Michael Dell is smack-talking his buddy Marc Benioff to raise money for charity

Michael Dell and Marc Benioff are friends and Fitbit pal,s and now they've turned those things into a friendly rivalry for charity.

The CEO to log the most steps during a 5-day challenge wins, and Fitbit will donate $10,000 to American Heart Association in the victor's honor.

Both of these men are huge philanthropists, Dell with his own foundation and Benioff with his 1-1-1 foundation model, so there's more than a little pride at stake here.

As part of the challenge, Dell, who describes himself as "competitive" wasn't above dishing out a little smack talk at his friend, either, in a Q&A conducted by Fitbit.

For instance, he told the story of how he was talking to reporters at his Dell World trade show about big data using Fitbit. "We scrolled through my leaderboard to see how I was doing relative to my friends. I was way ahead of Marc that day too, so this should be a lot of fun," Dell said.

Benioff concedes that Dell regularly beats him on Fitbit, saying, "Michael and I have been friends for many years and he's actually called to check on me when my Fitbit shows that I've missed a few days. He logs an incredible amount of steps, so I know I am in for a challenge. I've joked before that I think Michael puts his Fitbit on his dog."

For the week, both are sharing their Fitbits stats and so far Dell is far ahead of Benioff. Dell has logged nearly 43,000 steps to Benioff's nearly 30,000. (On average, every 10,000 steps = about 5 miles.). Anyone can also join Team Dell or Team Benioff and donate money. For every dollar donated, the CEO gets 10 steps added to his total.

We're pretty certain Dell is feeling gratified by his progress over Benioff so far.

Dell said his mantra for this week was going to be #dellbeatsbenioff2015.

Here's the Q&A sent to us by Fitbit.

Fitbit: How has having friends on Fitbit like Marc Benioff / Michael Dell inspired you to be more active?

Michael Dell: I'm pretty active anyway, but I'm also competitive. Funny story. I was in a media interview at Dell World last fall, and we were on the topic of Big Data. I used my Fitbit as an example of the innate power of data to turn information into insights and actions. We scrolled through my leaderboard to see how I was doing relative to my friends. I was way ahead of Marc that day too, so this should be a lot of fun. J

Marc Benioff: Michael and I have been friends for many years and he's actually called to check on me when my Fitbit shows that I've missed a few days. He logs an incredible amount of steps, so I know I am in for a challenge. I've joked before that I think Michael puts his Fitbit on his dog!

FB: How do you see wearable devices evolving in terms of how they will continue to change consumers' approach to health and fitness?

MB: Fitbit is an amazing example of the power of wearables and data. It can track my location, my physical activity and my vital signs, like my heart rate. I have no doubt that in the future, wearable devices like Fitbit will know my blood pressure, hydration levels and blood sugar levels as well. All of this data has the potential to transform modern medicine and create a whole new era of personalized care.

MD: Wearable devices are here to stay, and they'll only get more sophisticated and effective as they evolve. Until now, most of us have made our health and fitness decisions based on what we think we know about ourselves. Advancements in technology - wearables and otherwise - will eventually take much of the guess work out of healthy living. And we'll all benefit from it.

FB: On a larger scope, where do you see the Internet of Things and connected devices going in the next five years?

MD: I think it's the next trillion-dollar opportunity for growth - and not just for my industry but for all industries. The productivity, efficiency and insights that all that connectivity will bring to bear in the world is how we'll continue to grow and thrive on a planet with a growing population and finite resources.

FB: Why are you participating in the Fitbit Celebrity Challenge benefiting American Heart Association?

MD: It's a worthy cause, and a good excuse to have to some fun with Marc.

FB: In fitness, just like in business, a little competition can be a big motivator. During this Fitbit Challenge, what will you do to stay a step ahead of Marc/Michael, respectively, and what's your mantra going to be?

MD: How about #dellbeatsbenioff2015? That has a nice ring to it.