Conditioning Research

This one looked interesting. Adding a few sprints to your basic steady state cardio added fun, did not feel harder and increaed energy expenditure... Adding sprints to continuous exercise at the intensity that maximises fat oxidation: Implications for acute energy balance and enjoyment. The objective was to examine the effect of adding sprints to continuous exercise at the intensity that maximises fat oxidation (Fat(max)) on energy expenditure, substrate oxidation, enjoyment and post-exercise energy intake in boys. Nine overweight and nine normal weight boys (8-12 years) attended the laboratory on three mornings. First, body anthropometrics, peak aerobic capacity and Fat(max) were assessed. On the remaining two sessions, resting metabolic rate was determined before participants completed 30 min of either continuous cycling at Fat(max) (MOD) or sprint interval exercise consisting of continuous cycling at Fat(max) interspersed with four-second maximal sprints every two minutes (SI...

how long is it since that Tabata study?  The BBC finally discover intervals I commented on this over at the Body By Science site Just watched the BBC Horizon programme and the key bit was about what they called HIT but was really HIIT - interval training on an exercise bike. This benefitted the subject who improved his insulin sensitivity but - due they said to his genetics - did not improve his VO2 Max. They explained how this intense exercise had an impact on his glucose metabolism, emptying his muscles of glycogen so that they were able to absorb more glucose form the blood. This was good in that we are inching along towards an understanding of the benefits of intense exercise, but disappointing in that we never seem to go the whole way from interval training to intense resistance training. If you really want to empty your glycogen stores and have some intense exercise, then go for BBS style HIT! The other thing was that I found it disconcerting that the scientist wh...

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Well, another week and another study on the benefits of interval training.  This time it is Gibala's team again (they have done other work on intervals in the past e.g. this )  from  McMaster University in Ontario. The news story is here Each session involved pedaling on a stationary bike for 10 repetitions of 60 seconds apiece at about 90 percent of maximal heart rate, interspersed with 60 seconds of rest, capped by a short warm-up and cool-down. Each entire exercise session lasted 25 minutes of which only 10 minutes was spent performing vigorous intensity exercise The muscle biopsies revealed higher amounts of mitochondrial proteins, suggesting that the high-intensity, low-volume training increased the numbers of muscle cell power generators, a marker of improved metabolic health. Although the training regimen didn't decrease body mass in any of the participants, it did increase the maximal workload that each was able to achieve on the stationary bike and decreased h...

Just a quick pointer to a couple of recent studies on interval traning: Effects of acute sprint interval cycling and energy replacement on postprandial lipemia Low-volume high-intensity interval training reduces hyperglycemia and increases muscle mitochondrial capacity in patients with type 2 diabetes

I mentioned this study a few days ago, but I was away from my computer so couldn't write much. The study is here . Towards the minimal amount of exercise for improving metabolic health: beneficial effects of reduced-exertion high-intensity interval training. It was done here in Edinburgh at Heriot-Watt University.  The protocol that was tested was of 3 easy 10 minute cycling sessions with a one or two hard 10 second sprints thrown in.  The result was an improvement in key health markers - insulin sensitivity and VO2 peak. The researchers see this as a great encouragement -  big benefits can come from relatively modest investments in time: In conclusion, in this study we have shown that a very brief and feasible exercise intervention is associated with improvements in metabolic health and aerobic capacity. Our findings suggest that this REHIT protocol may offer a genuinely time-efficient alternative to HIT and conven- tional cardiorespiratory exercise training fo...

Just a quickie before I go to work. I spotted this abstract pop up this morning. High intensity interval training alters substrate utilization and reduces oxygen consumption in the heart Aims : although exercise training induces hypertrophy with improved contractile function, the effect of exercise on myocardial substrate metabolism and cardiac efficiency is less clear. High intensity training has been shown to produce more profound effects on cardiovascular function and aerobic capacity than isocaloric low and moderate intensity training. The aim of the present study was to explore metabolic and mechanoenergetic changes in the heart following endurance exercise training of both high and moderate intensity. Methods and Results : C57BL/6J mice were subjected to 10 wk treadmill running, either high intensity interval training (HIT) or distance-matched moderate intensity training (MIT), where HIT led to a pronounced increase in maximal oxygen uptake. Although both modes of exercise ...

A nice report of a study from Norway Peak Oxygen Uptake and Cardiovascular Risk Factors in 4631 Healthy Women and Men Go and read it, but a few quotes: Research from the K.G. Jebsen Center goes well beyond the Dallas findings, and shows that fit 50-year olds can be as fit as 20-year olds who don't exercise much. But exercise -- how much, and how intense -- is the key to maintaining this fitness. When the Jebsen Center researchers looked at the importance of the intensity of exercise versus the duration, intensity was far more important than duration in determining peak oxygen uptake. They have also looked at the benefits of high intensity exercise in the form of interval training -- where four or more short periods (typically 4 minutes) of very high intensity exercise are followed by a similar number of short periods of lower intensity exercise. This approach, called 4x4 interval training, is a quick way to increase your overall fitness, research from the Jebsen Center has ...

I thought that this was an interesting article.   The journalist asked what different experts considered to be the single best exercise.   The conclusion seems to be hill sprints or at least sprints up stairs.  The approach seems promising, since most of us have minimal time to exercise each week. Gibala last month published a new study of H.I.T., requiring only a stationary bicycle and some degree of grit. In this modified version, you sprint for 60 seconds at a pace that feels unpleasant but sustainable, followed by 60 seconds of pedaling easily, then another 60-second sprint and recovery, 10 times in all. “There’s no particular reason why” H.I.T. shouldn’t be adaptable to almost any sport, Gibala said, as long as you adequately push yourself. Of course, to be effective, H.I.T. must hurt. But a study published last month found that when a group of recreational runners practiced H.I.T. on the track, they enjoyed the workout more than a second group of runners wh...

Here are a couple of other apps for the iPhone that I've been playing with.  Both are free : The Gymboss Interval Timer -  simple, flexible interval timer.    There are some programmed intervals and also the option to set up your own.  Basic, straightforward and it works. IF Timer -  a very simple timer that you can set up to time your fasting.  Click when you finish your last meal and choose how long you will be fasting.  It tells you how long you have left and how long the fast has lasted.  Basic....you could use your watch.....but it was free!  Perfect for Eat Stop Eat style fasts .

This is an interesting one from the perspective of much of what I put up here:  Sprints are more fun than endurance running.  Too many people give up on exercise because it is boring High-intensity interval running is perceived to be more enjoyable than moderate-intensity continuous exercise: Implications for exercise adherence. Abstract The aim of this study was to objectively quantify ratings of perceived enjoyment using the Physical Activity Enjoyment Scale following high-intensity interval running versus moderate-intensity continuous running. Eight recreationally active men performed two running protocols consisting of high-intensity interval running (6×3 min at 90% VO(2max) interspersed with 6×3 min active recovery at 50% VO(2max) with a 7-min warm-up and cool down at 70% VO(2max)) or 50 min moderate-intensity continuous running at 70% VO(2max). Ratings of perceived enjoyment after exercise were higher (P < 0.05) following interval running compared with continuou...

low volume sprints and high volume intervals have the same effect in terms of this aspect of gene expression......so why spend time doing doing the long stuff? Mitochondrial gene expression in elite cyclists: effects of high-intensity interval exercise Little is known about the effect of training on genetic markers for mitochondrial biogenesis in elite athletes. We tested the hypothesis that low-volume sprint interval exercise (SIE) would be as effective as high-volume interval exercise (IE). ............... We conclude that upstream genetic markers of mitochondrial biogenesis increase in a similar way in elite athletes after one exercise session of SIE and IE. However, since the volume and duration of work was considerably lower during SIE and since Tfam, the downstream target of PGC-1alpha, increased only after SIE, we conclude that SIE might be a time-efficient training strategy for highly trained individuals.

Nothing earth-shattering here - another study that indicates that sprint training has broad benefits: 10 or 30-s sprint interval training bouts enhance both aerobic and anaerobic performance These data indicate that 10-s (with either 2 or 4 min recovery) and 30-s SIT bouts are effective for increasing anaerobic and aerobic performance .

Interesting study - looks like interval training has specific benefits for people with high blood pressure Continuous and interval exercise training were beneficial for blood pressure control, but only interval training reduced arterial stiffness in treated hypertensive subjects. Effects of continuous vs. interval exercise training on blood pressure and arterial stiffness in treated hypertension.

This is a concept that hovers around a few training programmes and dietary approaches: training when you have low muscle glycogen either through prior intense exercise to deplete the glycogen (this is the approach Rusty takes in his Treadmill Ninja course ) or via a low carb diet. Good to see a study to look at the concept. Training in a state of glycogen depletion limited performance but increased fat burning. It would be interesting to see this compared with Phinney's work on low carb and endurance training. Training with Low Muscle Glycogen Enhances Fat Metabolism in Well-Trained Cyclists. PURPOSE:: To determine the effects of training with low muscle glycogen on exercise performance, substrate metabolism, and skeletal muscle adaptation. METHODS:: Fourteen well-trained cyclists were pair-matched and randomly assigned to HIGH or LOW-glycogen training groups. Subjects performed 9 aerobic training (AT; 90 min at 70% VO2max) and 9 high-intensity interval-training sessions (HIT; ...

Quite a few newspapers picked up on this study - e.g the Independent As usual NHS Choices calms things down and tries to maintain the paradigm! While this type of research may suggest theoretical benefits to short bursts of intensive exercise, it does not change the fact that regular, moderate-intensity exercise is good for our health. Anyway, this one adds to the evidence of the efficacy of intervals Here is what the researchers say : "We have shown that interval training does not have to be 'all out' in order to be effective," says Professor Martin Gibala. "Doing 10 one-minute sprints on a standard stationary bike with about one minute of rest in between, three times a week, works as well in improving muscle as many hours of conventional long-term biking less strenuously." A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms High-intensity interval training (HIT) i...

This one caught my eye because it was about High Intensity Exercise....so I thought Body by Science . Actually it is just another study on intervals. Intervals - good for cardiorespiratory fitness but not necessarily for: lowering the subjects resting heart rate, lowering fat percentage or reducing the ratio between total and HDL plasma cholesterol. Increasing total bone mass and lean body mass needs weight training. Interesting material. High-Intensity Training Vs. Traditional Exercise Interventions for Promoting Health PURPOSE:: to determine the effectiveness of brief intense interval training as exercise intervention for promoting health and evaluate potential benefits with reference to common interventions; i.e. prolonged exercise and strength training. METHODS:: 36 untrained men were divided into groups that completed 12 weeks of intense interval running (INT; total training time 40 min a week), prolonged running ( approximately 150 min/week), strength training ( approximately...

This debate seems to keep going. One minute everyone is talking about EPOC and Afterburn and the advantages of interval training....then it is back to the advantages of long low intensity cardio to burn fat..... Lyle McDonald had a good series on this recently ....Anyway, here is another study...which seems to point towards the advantages of low intensity exercise. Then again...it is not as straightforward as that.... Fat oxidation rate during and after a low- or high-intensity exercise in severely obese Caucasian adolescents Abstract The objective is to study the effects of low-intensity (LI) or high-intensity (HI) equicaloric exercises on energy expenditure (EE) and substrate oxidation rate during and after the exercises in severely obese Caucasian adolescents. Twenty obese boys (BMI-SDS 3.04 ± 0.52, %Fat Mass 38.2 ± 2.1%) aged 14–16 years (pubertal stage >3) participated in this study. Maximal oxygen uptake (V′O2max) and maximal fat oxidation rate were determined with indir...

We've mentioned Crossfit Endurance before . They use short intervals to train athletes for long distance endurance efforts. Interesting but controversial . Some guys here in Scotland are about to test the Crossfit endurance approach. On the 17th and 18th of October 2009 we’ll be conducting a wee experiment in human-powered distance covering. The West Highland Way, at just under 100 miles, is the ideal venue. Two road cyclists, two mountain bikers and two runners will leave Fort William on Saturday morning. The roadies will follow the A82 (including the detour to Kinlochleven, no slacking here) and the others will be sticking to the WHW route. The mtb and running records are around half an hour apart, so although the roadies will be sitting waiting with their feet up by the fire at the Real Food Café at the half way point, the rest is an unknown. While we’re not expecting to break any records, it’s still very much a test. The runners have trained using Crossfit. High intensity wei...

you know, I tend to think that Craig's sales pitches are way over the top, but to be honest his programmes - Turbulence Training - are pretty solid.