Food and Health Rethought

Sprints and Youthfulness - Exploring the connection - and how to start sprint training to reap the benefits - weight lifting tie in

So I came across this article

“Leukocyte Telomere Length is Preserved with Aging in Endurance Exercise-Trained Adults and Related to Maximal Aerobic Capacity” via @mercola.

OK, this is really cool - and interesting for anyone interested in fitness.

OK, so normally as you get older, your telomeres shorten and that causes a whole lot of aging related problems.

This is a small study, but it shows that telomere length is preserved - if you among those who do endurance exercise… and it’s related to your so-called VO2 max - which is basically an estimate of the most oxygen you can consume during exercise…it’s a measure of how hard you can push yourself doing a sprint in any number of different types of exercises.

This is interesting because a number of studies have demonstrated that doing short sprints is actually more effective than aerobic workouts in terms of cardiovascular benefits.

To me, this is an additional, important data point, that if you care about fitness, and you devote time to stay in shape, you really owe it to yourself to do some sort of sprint - it doesn’t matter whether you’re sprinting up stairs or running your fastest - it’s about getting your heart, lungs, body, and body overall to go as fast as it can.

Here’s how runner’s world puts it :

Consistent aerobic conditioning will increase your max, but only by so much. French exercise physiologist Veronique Billat found that the fastest way to reach your potential is to run intervals at a speed that elicits your VO2 max, a pace known in lab circles as velocity. 

I suspect that improved cardiovascular fitness is directly tied to mental acuity and mood, and to me this is one very important molecular marker that sprints are quite important.

So the next question is if you’re going to start doing sprints at a gym or on a track, how should you go about it? Wikipedia calls sprint training HIIT (High Intensity Interval Training):

Usual HIIT sessions may vary from 9–20 minutes. The original protocol set a 2:1 ratio for work to recovery periods. For example, a runner would alternate 15–20 seconds of hard sprinting with 10 seconds of jogging or walking.

A HIIT session consists of a warm up period of exercise, followed by six to ten repetitions of high intensity exercise, separated by medium intensity exercise, and ending with a period of cool down exercise. The high intensity exercise should be done at near maximum intensity. The medium exercise should be about 50% intensity. The number of repetitions and length of each depends on the exercise. The goal is to do at least six cycles, and to have the entire HIIT session last at least fifteen minutes and not more than twenty.

A study by Gibala et al.^[5] demonstrated 2.5 hours of sprint interval training produced similar biochemical muscle changes to 10.5 hours of endurance training and similar endurance performance benefits. 

A recent study by Driller^[11] showed an 8.2 second improvement in 2000m rowing time following 4 weeks of HIIT in well-trained rowers. The interval training used by Driller and colleagues involved 8 x 2.5 minute work bouts at 90% of VO₂max, with individualized recovery intervals between each work bout

Recently it has been shown that two weeks of HIIT can substantially improve insulin action in young healthy men.^[12] HIIT may therefore represent a viable method for prevention of type-2 diabetes.

So, if those are the basic parameters, what is optimal? As this site says,

elite athletes cannot sustain an all-out effort for more than 60 seconds, which means the average exerciser’s full speed limitations are probably closer to 15-30 seconds. 

If the goal is to be able to increase your sprinting ability - and improve the lengths of your sprints, it seems to me that sprinting intervals should be as close to your max as possible for as long as you can sustain that maximum. The rest interval would be about half of that amount, but can vary.

As this article suggests, there may be other reasons to keep your sprint short. 

Studies also show that shorter intervals don’t feel as physically demanding as long intervals — so you can get better results without feeling like you’re working harder.

The article mentions myoglobin which holds oxygen, which is used to burn fat during fast sprints. 

Myoglobin holds enough oxygen to last for 5-15 seconds [Astrand, I., & Astrand, P-O. (1960). Myohemoglobin as an oxygen-store in man. Acta Physiologica Scandinavica, 48, 454-460]

myoglobin is repeatedly used and reloaded during the work and recovery phases of interval exercise.

This is another reason why an all out sprint is limited in terms of time.

Interestingly this may also be related to how weight lifters typically limit their number of repetitions to about 8 reps. That’s the maximum “sprint” that a muscle can maintain. In this view point, myoglobin could almost be view as the lungs of the muscle, and that you are partly working to improve the respirative ability of muscles. In my view this is likely one reason why shorter sets work for muscular development. However it also suggests to me that some may be able to sustain a longer “sprint” and that may be effective, provided they work towards muscle exhaustion. Indeed other studies have shown that as long as the muscle reaches failure - or comes close, lower weights and higher reps may have more benefits. It just takes a lot longer to reach failure with lower weights.

So, with sprints the idea is that doing sprint training for 20 minutes provides the cardiovascular benefits of lifting a lower weight for much longer. Similarly with weight training doing 3 sets or sprints to failure provides the benefits of a much longer workout.

Indeed people who train for power lifting (low rep, high weight), also have longer telomeres than age matched controls.

As see it, any type of sprint, whether it’s on a track, on a rowing machine or stair climber, or on a set with heavy weight spurs more rapid gains in terms of growth in fitness than so called endurance workouts, and it appears they help make you more youthful as well. Telomeres are just a marker, so my guess is that those who sprint and lift have better skin, more energy etc. than people of a similar age who do not do those same activities.