Blood Flow Restricted LISS, but not HIIT, Will Boost VO2Max (5%), as Well as Strength (20%) - Perfect for Athletes' Rehab

I have to admit: Unless you're injured and in rehab or belong to any other group of athletes where high mechanical loading is contraindicated or impractical, BFR is not exactly something you "have" to do, because everything else was worse.

If you want to improve both strength and conditioning, there is usually no way to train accordingly, i.e. do "cardio" (aerobic training) at high(er) intensities and lift weight (enough to make gains). But is this actually true? What about HIIT, for example? Could that help increase both, VO2max and strength at the same time? How intense do you have to train and does adding cuffs and blood flow restriction have a value of its own?

In their latest study, a group of Brazilian scientists tried to answer these and related questions. In short: de Oliveira et al. (2016) tested the VO2max and strength response to both, low intensity blood flow restricted training, high intensity interval training (HIT) and regular low intensity "cardio".

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To this ends, the researchers recruited thirty-seven recreationally active (but not endurance trained) subjects (23.8 ± 4 years; 171.7 ± 9.5 cm; 70 ± 11 kg) who were then assigned to one of four groups: low-intensity interval training with (BFR, n = 10) or without (LOW, n = 7) blood flow restriction, high-intensity interval training (HIT, n = 10), and combined HIT and BFR (BFR + HIT, n = 10, every session performed 50% as BFR and 50% as HIT).

Figure 1: Graphical illustration of the study de Oliviera et al. used in their recent experiment (de Oliveira. 2016).

Here are the details: For all groups (BFR, HIT, HIT + BFR, and LOW) the training program consisted of three exercise sessions per week on a stationary cycle ergometer for a total duration
of 4 weeks. For all training groups, every training session was preceded by 5-min warm-up at 30% of Pmax. The training power output was 30% of Pmax for LOW and BFR training groups.

Each training session consisted of two sets of five "repetitions" (meaning intervals of exercise) for the first three sessions, after which one repetition per set was added each week. Therefore, in the fourth training week, the session consisted of two sets of eight repetitions. Each repetition lasted 2 min, interspersed by 1-min passive rest. The rest interval between sets was 5 min (3-min active recovery at 30% Pmax followed by 2-min passive rest). The individual protocols are descibed as follows:

• The BFR group wore pressure cuff belts (18 cm wide, Missouri, São Paulo, Brazil) on the proximal portion of both thighs during all training sessions. In the first week, cuff belts were inflated to 140 mmHg during the 2-min repetitions and deflated during the 1-min rest periods. The pressure was progressed by 20 mmHg after three completed sessions, thus, in the last week, the pressure applied was 200 mmHg. 
• In the HIT group, the subjects completed a variable power output training protocol. Each repetition began at 110% Pmax with a progressively 5% decrease in the intensity every 30 s (110%, 105%, 100%, and 95% Pmax, respectively). This training protocol was designed to increase the average power output of the training, as fast-start protocols have shown faster VO2p kinetics and higher exercise tolerance compared with constant work rate exercise (Turnes et al., 2014). 
• For BFR + HIT one set was performed as BFR and the other as HIT. The order of the sets was alternated at every session and the total exercise time was the same for all training protocols.

As previously hinted at, both, the maximal oxygen uptake (VO2max), as well as the maximal power output (Pmax), the onset blood lactate accumulation (OBLA), and the muscle strength were measured for all subjects, before and after 4 weeks training (3 days a week).

Figure 2: Only the low intensity BFR training triggered both fitness and strength gains.

As you can see in Figure 2, all training groups were able to improve the onset blood lactate in W/kg accumulation (OBLA | BFR, 16%; HIT, 25%; HIT + BFR, 22%; LOW, 6%), with no difference between groups. The subjects' fitness as measured by VO2max and Pmax, however, improved only for BFR (6%, 12%), HIT (9%, 15%) and HIT + BFR (6%, 11%) - statistically speaking without inter-group differences.

Table 1: Description of training | Perceived exertion, [La], Peak HR and Peak VO2 represent the mean of avg. exercise values obtained during the 1st & 12th training session. Rating of perceived exertion on 0 to 10 scale (de Oliviera. 2016).

In contrast to the conditioning which improved in all but the light intensity trial, however, muscle strength gains were observed only after BFR training (11%) - not without effort, though, as the data in Table 1 indicates. After all, the perceived exertion at only 66W with your legs cuffed all up is almost identical to the one in the HIT group with its sign. higher avg. intensity of 236 Watts.

1st Blood-Flow Restriction + Classic Training Periodization Study is There and the Gains are Impressive - The aim of the study was to investigate how a periodized combination of classic resistance and blood flow restricted resistance exercise | read it

What's the use? I don't think that healthy trainees will really benefit from BFR conditioning + strength work. For injured athletes who can still master the exerting, intensity-wise less demanding training, it could yet be an ideal means to maintain or even increase both optimal conditioning and muscle strength.

In that, it is important to remember that the "BFR training volume seems to be imptant to determine the adaptive responses associated with muscle strength gains" (de Oliviera. 2016) - this is an important conclusion the authors base on the observation that "the 50% BFR training volume performed by BFR + HIT was not sufficient to induce increases in muscle strength" (ibid.) | Comment!

References:

• de Oliveira, Mariana Fernandes Mendes de, et al. "Short‐term low‐intensity blood flow restricted interval training improves both aerobic fitness and muscle strength." Scandinavian Journal of Medicine & Science in Sports (2015).
• Loenneke, Jeremy P., et al. "Effects of cuff width on arterial occlusion: implications for blood flow restricted exercise." European journal of applied physiology 112.8 (2012): 2903-2912.
• Sundberg, Carl Johan. "Exercise and training during graded leg ischaemia in healthy man with special reference to effects on skeletal muscle." Acta physiologica Scandinavica. Supplementum 615 (1993): 1-50.

Impingement No More: Study Outlines 6 Week Protocol That Reduces, in 15% of the Cases Even Resolves Shoulder Pain

Image 1: A 1990 study by Lo et al. reports that 43.8% of athletes who are competing in sports with upper arm involvement complain about shoulder problems, 29% with constant pain (Lo. 1990)!

If you are thinking about sex, lies, ex-presidents and obese interns at the White House, when you hear the word "impingement" your language proficiency is not the best and / or you are one of those guys (or girls) who prefers his gossip weekly over the latest issue of a fitness, let alone a bodybuilding magazine (unlikely for SuppVersity students, but who knows?). If you don't belong to this group and / or have just begun to massage your aching shoulder, however, the results of a recently published study on the effectiveness of a 6-week scapular muscle rehabiliation exercise regimen that was specifically designed to alleviate the pain and improve the limited flexibility of athletes with mild to moderate shoulder impingement could be of great interest to you.

The scientifically proven 6-week anti-impingement protocol

For their trial, K. De May and his colleagues from the Department of Rehabilitation Sciences and Physiotherapy of the Faculty of Medicine and Health Sciences at the University Hospital in Ghent, Belgium, recruited 47 athletes (25 men and 22 women; mean 24.6 years); BMI 22.70kg/m²) who had been spending 6+ hours a week playing competitive overhead sports [volleyball (17), tennis (10), canoe polo (2), baseball (2), swimming (11), and badminton (5)] and had been suffering from recurrent or constant shoulder impingement symptoms for at least 3 months. After an initial screening in the course of which the impingement was diagnosed by experienced practitioners, the subjects were assigned to a pretty simple, daily exercise program that consisted of four exercises

• 

  Image 2 (De May. 2012): Images of the exercises in the same order as in the description to the left: Prone extensions, forward flexion, external rotation, horizontal abduction + external  rotation from 90° position of flexion

  Prone extension (similar to this, but if possible weighted) - The subject is prone with the shoulders resting in 90° of forward flexion. From this position, the subject performs bilateral extension to a neutral position with the shoulder in neutral rotation. 
• Forward flexion in side lying (similar, but lying on the side)- The subject is in a side-lying position, with the shoulder in neutral. The subject performs 90° of unilateral forward flexion in a sagittal plane.
• External rotation in side lying (view) - The subject is side lying with the shoulder in neutral position and the elbow flexed 90°. From this position, the subject performs 90° of external rotation of the shoulder with a towel between the elbow and trunk to avoid compensatory movements.
• Prone horizontal abduction with external rotation (like this, but with arms moving into the position shown in image 2) - The subject is prone with the shoulders resting in 90° of forward flexion. From this position, the subject performs bilateral horizontal abduction to a horizontal position, with an additional external rotation of the shoulder at the end of the movement.

à 3 sets of 10 repetitions each, with 1 minute rest between sets and a weekly randomized exercise order (to ensure you train all muscle parts equally and don't just replace one imbalance with another one). Before and after the 6-week intervention period, the participants had to answer a standardized questionnaire (the Aside from a questionnaire, the so-called "Shoulder Pain and Disability Index" (SPADI; cf. Brechenridge. 2011) and were hooked up to an EMG apparatus to measure their specific muscular activation patterns.

Figure 1: Pre- and post maximum voluntary isometric contraction (MVIC) in manual muscle test positions specific to each muscle of interest (value expressed relative to mean EMG activity for all 4 muscles; left) and absolute changes in EMG activity during arm elevation (right) from pre- to post intervention (De Mey. 2012)

The MVC data in figure 1 (left) was obtained in manual muscle test positions specific to each muscle of interest and in 5-sec MVIC intervals with 5 seconds breaks in between the activation. And yielded the following insights (De Mey. 2012):

• all 3 trapezius muscle parts exhibited increased maximum voluntary isometric contraction (MVIC) values after the exercise program (figure 1, left)
• all 3 trapezius muscle did contract less forcefully during arm elevation, while no change was seen for the serratus anterior (figure 1, right)
• the upper trapezius to serratus anterior (UT/SA) ratio significantly decreased after the training program, whereas the UT/ MT and UT/LT ratios did not change (data not shown).

Image 3: Illustration of the anatomy of the subacromial space

The significantly improved Shoulder Pain and Disability Index (SPADI) score (29.86 to 11.70 after 6 weeks; .60% reduction on average; 7 patients were basically pain-free after 6 weeks!) has therefore to be considered a result of a combined reduction of trapezius activation (not strength!) during the scapular plane elevation and the concomittant increase in the UT / SA ratio, which probably left more space for the impinged tendons to pass through the narrow subacromial space (see image 3).

Judged based on the results of other studies and what is generally described as a significant improvement in SPADI scores (8-13.2pts) in the literature, the researchers point out that

...[i]n our study, this was the case in 23 athletes. In 7 players, full recovery was attained based on a SPADI score of 0 during postmeasurements. The results of this study are very promising since limiting shoulder symptoms in active overhead athletes suffering from persistent mild symptoms might serve as a secondary injury prevention measure, limiting continued low-grade shoulder pain, fear avoidance, and ultimately surgical management requirement. (De Mey. 2012)

If the prospect of surgery-free total pain relief is not enough to invest a couple of minutes into rehab everyday, you are either the laziest slacker, I know, or don't know how f*** bad that hurts and how debilitating a chronic injury like this can be!

Implications: So, regardless of whether your shoulder does already hurt or you are smart and willing enough to spend a couple of extra minutes on "prehab" exercises I highly suggest that you

• don't be stupid and take 2-3 weeks off from all your regular upper body exercises and focus on working on the muscular imbalances which are the underlying reason of existing shoulder pain in 90% of the cases to then gradually resume your regular training with light weights and low(er) volume on all those pushing movement the average gymbro loves to do
• be smart and incorporate 2 of the exercises into every other workout to make sure that you can preserve your presently pain-free state and don't end up ruining your progress, just because your ego told you that it would look better to do another 5 sets of bench presses than a couple of prone extensions and external rotations

And don't forget to revise your complete training regimen - are you doing the same number of sets for your upper chest and front delts as you do for your whole back? If so, it's about time for a more balanced regimen, one that will not only help you prevent muscular imbalances in the first place, but also facilitate constant progress towards a symmetrical and aesthetic physique.

You Want to Learn About the 'Best' Exercises for Shoulders & Co? Look No Further!

Chest	Biceps	Back	Core	Legs	Triceps	Shoulders
The SuppVersity EMG Series can help you in deciding which exercises should be part of your next workout routine.

References:

• Breckenridge JD, McAuley JH. Shoulder Pain and Disability Index (SPADI). J Physiother. 2011;57(3):197.
• De Mey K, Danneels L, Cagnie B, Cools AM. Scapular Muscle Rehabilitation Exercises in Overhead Athletes With Impingement Symptoms: Effect of a 6-Week Training Program on Muscle Recruitment and Functional Outcome. Am J Sports Med. 2012 Jul 11.
• Lo YP, Hsu YC, Chan KM. Epidemiology of shoulder impingement in upper arm sports events. Br J Sports Med. 1990 Sep;24(3):173-7.

HIIT is the Hit! Interval, not Steady State Aerobics is the Way to Go - Even for Patients with Myocardial Infarctions!

Image 1: Right in the starting block is where heart health begins... and on the finish line of a marathon race probably is where heart health ends (if not much earlier)

I think it is unnecessary to pose this question again, but in case you missed the innumerable blogposts, where I asked you whether you would rather like to look like an ultra-endurance runner or like a sprinter - here you go: Whose physique would you rather want to have? The sinewy physique of Haile Gebrsellasie or the muscled physique of Usain Bolt and co? I assume in most cases this question is unnecessary... but what if you are sick, obese or even have a heart failure? Obviously you cannot train like a sprinter, then... can you? Yes, you can - at least within your personal physiological limitations! In view of the results of a recent study from the KG Jebsen Center of Exercise Medicine at the Norwegian University in Trondheim, Norway, aerobic interval training would even be the healthier choice (Moholdt. 2011)!

For their study Trine Moholdt and her colleagues recruited 107 patients who had been hospitalized for myocardial infarction 2-12 weeks before the study and randomly assigned them to usual care rehabilitation or an aerobic interval training performed. In the course of the 12 week study period the exercise protocol was performed thrice a week. Two sessions were supervised, the other one had to be performed at home.

• usual care rehabilitation program - the standard program comprised 60 minutes of aerobic exercises performed to music; the sessions were lead by a physiotherapists, and after a 10-minute warm-up, the patients did aerobic exercises like walking, jogging, lunges and squats for 35 minutes, which were followed by a 5-minute cool-down with stretching and relaxation exercises.
• aerobic interval training - the total session time of the interval training was 38 minutes; it consisted of an 8-minute warm-up, followed by 4x4-minute intervals at 85–95% of the maximum heart rate (monitored by heart rate monitor), with active rest of 3 minutes of walking at 70% of maximum heart in between the intervals; the exercise session was terminated with a 5-minutes cool-down.

In view of the still commonly held believe that interval training could easily become (over-)exerting, quite a few medical practitioners, would probably shake their heads over the "irresponsibility of [their] Norwegian collegues - how dare those idiots put ailing cardiac patients on such an tortorous exercise regimen" ... I think I won't have to continue, you know the whole litany... and if you, just like me cannot stand that anymore, and your own (your father's, mother's, grandpa's or grandma's) doctor is one of those, take the following data, print it and use it to shut him up.

Figure 1: Improvements in VO2Max, peak heart rate, respiratory exchange rate at peak heart rate and heart rate recovery in cardiac patients after 12 weeks on the usual care rehabiliation program or an intense aerobic interval training (data calculated based on Moholdt. 2011)

Obviously, the poor cardiac patients did not only survive the "torture", their hearts even thrived on it. The increase in peak oxygen uptake (VO2Max), the standard measure of aerobic performance, was 2.7x higher in the interval group than in the patients who did the usual 60-minutes reha-sessions (cf. figure 1). For the other parameters the differences were not statistically significant after analysis for initial randomization:

Flow-mediated vasodilatation, both non-normalised and normalised to shear stimulus, increased significantly after exercise training in both groups [...] Quality of life increased significantly after exercise training (between-group differences, not significant)

If we look at the blood parameters, however, we do yet see some interesting differences, even your medical practitioner could not argue away:

Figure 2: Changes in high density lipoprotein and adiponectin in cardiac patients after 12 weeks on the usual care rehabiliation program or an intense aerobic interval training (data calculated based on Moholdt. 2011)

While the changes in triglycerides, CRP, ferritin, haemoglobin, and glucose were - within their respective standard-deviations - identical in both groups, there was a marginal but statistically significant greater improvement in high density lipoprotein (HDL) levels (a statistician would say there was an improvement in the interval group, while there was none / no statistically significant one in the reha-group) in the interval group. While this would indicate a lower risk of future (recurrent) heart disease, the accompanying  increase in adiponectin would suggest that the interval training group either had already or were about to lose more body fat than their endurance trained peers.

Unfortunately, the body composition of the patients was not tracked in the study, so this leaves us with the "surprising" benefits of intense interval training for the hearts of patients with prior myocardial infarction as the main result of a study some medical practitioners would probably not even have dared conducting.