SportLegs is a supplement that contains vitamin D, calcium, magnesium, and lactate. Based on the ingredients it doesn't seem like SportLegs should do a whole lot. The makers claim "It primes muscles with lactate, your muscles' natural fuel, so they make less lactic acid. It works better than electrolytes, without sodium or painkillers." and "Bicycling magazine's testers conclude, 'SportLegs really works. It pushes back the point where your legs start to 'burn' during hard efforts, allowing you to ride harder, happier.'" The website looks pretty gimmicky with a lot of testimonials and not a whole lot of real information (as a scientist I'm a big fan of double blind studies and from what I can tell, they haven't done any). But then they have all these testimonials. Sure a lot of them are sponsored athletes, but the majority of sponsored athletes are probably getting nothing more than free product. So they obviously think the product works if they want to get it for free. And if you dig a little deeper on the website you can find some supported sciency claims.
Obviously magnesium and calcium are important in muscle contraction and relaxation and in ATP production (adenosine triphosphate is the energy that cells use, food eaten is eventually broken down into ATP). But I didn't realize they can be limiting factors in skeletal muscle fatigue and ATP production.
My Experience with SportLegs
I first tried SportLegs back in 2007 when Jeff first started working for Performance, I think we got a free sample bottle. I honestly don't remember if I thought they did anything or not. I do remember looking at the ingredients and thinking they shouldn't do anything. I only used them a couple times and didn't give it any more thought. Then while I was training for Ironman Cozumel 2011, my legs kept feeling tired and sluggish, especially at the beginning of rides. It would sometimes take me 1-2 hours to get warmed up, feel decent and be able to ride at my normal long ride pace (which is only about 14-15 mph so riding at 12mph was really brutal!). Sometime in February after Ironman Cozumel 2011, I found a bottle of SportLegs at home and decided to try them before a ride, I had a great ride! My legs felt great from the start! I assumed it was just a fluke, or placebo effect, but I kept using them and my legs kept feeling great! Even on some really tough rides like Marble Falls and the Easter Hill Country Tour! So I've continued to use SportLegs for most of my rides this season, even most of the short ones and I have only had that tired sluggish legs feeling 2 or 3 times this year. Does that mean SportLegs work? I have no idea, it could be placebo effect, it could be that my legs are getting stronger, or it could be something else. Then I got on the bike at the Austin Tri on Monday and my legs felt awful- that tired sluggish feeling is NOT what you want at a race! I kept trying to figure out why my legs felt like crap and why I just couldn't pedal as fast as I wanted. About halfway through the bike I realized I hadn't taken my SportLegs that morning...hmmm, interesting.
The other thing that I find interesting is that SportLegs claims to stop "the burn" but my issue isn't really lactic acid build up after riding hard for awhile. My issue is icky feeling legs from the minute I start to ride. This from the SportLegs sciency page may in part explain my issue:
- "How taking SportLegs first helps performance: SportLegs uses lactate, your body's primary high-exertion muscle fuel, to signal muscles not to overproduce lactate before you even begin exercise. Muscles switch from lactate overproduction to net lactate consumption in response to a rise in blood lactate concentration, regardless of whether blood lactate is raised naturally or from exogenous infusion (7,8,9,10,11,12,13). That's precisely what SportLegs accomplishes. It's 86.4% lactate. Taken an hour before exercise, SportLegs raises blood lactate, so you experience exercise with less limb "pump" and heaviness, and improved lactate transfer facilitates a noticeably higher Lactate Threshold"
What do you think of SportLegs? Have you used them? Do you feel like they work?