Twice in the last month I’ve gotten a calf cramp in my right calf during a zwift race. They both occurred following a climb while soft pedaling on a descent. The first one was 4/29 and took about 3 days to resolve. Just had one again last night, the race itself wasn’t very hard when it happened. It took about a mile to recover, I was able to get away from the group that caught me and to do an 18 minute sweet spot interval after the race. Calf is still sore today though.
Cramps are a complicated issue.
Nutrition, hydration are the first things to look at.
It could be fitness if you are not used to pushing that hard for that long. Over worked muscle.
You could try magnesium as a supplement. It helps the muscle release after the initial contraction. If it won’t release then we get a cramp.
My opinion on cramping is that it usually happens when we ask a muscle to do something it’s not prepared for. That encompasses things like hydration, fueling, etc., but many times cramps happen when we create a demand on the muscle via excess force, excess repetitive force, etc. There can be acute issues (where a singular contraction is more forceful than you’re used to) or a more compound issue (pre-fatiguing fibers and then asking for a big contraction), or just overall fatigue even from prior days or cumulative from a hard training block.
I work with a lot of my athletes (especially ultra distance guys) on preventing cramps by doing quite a bit of neuromuscular work where we’re generating high torque, and big, forceful contractions early in their training, and then we look for doing harder efforts after long rides (pre-fatigue) to make sure their bodies are prepared to do hard work when tired.
So there’s a number of things that can contribute to cramping, but it sounds to me like it’s probably related to some pedaling mechanic that changes following the hard climb and you get specific fibers in your calf that are maybe firing differently than when you were grinding up the climb.
If you want to post your race power file here and point out where the cramp occurred, maybe we can see something? Without knowing your fitness and rider profile, it can be tough to answer these kinds of questions.
The suggestion about Magnesium is a pretty good one as lots of people can be somewhat deficient, but many sport supplements provide it, and a diet rich in nuts, seeds, legumes, and leafy greens will provide more than enough to prevent deficiency issues.
There have been a lot of studies trying to get to the bottom of cramps. The short answer is that a definitive answer is not yet available. The physiology (I.e. what is actually happening in the muscle) js well understood. The reflex arc is being overstimulated as if the spindle is being overstretched when, in fact, it is not. But HOW this happens is elusive.
The fact that most cramps involve muscles that span 2 joints and are often unilateral makes things like hydration and electrolyte deficiency unlikely to be the root cause. There is also a familial predisposition implying a genetic component. This is not to say that bike fit, electrolytes, temperature and hydration have no impact, it’s just that they don’t explain it all.
All that said, the most widely accepted underlying cause is overuse of a muscle group beyond its limit often followed by long isometric contraction. (Long, surgy climb trying to hang on to the lead wheel followed by a cold twisty descent where you’re not pedaling but mashing the outside leg into the pedal). If so, the solution is to train that group in a way that induced cramps to force adaptation.
Some people report success with remedies that irritate the pharynx (pickle juice, cinnamon etc) with the theory that this cranial nerve activation relaxes the spinal reflex arc. There are also electrolytes with Mg and Ca that advertise cramp relief (10,000 Volts is one brand). These are supplements so you know the limitations regarding efficacy and safety.
Drop your saddle height by 3-5 millimeters before your next virtual race. Keeping your heel up on steep descents stretches the calf under tension and causes it to lock up. Try doing some light, unweighted calf raises during the week to build up muscle tolerance.
I would 100% agree that simply doing the sustained climb (after the punchy climb, too), followed by driving the outside foot down on turns could be a cramp mechanic… but not on a Zwift ride, that’s the oddity here. Unless he was standing and soft pedaling, I don’t see how he’d get that same stimulus.
Whether the former or the latter recommendation, I would tend to think it’s something with your fit or how your body is interacting on the bike specifically on the trainer. I wouldn’t think you applied excessively high demand during that race given that power profile. If you had really overcooked that first punchy climb, it would’ve manifested earlier.
Moving cleats back is an easy thing to try, something that I did when I was racing given my relative strengths, and it definitely deloads your calves over the long haul. Triathletes are notorious for putting their cleats as far back as they can go to preserve their calves for their runs. I would probably start by sliding your cleats back some and see how you get on with it and if you cramp with it before I made any specific bike fit adjustments for simplicity (but rob’s comment is valid too). Just that saddle and other bike fit stuff can be a real rabbit hole once you go that route.
I’m a bit confused that you say the cramp took days to ease off. Are you sure it’s cramp? Maybe you’re carrying a slight strain or something else that flares up? I’ve never had cramp that wasn’t gone in more than half an hour, but tbf I don’t cramp much so maybe it’s different for you.
Maybe it’s a strain. It cramped during the rest and I could still feel it when walking up and down stairs. It wasn’t painful just something I could notice.
Severe “later”cramps can damage muscle tissue. This for me usually happens with those 3 hours later type cramps. It can take a few days to repair that damage in my case. Feels like a sore muscle when it should feel normal. If I even suspect that’s going to happen it’s straight to the magnesium capsules.
I say go, body says no.
