate exercise intensity. In view of the fact that the design of the study required that all participants expended the same amount of energy, its quite interesting that the subjects in the MIST study burned more body fat than the subjects in the HIIT study. In the absence of a strictly controlled energy intake, its yet no reliable evidence that would disprove the rule that HIIT is - specifically for leaner folks - the more effective fat burner. The result of the study at hand should thus not be overrated.

Figure 2: Endothelial function measured as FMD (left); maximal oxygen uptake (right) before and after 12-week high intensity interval or moderate intensity steady state exercise in patients with heart failure (Wisløff . 2007)

Before I get to the conclusions, I would like to point out that having a exisiting heart condition is not necessarily a reason to refrain from high intensity exercise. On the contrary, a 2007 study by Ulrik Wisløff et al. clearly indicates that aerobic interval training is superior to moderate continuous training even in heart failure patients. More specifically, the scientists from the Norwegian University of Science and Technology in Trondheim found that "[e]xercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity, endothelial function, and quality of life in patients with postinfarction heart failure" (Wisløff. 2007).

Yet in spite of the fact that the researchers  highlight that their results would have "important implications for exercise training in rehabilitation programs" - the impact on the real world prescriptions in such programs is negligible.,
References:

• Beniamini, Yael, et al. "High-intensity strength training of patients enrolled in an outpatient cardiac rehabilitation program." Journal of Cardiopulmonary Rehabilitation and Prevention 19.1 (1999): 8-17.
• Kemmler, Wolfgang, et al. "Hoch-versus moderat-intensive Laufbelastung–Einfluss auf kardio-metabolische Risikogrößen bei untrainierten Männern." DMW-Deutsche Medizinische Wochenschrift 140.01 (2015): e7-e13.
• Tanasescu, Mihaela, et al. "Exercise type and intensity in relation to coronary heart disease in men." Jama 288.16 (2002): 1994-2000.
• Tinkham, Michelle. "Health Promotion in Cardiac Rehabilitation Patients through the Use of a High-Intensity Interval Training Protocol." World Journal of Cardiovascular Diseases 4.10 (2014): 493.
• Warburton, Darren ER, et al. "Effectiveness of high-intensity interval training for the rehabilitation of patients with coronary artery disease." The American journal of cardiology 95.9 (2005): 1080-1084.
• Wisløff, Ulrik, et al. "Superior cardiovascular effect of aerobic interval training versus moderate continuous training in heart failure patients a randomized study." Circulation 115.24 (2007): 3086-3094.