Earth Day Challenge
April 22
| Name | Age | Location | Country | Affiliation | Distance |
|---|---|---|---|---|---|
| john marollo | 44 | USA | 6,683 | ||
| John Maroney | 47 | Hinsdale, IL | USA | 10,834 | |
| Piotr Maroszek | 35 | POL | Polish Indoor Rowing Team | 14,961 | |
| John Marple | 72 | USA | 7,000 | ||
| Scott Marquardt | 71 | Washington, DC | USA | 5,000 | |
| ULISSES MARQUES | 59 | SAO JOSE DOS CAMPOS | BRA | 6,008 | |
| Dorian Marques-Vigneron | 23 | FRA | 11,340 | ||
| Jim Marquez | 58 | Bethel, OH | USA | 10,000 | |
| Alejandro Marquez | 37 | MEX | 7,681 | ||
| James Marquez | 55 | Brentwood, CA | USA | Team Delta | 5,578 |
| Luis E. Marquez | 56 | Saint Johns, FL | USA | Navy | 6,424 |
| Renato Marquez | 42 | TX | USA | 6,008 | |
| Tom Marr | 19 | Lindisfarne, TAS | AUS | 6,099 | |
| Steven Marr | 46 | Denver, CO | USA | 6,103 | |
| Colin Marr | 67 | Orange, NSW | AUS | Team Diamonds | 18,835 |
| Alessio Marra | 57 | ITA | 8,335 | ||
| Stephanie Marra | 48 | USA | Engine by Carson (EBC) | 5,026 | |
| Stephen Marra | 32 | Tampa, FL | USA | Tampa Catholic High School | 8,000 |
| Mallory Marrero | 24 | USA | 6,877 | ||
| Joanne Marriott | 86 | Arvada, CO | USA | 5,868 | |
| Marshall Marriott | 90 | Arvada, CO | USA | 6,359 | |
| Karen Marriott | 54 | St Pete Beach, FL | USA | 5,000 | |
| Lyndon Marsalis | 56 | Westland, MI | USA | 12,337 | |
| Libby Marsden | 30 | GBR | 10,040 | ||
| James Marsden | 39 | GBR | 5,000 | ||
| Stuart Marsden | 68 | Tring | GBR | 13,558 | |
| Megan Marsh | 48 | Los Angeles, CA | USA | 11,907 | |
| Sam Marsh | 35 | AUS | 11,232 | ||
| Tim Marsh | 66 | Mansfield | GBR | The Diamonds (Over Sixties Erging Group) | 16,639 |
| Steve Marsh | 59 | Llantwit Major, South Wales | GBR | The Diamonds (Over Sixties Erging Group) | 10,065 |
| Marian Marsh | 56 | GBR | 7,783 | ||
| Ricky Marsh | 59 | St Helens | GBR | 5,762 | |
| Jay Marshall | 71 | USA | 6,479 | ||
| Mark Marshall | 58 | Dudley | GBR | Free Spirits | 5,500 |
| Jason Marshall | 40 | Port Coquitlam, BC | CAN | GARAGEATHLETE | 3,119 |
| Michelle Marshall | - | GBR | 5,485 | ||
| Daniel Marshall | 70 | San Francisco, CA | USA | Dolphin Club | 6,374 |
| Brett Marshall | 37 | TX | USA | 6,000 | |
| Gavin Marshall | 49 | Petersfield | GBR | Royal Navy (UK) | 7,103 |
| Kim Marshall | 58 | NZL | 11,213 | ||
| Kate Marsi | 42 | Portland, OR | USA | 10,385 | |
| Martin Maršík | 50 | CZE | 4,132 | ||
| Tom Marsland | 42 | Silverdale, WA | USA | 2,000 | |
| Danil Martakov | 32 | Houston, TX | USA | 21,119 | |
| Olivier MARTEL | 60 | Les Herbiers | FRA | 6,670 | |
| Jack Martell | 23 | USA | 5,286 | ||
| Roberto Martellono | 62 | ITA | 10,509 | ||
| Ralph Martens | 59 | Freehold, NJ | USA | 12,079 | |
| Ralf Martens | 35 | SUI | 10,960 | ||
| Lars Mårtenson | 58 | SWE | 4,905 |