Home > Uncategorized > All exercise performances are sub-maximal

All exercise performances are sub-maximal

September 12th, 2011

Another interesting pacing study, with many similarities to the one I blogged about last week, published once again in Medicine & Science in Sports & Exercise. Cyclists are asked to do a series of 2,000-metre time trials in a pseudo-virtual reality set-up. Most of them they perform solo, but in one of the trials they race against a virtual competitor (who, unbeknownst to them, is actually programmed to exactly mimic their own previous trial). The result is obvious: competition improves performance, so they’re able to beat their doppelganger and race significantly faster.

What’s interesting is how they manage to beat their previous performance. Throughout the race, the power generated from aerobic sources is exactly identical in all the different trials. But the power from anaerobic sources is significantly higher in the “racing” scenario during the second half of the race (during the last 90 seconds or so, in other words).

What does this mean?

Consequently, it has been argued that all exercise performances are sub-maximal, since they are terminated before there is a catastrophic metabolic or cardio-respiratory failure, and that a physiological ‘reserve’ capacity will always remain. The ergogenic effects of the [head-to-head] competition might therefore result from the central influence of some motivational or dissociative effect enabling the use of a greater degree of the physiologic ‘reserve’ capacity.

That’s actually quite a powerful statement: “all exercise performances are sub-maximal.” If the stakes are raised sufficiently, you can always squeeze out a little extra. I think most of us grow up knowing this intuitively, but at some point — after we start learning about VO2max and lactate threshold and so on — it’s often forgotten.

  1. Chrisp
    September 13th, 2011 at 02:30 | #1

    Agreed I am sure the same holds true for momentary force contractions during a fight or flight situation. The amazing abilities that the body can produce to save a life.
    I think this is still a carryover from evolution. First one to make it to a meal wins!

  2. Andrew Rawson
    September 14th, 2011 at 03:11 | #2

    Fine and true, but do we want all exercise performances to be maximal? Isn’t there something to be said about working various areas and then resting, and then over time we improve and then when we need to be maximal we have it, rather than wear ourselves out each day and not being ready to work another aspect tomorrow, or what am I missing?

  3. alex
    September 14th, 2011 at 03:41 | #3

    @Andrew: “Isn’t there something to be said about working various areas and then resting, and then over time we improve and then when we need to be maximal we have it…”

    Sure, nobody’s recommending that you try to be “maximal” in every day in workout. What the researchers are suggesting is that ALL sustained physical exertion is submaximal — even when you “need to maximal.” So even if you’re sprinting down the final straight of the Olympic final a half-stride behind the leader (a situation where you’d expect to maximal), you’d manage to find an extra burst if a tiger jumped out of the crowd and started chasing you. If you were truly maximal with nothing held in reserve (these researchers argue), your oxygen-starved muscles would go into rigor and you’d die.

    In practice, this is more of a thought experiment than an argument that we should hire tigers to leap out of the stands at track meets. The point is that in any effort lasting longer than, say, 30 seconds, we’re pacing our effort — and that means that the brain is controlling the level of exertion, not some absolute physical limitation somewhere in the body.

  4. Frank
    September 15th, 2011 at 20:57 | #4

    Most all of the “thought experiments” here are composed from the perspective of the winner. I’ve come second in many races where I was doing everything I possibly could to claw back the winner all the way to the line, yet still coming up short, sometimes by inches. Perhaps I could have gone harder if a tiger was chasing me, but it seems much more likely that I would produce a maximal effort under these circumstances than in the cases where I’m going up against another rider and beating him/her.
    Some of my personal examples that I can think of where I came up just short (and sometimes when I won) involved massive cramping and collapse in the middle of a sprint, being so blown after the loss that I could not dismount from my bike without assistance, going into gagging fits, etc.

  5. September 18th, 2011 at 09:29 | #5

    As Frank points out, there’s an interpersonal aspect to this for which psychoanalysis has the concept ‘Projective Identification’. To quote from a piece I wrote for my running club newsletter: “When one runner passes another there’s an almost tangible exchange of energy. You hear somebody coming up behind you, then past they go, leaving you all the more conscious of your limits. ‘I don’t think I’m up to it today. Can I really be bothered? I’ve got such a lousy start-time! I never run well on cold mornings. Did I pay that cheque in last week?’ Almost imperceptibly, motivation and concentration leak away. You change from feeling positive and competent into feeling useless and defeated. If being overtaken turns you into a loser, passing someone else boosts your sense of can-do. I exploit this when I’m closing with someone in a race by overtaking them rather than staying companionably alongside as I would on a training run, mentally moving up a place in the finish order as they go down one. Alternatively I hang threateningly on their shoulder, evoking anxiety that they’ll pull me round but be unable to hang on to their lead.”

  6. September 18th, 2011 at 10:17 | #6

    Coming from endurance sports, I’ve often wondered if some people are genetically predisposed to push themselves closer to maximal effort than others. I had a guy run with me for the final 10km of an Ironman where I was running fairly within myself (not gunning for any great performance) yet that guy killed himself to keep up and promptly collapsed at the finish line and needed medical attention. Same goes for people I’ve seen at road races and time trials who throw up right after the finish and take hours to recover. Despite (or maybe because of?) some reasonably good results in races I’ve done, I’ve never been able to push myself quite so far that I’ve vomited or collapsed afterwards. There’s just something in my brain that won’t let that happen — my brain will shut down my body’s effort long before reaching my physical limit. Yet some people seem to be missing that auto shut-off switch?

  1. No trackbacks yet.