First things first, they say, “warm up! It’s very important”, the speaking subject being your PE teacher, personal trainer, your mum, whatever. And there we go with the advocated 10++ minutes on the tread, speed walk to light jog to get to the final aim of breaking sweat and beyond.
Then you usually move to the mats area and you begin stretching all your segments, 20+ seconds per position. Now you feel ready to lift, jump and throw. Have you ever asked why doing all such routine?
The answer sounds to you quite straightforward: warm and long muscles are less likely to injure and they are more performing. Sure? One of my lecturers would say “I don’t think wolves warm up and stretch before a hunt”.
The real answer, as often happens, lies in between the two extremes.
On one hand studies are controversial when analysing the ability of a warm up routine of reducing injuries. A stretched, warm muscle is more resilient and has the ability of absorbing more energy before failure, meaning that it is harder to tear it. Although, stretching a muscle may impair its contracting ability and muscle tension is what actively protects joints and muscles themselves from impacts. As a conclusion, we cannot rule out that stretching could actually increase injuries rates.
On the other hand, a warm muscle has been shown to contract faster and more powerfully. This could save joints from oblivion and make us perform better. Is it enough to jog before an upper body strength session or a long jump contest and is it all about having your muscles warm?
The heat which warms muscles is a consequence of the muscle contraction itself that like all efficient engines cannot be 100% efficient, turning some energy into heat. Temperature is not the only thing that changes in the muscle after a series of contractions and the intensity, type and duration of contractions is ultimately affecting muscle functioning, as it is the case with fatigue after exhausting efforts.
Naming it in a more pompous fashion, contractile history affects muscle performance.
If a contractile history of 10 minutes of light jog might be enough to warm up at least some of the muscles involved in your following, main event of the day, this does not get you ready to perform at your max power and allow you to clear your new PB.
Good news is that a hectic contractile history does not necessarily lead to fatigue but may improve performance as well. Muscles have a property called Post-Activation Potentiation (PAP) in which a conditioning activity (a previous heavy effort) temporarily increases rate of force development, allowing you to throw farther, jump higher and whatever requires power.
Rather than a tedious and endless cycle at 20 rpm and stretch to death I would suggest you get specific, with dynamic efforts involving similar movements to those you are going to perform later in your menu, building up intensity.
Be aware that a conditioning activity is fatiguing and if exaggerated the strain may offset the PAP benefit. Follow the advice of a brand new meta-analysis: perform a few reps at 60-80% of your max, 7-10 minutes before the main power training session. In jargon this is called complex training and allows you to develop greater power and to stimulate faster fibres.
In a competition like high jump this occurs naturally as lower precedes higher bars, usually in a progressive manner and if you design your plan well you might take advantage of PAP when you most need it without getting too tired.
So is warm up all about warming your muscles up, or is this its real meaning?
Wanna now more of PAP and complex training?
Wilson et al 2012 Meta-Analysis of Post Activation Potentiation and Power: Effects of Conditioning Activity, Volume, Gender, Rest Periods, and Training Status
Sale 2002 Postactivation potentiation: Role in human performance
Injuries and warm up:
Woods et al 2007, Warm up and stretching in the prevention of muscular injury
Shrier 2008 Warm up and stretching in the prevention of muscular injury: Reply